DIYstompboxes.com

DIY Stompboxes => Building your own stompbox => Topic started by: Skruffyhound on December 17, 2009, 07:24:55 PM

Title: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on December 17, 2009, 07:24:55 PM
I finished mine this evening (bar the box - which makes four without an enclosure in the last week :icon_redface:)

Mad little effect. I wasn't overly impressed when I fired it up, but now 5 hours later and I'm still tinkering with it, I think that says something about how many tones and nuances there are, and I haven't even started adding other effects to it.

I had to flip the LED round to get it to light up and change out the 4K7 resistor to a 1K. I've got ticking on many settings but I'm hoping that shorter wires and shielding in/output will sort that out. The extra 10uF cap had no effect on ticking and may actually have made it slightly stronger, it also had a radical effect on the tone -so there was another round of tweaking, in the end I left it off for now.

This circuit makes some great sounds but is probably not very stage friendly. Every channel change you have to re-bias, adjust guitar volume/tone, amp and effect level and maybe switch pickups to get the best out of it. Fun to tweak, but not maybe so much fun while the audience is waiting impatiently.

Don't even think about leaving the bias as a trimpot, it needs to be outside the box. I couldn't find trimpots small enough to get four side by side on this board anyway. Taylor did a great job with the PCB's beautiful to build on, but that would be my one criticism, that the trimpots could have been given a bit more space.

There is too much treble on many settings so it needs to be EQ'd to deal with that, if anyone has any good ideas where to squeeze a cap into this circuit to take a little of the top end I'd be interested in suggestions.

That's it for now, I'm happy. Thanks Taylor for the PCB's, Josh for getting the ball rolling with a great build report and of course Roy Gwinn
for designing it in the first place.

The Threads ;
http://www.diystompboxes.com/smfforum/index.php?topic=79012.0 (http://www.diystompboxes.com/smfforum/index.php?topic=79012.0)
http://www.diystompboxes.com/smfforum/index.php?topic=79078.0 (http://www.diystompboxes.com/smfforum/index.php?topic=79078.0)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on December 17, 2009, 07:59:33 PM
It's definitely a fun effect--I haven't built one on Taylor's board yet--too much other stuff going on.

However, for your 'too much treble' problem--I'm assuming this is on the VCF side of things--try backing off on the depth pot. I found that doing this lowered the frequency of my dry signal, so it sounded like a fixed wah, without depleting the higher frequency end of the LFO sweep.

My only complaint with the first one I built is that it can't handle much of an input signal without distorting harshly--however, there's a ton of gain on tap at the output. With this in mind, I might fiddle with the input--maybe use a fixed voltage divider or something to drop the front-end gain.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on December 18, 2009, 02:36:25 AM
I had to flip the LED round to get it to light up and change out the 4K7 resistor to a 1K. I've got ticking on many settings but I'm hoping that shorter wires and shielding in/output will sort that out. The extra 10uF cap had no effect on ticking and may actually have made it slightly stronger, it also had a radical effect on the tone -so there was another round of tweaking, in the end I left it off for now.

This circuit makes some great sounds but is probably not very stage friendly. Every channel change you have to re-bias, adjust guitar volume/tone, amp and effect level and maybe switch pickups to get the best out of it. Fun to tweak, but not maybe so much fun while the audience is waiting impatiently.

Don't even think about leaving the bias as a trimpot, it needs to be outside the box. I couldn't find trimpots small enough to get four side by side on this board anyway. Taylor did a great job with the PCB's beautiful to build on, but that would be my one criticism, that the trimpots could have been given a bit more space.

There is too much treble on many settings so it needs to be EQ'd to deal with that, if anyone has any good ideas where to squeeze a cap into this circuit to take a little of the top end I'd be interested in suggestions.


Thanks for this.

Arg you're right, the LED is labelled backwards. I will need to change it on the PDF. The LED resistor is going to be different for everybody depending on what LED you use - what color did you use?

Strange about the ticking. I didn't have much ticking to begin with, but the cap fixed what ticking there was. I saw someone mention somewhere that a smaller value would be better. Were you able to set yours up using a scope? If your ticking is really bad you might not have the LFO tweaked quite right.

Sorry about the trimpots, I thought I had made them work for different varieties but I always use these:

http://www.mouser.com/Search/ProductDetail.aspx?R=T73YB102KT20virtualkey61330000virtualkey72-T70YB-1K

and they fit with some extra room.

Let's make this the build thread; everybody can post their questions, comments, build reports and photos here.

Edit: ok, the PDF has been updated.

http://www.aronnelson.com/gallery/main.php/v/Taylor/
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on December 18, 2009, 02:17:41 PM
Quote
backing off on the depth pot
Thanks Josh, I'll check it out.
Quote
distorting harshly
Ha Ha, you're not kidding, that's why I'm tweaking the bias the whole time, but my gut feeling(without having looked at it too closely) is that the differences in how hot your signal is are minimal (hard strum/soft strum) its just that they are accentuated exponentially by the gain structure of the circuit, so you would have to interrupt  that somehow and when it differs with each channel that leaves you doing something similar to twiddling with the bias. You have the Mrk 1 version however, maybe there are some differences.

Quote
Let's make this the build thread; everybody can post their questions, comments, build reports and photos here
.
Good idea, I'm really interested in how it turned out for everyone else, and what mods people will figure out.

I used a green LED, ultrabright 5000MCD, about 1 lumen if I assume 30 degree beam. They are not very powerful in reality, but I thought it might be more pleasant than a really in-your-face powerful colour. Soothingly indicative.

I had my new scope on the signal, but just as a general indicator, and I tuned by ear using your instructions from the build Pdf. I think it's really clear where the sweet spots are. However, you could always pull back a bit to loose some ticking, but by doing that you lose the best of the effect. I will wait until I shield the in/out, then the switch if necessary and finally the rotary switch if I really have to, before I tame the effect down. I wired the rotary with 3 strand ribbon on a connector socket, quite fiddly, so I'm loathe to do that again, but that could be the problem.

Quote
the cap fixed what ticking there was. I saw someone mention somewhere that a smaller value would be better
OK, I'll try it out.

Quote
Sorry about the trimpots
No Problem, while I was searching my pile of old audiophile junk I found a huge stash of Alps trimpots that I hadn't seen before, so my Gristleizer has more mojo now even if they have to lean over a bit to fit in. :icon_mrgreen:

Thanks guys, I'm enjoying this effect a lot.
Aston
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on December 18, 2009, 06:02:45 PM
I am really having fun with this :icon_mrgreen:
Probably the most interesting pedal I've made, Clarinot cubed was good too, but I'm working on filtering for that before I'll really be happy.
Anyway, tried a bunch of different caps from pF values to 100uF, no effect on ticking but it becomes apparent that a possible mod might be to put switchable caps in this position, I'm getting a lot of different tones out of this. I need to be a bit more systematic and see if they are available elsewhere, there's easily 50 different settings on this thing.
Also a little interested to implement a dying battery pot on the whole circuit and see how that interacts with the bias. 
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: svstee on December 20, 2009, 07:32:41 PM
I am really having fun with this :icon_mrgreen:
Probably the most interesting pedal I've made, Clarinot cubed was good too, but I'm working on filtering for that before I'll really be happy.
Anyway, tried a bunch of different caps from pF values to 100uF, no effect on ticking but it becomes apparent that a possible mod might be to put switchable caps in this position, I'm getting a lot of different tones out of this. I need to be a bit more systematic and see if they are available elsewhere, there's easily 50 different settings on this thing.
Also a little interested to implement a dying battery pot on the whole circuit and see how that interacts with the bias. 

Gristle Factory anyone?  ;D
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: svstee on December 22, 2009, 03:57:59 PM
Hey, I just got my board in and had  question. If you look at the image of the PCB Taylor posted in the Gristleizer PCBs for sale thread;
(http://img27.imageshack.us/img27/228/gristleizerpcbimage.jpg)

you can see a lot of small holes. There is one between the 47K and 470K resistors to the right of the TLO72 and one that would be under the 47K resistor left of pin 3 of the TLO72. What are these for? Sorry if there is a really obvious answer here, are they jumpers or what?

Thanks!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on December 22, 2009, 04:01:34 PM
They are just junction holes for the traces, you don't need to do anything with them.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: tiges_ tendres on December 22, 2009, 05:01:47 PM
Hey, I just got my board in and had  question. If you look at the image of the PCB Taylor posted in the Gristleizer PCBs for sale thread;
(http://img27.imageshack.us/img27/228/gristleizerpcbimage.jpg)

you can see a lot of small holes. There is one between the 47K and 470K resistors to the right of the TLO72 and one that would be under the 47K resistor left of pin 3 of the TLO72. What are these for? Sorry if there is a really obvious answer here, are they jumpers or what?

Thanks!

All they do is allow for the traces to run between the bottom and top side of the board. 
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: svstee on December 22, 2009, 05:15:46 PM
That's good, I was a bit worried. So I don't have to do anything with them, correct? Apologies, I'm kinda new to PCB's... Vero forever!  :icon_twisted:
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: frequencycentral on December 22, 2009, 05:35:51 PM
PERF forever!  :icon_twisted:
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on December 22, 2009, 05:45:37 PM
So I don't have to do anything with them, correct?

Correct, as mentioned, they are just little wormholes that bridge the 2 sides of copper. Nothing goes in them.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: svstee on December 22, 2009, 07:20:23 PM
PERF forever!  :icon_twisted:

Somehow I expected that, fanboy.   ;D :icon_rolleyes:
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Roy on December 24, 2009, 06:05:49 AM
I've got my two boards (thanks Taylor) and I plan to put one together completely standard as a reference, and then if there's anything I think could be better I'll put those mods onto the other.

Im sure this is really obvious if I just looked properly, but where is the schematic? I was looking for how exactly the MAX1044 was wired up (this doesn't feature in the original) and a pin list for the ten way connector. Also the connections marked 1234 in the top right, and where are the grounds for the input and output taken from? The optional capacitor - what does that do?

It's a very compact board. I like small.


Roy Gwinn
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on December 24, 2009, 08:19:28 AM
Roy,

Have you checked out the PDF project file? It has a wiring diagram and full schematic--check out the first post--it's linked there :)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Roy on December 24, 2009, 12:02:01 PM
Thanks Josh, I've got it now.

http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=41718 (http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=41718)

That optional capacitor isn't mentioned on the schematic. Tracing, it is between the DEPTH wiper and ground, so rounding off the edges of the modulation waveform. That's what the (rather poorly designed) low pass filter R15/C5 and R16/C6 was supposed to do. I shall have a good look at this and see if I can come up with something better.

Roy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on December 24, 2009, 02:12:24 PM
Sorry about that Roy; since your boards were gratis, you didn't show up in my Paypal list of people to send the link to.

I'll have to add that cap to the schematic, you're right.

There is only one ground on the board, this follows the convention I've been using that the ground from the board, the output jack, and the power jack should all be tied to the input jack ground tab. This is start grounding, and while I'm not certain if it's really necessary for pedals, it does seem to be the common convention these days.

Looking forward to your thoughts.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: svstee on December 24, 2009, 02:38:15 PM
This is start grounding,

Is that similar to making something jumberable?

Sorry, I had to... ::)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on December 24, 2009, 07:41:33 PM
(http://www.impalerthemovie.com/yahoo_site_admin/assets/images/Jeez-not_agaian.136173852.jpg)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on December 26, 2009, 09:03:44 PM
OK, well no real joy on the ticking front.
Small value nF and pF caps have some effect on certain settings in the optional cap spot.
Shielding Out/Input was not successful, and I don't think there is any point shielding anything else.
I've built the "fast and not so dirty sine generator" on the breadboard and set the triangle wave with my little scope. I'm getting  a small amplitude on a small screen (JYE Tech 50 dollar scope) so it's not super precise, but my big scope has blown a tiny fuse that I'm having trouble sourcing.
The single biggest improvement has been ripping the LED out completely, after trying several different substitutes.
I've checked the orientation of transistors and FET.
On a whim I changed out TLO72 for TLO62 and I think I got a slight reduction in tick, although my limited understanding of this circuit suggests that it is not logical.
I may begin to change out the rest of the IC's,transistors and Fet, but as both effect and all controls are functioning correctly it's a bit redundant.
I've spent the last four hours reading about decoupling, I'm wondering if I can get anything useful out of splitting TL074 back into two Opamps with further decoupling, but I'm a bit out of my depth here, so I would appreciate any suggestions.
It's still a useful effect with useable settings, but the tick is getting on my nerves :icon_mrgreen:
Love to hear about any other builds
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: oldschoolanalog on December 27, 2009, 01:38:28 AM
Hey Aston,
Just finished mine. Same ticky problem as you have. I tried a few things and this seems to have promise:
Take a fairly large electrolytic cap; I tried 330uf; and touch it to pins 4 & 11 of the TL074 (I used a 33174). Take care to mind correct polarity and not to short anything.
In initial tests this seemed to eliminate the ticking. This was done at low volume without any input signal, so obviously more testing needs to be done.
I got this idea from here:
http://sound.westhost.com/dwopa.htm
The bypassing section. Figure B.
More testing tomm. when I don't have to have things at a whisper volume...
Hope some of this helps.
Dave
PS: There has to be a less "brute force" way to do this, but this is a start.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on December 27, 2009, 08:32:38 AM
Thanks Dave, I already tried the cap trick on pins 4 and 11, but with only a 100uF, I'll try again.
Flo and J.C. gave some interesting advice in this thread
http://www.diystompboxes.com/smfforum/index.php?topic=69638.40 (http://www.diystompboxes.com/smfforum/index.php?topic=69638.40)
But in order to decouple more it seems like I'll have to break the quad up, I don't understand this circuit well enough to be able to say what the different sections of the quad are doing so I can see if I need a double and a single or 3 singles.
Hopefully there will be a much more elegant solution :icon_rolleyes:
I'll post back if the cap has the desired effect. Thanks
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on December 27, 2009, 09:25:22 AM
Ok I tried the 330 cap without success, I guess I will bend pins 4 and 11 of the 74 up and try to implement that design you linked to on ESP.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: oldschoolanalog on December 27, 2009, 10:16:59 AM
Just tried mine at a "normal" (fairly loud :icon_lol:) volume. The ticking is barely noticeable. You really have to turn things up and listen carefully to hear it. I'll check out some of the ideas in the thread you mentioned (Thanks!) and report back later.
Have you tried any other op amps in place of the 074? Maybe try something w/lower current consumption; LM324, TL064, MC33174, etc.
Nice little effect. BTW, I got a much better response using a C100k for the bias pot.
More later...
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on December 27, 2009, 12:14:48 PM
Yeah I think the low power consumption quad is the way to go, unfortunately the only other quad I have at the moment is a RC4136N, which apart from the different pinout is (if I am looking the right place in the datasheet) higher consumption.
You used the MC33174  so if it's got to be ordered I'll go with what is working :icon_biggrin:
Great to hear there is a solution. The bias pot is also interesting to get a confirmation on, but again I only have a 50k or 500k in stock :icon_frown:, perhaps I'll try the 500k for the sake of experimentation.
Do you know if two dual Opamps are generally higher consumption than an equivalent quad, I may try to gerry rig something on the breadboard with two TLO62's and some of the decoupling you linked to.
Thanks for your help, glad you got it sorted out.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: oldschoolanalog on December 27, 2009, 01:25:14 PM
Don't go ordering MC33174's just yet; they are kind of expensive (traded w/a friend for mine). It was the first low current quad I had handy. That's why I used it. I have some LM324's (nice & inexpensive) somewhere I'll dig out & try later.
Try putting a tapering resistor on the B100k bias pot (you can just clip it on temporarily) to see if you like the "feel" of a C taper pot.
I tried 10k between lugs 2 & 3, IIRC. I liked it, so the change was made.
Check datasheets for current consumption info.
I wouldn't say it's sorted out completely yet. I still think there has to be a less brute force way to do this.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on December 29, 2009, 04:03:34 PM
I tried the 10k on the bias pot, quite different, it will take some getting used to but in some way the effect now seems to need less bias adjustment between channels, so that could be useful.
81 cents is not going to kill me for the quad you used, but I would be interested to hear about the other options as and when you get a chance. Thanks for the help.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: svstee on January 05, 2010, 12:44:09 AM
Is there a suitable replacement for the 2n3819? I ordered some from Futurlec but they weren't in the package they sent.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on January 05, 2010, 01:49:08 AM
It's mentioned in the PDF:

http://www.aronnelson.com/gallery/main.php/v/Taylor/

I can't remember for sure now, but I think I used a J113. Make sure you doublecheck the pinout if using something else.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: svstee on January 05, 2010, 12:45:19 PM
Bummer, I don't have a J113 either. Could a J201 work if I got the pinout right, or should I just wait for the 2n3819?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on January 05, 2010, 03:13:54 PM
I'm afraid I don't know enough about the necessary qualities in a JFET to work properly here. I believe Roy Gwinn said that any JFET will do, so it's worth trying. I think any one will work, but it may have a narrower band of usable sweep or something. Anyway, it won't hurt anything, so you can certainly try.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: svstee on January 05, 2010, 03:26:11 PM
Well, I just got an email from Futurlec:

Dear Sean
 
Our apologies for the missing part.    6 of 2N3819s will be resent during today via standard post.
 
 
Should you have any further enquiry, please feel free to contact us.
 
Best Regards
Amp
Futurlec


Might as well just wait, although I was really looking forward to boxing this thing up...
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on January 05, 2010, 03:28:26 PM
socket that sucker! Don't wait! :)

Once I (finally) get around to building my 2nd one, I'm going to spend some extra development time with it--one of the things I'll be testing will be the Jfet. I'm going to test a few types, and hopefully yield some results on what other options exist.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: svstee on January 05, 2010, 03:39:32 PM
Urgh, I HATE socketing transistors. Always falling out and bumping into other stuff, but I might break my rule this one time. Those sound samples you posted are twisting my arm on this.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on January 05, 2010, 03:44:35 PM
You could always do the alternative: solder long leads in place of the transistor legs, then run those leads to your breadboard. this allows you to try just about any pinout very easily.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 05, 2010, 04:09:17 PM
Mine is mostly built, I should be ready to test it tonite or tomorrow! Sorry, no pics yet.

So far, no issues, really. Again feeling somewhat iffy about my 2P6T rotary switch wiring, these things confuse the heck out of me.

I used 1N4148, not being able to get 1N34's. This should be no problem, correct?

I visited my folks for a couple of days right before the holiday and my dad had a stack of computer switch boxes of various sizes. Two of them are perfect for pedals, they'll be repurposed for the Gristleizers (building mine in tandem with a friend) for that industrial "repurposed" look- should suit this design, given its history!  :)

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on January 05, 2010, 04:24:57 PM
4148 or 914 will be fine instead of the 1n34 (as noted in the PDF). I used 1n914s on mine. I imagine purists might want germanium, though the difference they'd make is likely to be subtle, if extant.

Is the wiring diagram in the PDF not clear enough? The basic idea is this: the pad marked "1" is the pole for one switch. 2, 3, 4, and 5 are the throws for pole 1. Then the pattern starts over: pad 6 is the second pole, and 7, 8, 9, and 10 are the throws. The throws for the 2 switches should be in the same order as the numbering, so pad 2 should be selected at the same time as pad 7, 3 with 8, 4 with 9, and 5 with 10.

Now, there are 2 different rotary switch types I've come across. The Lorlin type (but this one is an Alpha clone):

Http://www.smallbearelec.com/Detail.bok?no=46

and the open type:

Http://www.smallbearelec.com/Detail.bok?no=117

They do not have the same "pinout" I guess you could call it. The closed/Lorlin type has what seems to me an intuitive arangement - the pole is in the center of the 4 contacts that it touches (this is what is shown in my wiring diagram). But the open type has the pole in between throws 1 and 2. You should take your multimeter to the pins to be sure you understand the arrangement of contacts in your particular switch.

Looking forward to seeing those boxes. You know, even after selling quite a few G-izer PCBs, not a single picture has been made of a finished box. (Even by me...  :()
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 05, 2010, 04:35:23 PM
Uh Oh. I did get the "open" type, the second one, that make and model from Smallbear. I'll see what I can learn from my multi meter with this and probably have to resolder...darn. Although, I have some Lorlin 3P4T's which would work in a pinch, but i assume ignoring one of the poles...?

OK, well I'm glad I asked about that. At the risk of sounding like a total noob, where can I find a tutorial about using a multi meter to identify switch pinouts? (if such a thing exists)

Rotary switches so far have really not been my friends in many projects...

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 05, 2010, 04:36:44 PM
Actually, looking back over my work, I may have done the rotary right. Before I dissassemble that I may power up the module and test it as is to see if I hit the nail on the head (blind luck)

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on January 05, 2010, 04:42:07 PM
that 3p4t will probably serve you best (meaning you won't have any unused positions on the switch), since the user won't see a difference. An unused pole is no big deal.

I think I want to use a 6t again on my next one, but I want to add some crazy 2nd LFO mojo to it that will use those extra positions.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on January 05, 2010, 04:42:43 PM
Actually, looking back over my work, I may have done the rotary right. Before I dissassemble that I may power up the module and test it as is to see if I hit the nail on the head (blind luck)

- Strategy

Haha--at least you'll have sound clips to work with so you know how it's SUPPOSED to sound. I had no clue when I fired it up :)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on January 05, 2010, 05:07:35 PM
Uh Oh. I did get the "open" type, the second one, that make and model from Smallbear. I'll see what I can learn from my multi meter with this and probably have to resolder...darn. Although, I have some Lorlin 3P4T's which would work in a pinch, but i assume ignoring one of the poles...?

OK, well I'm glad I asked about that. At the risk of sounding like a total noob, where can I find a tutorial about using a multi meter to identify switch pinouts? (if such a thing exists)

Well, it depends on your meter. If you have a continuity setting, use that. My meter doesn't have a continuity tester, so I put it on the lowest resistance setting. If there's a connection between the 2 leads, the meter will show some amount of resistance (very small). If there's no connection, it will just say 0 or whatever the display shows when the leads aren't touching anything.

Turn the switch all the way to one side, and pad 1 should be connected to pad 2 (or pad 5), and pad 6 should be connected to pad 7 or 10.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 05, 2010, 06:41:08 PM
Great, I'll verify my work with the continuity tester AND the sound clips!

Thanks guys!!!  :D
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 06, 2010, 02:42:42 AM
 :-\ :-\ :-\ :-\ :-\ :-\

I am really close to being done and pulled up a pad. The wiring on the DPDT switch, pad 1, broke off, so I was doing my usual desolder routine and the whole pad came off  :-[ This has actually never happened to me.

Where else can I take my rewire into the board to make that connection?

ARGGGGGGHHHH

Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on January 06, 2010, 03:08:16 AM
Did the pads on both sides come off? Pad 1 of the DPDT connects to the drain of the JFET.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 06, 2010, 09:55:41 AM
Yeah, both sides...when I desoldered the joint and pulled out what remained of the wire, everything came out  :icon_cry:

I can probably connect this wire to the Drain leg of the transistor socket, though it will be a tight squeeze and fragile. That's the transistor nearest the switch on the layout correct?

Thanks much for the details
Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on January 06, 2010, 10:30:42 AM
Yep, it's the one marked D G S... you want to attach it to D.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 06, 2010, 11:00:44 AM
I hate stuff like this because it introduces an extra layer of error on top of invisible errors...complicating the troubleshooting process  :P

Thanks for your help, should get to this tonite. Then wire the output jack and it's ready to test.
- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on January 06, 2010, 11:29:36 AM
Visible errors are better than invisible IMO.  ;)

But yeah, that's frustrating. I find pro boards like this much easier and less accident prone than homebrew boards, but one thing that's annoying about soldermask is that it makes dealing with this kind of thing, or adding extra components, etc. really hard without any exposed copper. 
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 07, 2010, 01:47:38 AM
 :D Success! I think!

The circuit mostly works even the reaaaaally iffy kludge where I'm wiring the DPDT sw1 wire to the D leg of the JFET. Very dodgy. But, I am getting nice and choppy trem and filter action. I really like the tonality of both. There's ticking, but to me- it's musical. This is a mangle box.

The only thing I'm still not sure about is the 2P6T. A couple of settings on the switch show weak or non existent modulation so I need to see if this is an issue of wrong pinout or just the settings...or maybe I need to tweek the trimpots to get those settings to have action.

I'll listen to jacobyjd's sound samples tomorrow and go from there.

thanks for everyone's help
- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on January 07, 2010, 08:00:46 AM
There are of course 2 switch positions that don't do anything :icon_biggrin:, only 4 throws on each pole are used, but you probably knew that.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on January 07, 2010, 08:26:40 AM
Strategy--one thing you'll have to do is tweak the trimmers for the triangle wave to get it tuned in right. Also, if yours is like mine, the triangle is setting always needs the bias bumped a little hotter anytime you switch from either of the saw or square waves.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 07, 2010, 11:53:17 PM
There are of course 2 switch positions that don't do anything :icon_biggrin:, only 4 throws on each pole are used, but you probably knew that.

I think what I've done is chosen the wrong four so that the 'not do anything' throws are mixed in with 'do stuff' ones. Now to desolder this switch and re do it!  >:(
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 08, 2010, 02:18:38 AM
In the process of rewiring my 2P6T, ALL of the joints on the DPDT broke. I was able to get some of them rewired, but the DPDT pad 4 is totally torn off. I swear, I've never had this much trouble with desoldering a pcb. I'm so bummed  :(

is there somewhere else I can bring that wire back into the board?

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on January 08, 2010, 02:40:20 AM
Yikes! Here's an image of the traces:

http://img97.imageshack.us/i/gristlepcb.jpg/

Don't mind the wonky looking labels, just a weird glitch. The traces are right, though. As you can see, the traces leading to the switches are somewhat serpentine, a result of having to run them all over the place and get them to the edge while keeping the board rather tiny. So, as you can see pad 4 connects to the rightmost 6n8 cap.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 08, 2010, 09:59:10 AM
Thanks Taylor! Strangely enough I was able to re-secure the torn pad (!) back onto the board by sticking a discarded component leg through the hole and soldering the whole assembly together. It's secure on both sides so I wired to that.

I would have to say my only suggestion for any revisions is to make the switch wiring pads bigger, although, now I can see this would add a full centimeter around at least two sides of the pcb if you did the DPDT and the 2P6T pads as bigger sized ones.

The 2P6T switch...there are a couple of settings there that still don't seem to do anything, the settings are all in just a different order now. I think I'm encountering the old, "maybe this is how it's supposed to work and it just seems weird to me but I'll get used to it" category. Now what's a little weirder is that when I'm on triangle wave, the trims don't seem to affect the modulation tuning or if they do it must be very subtle. I'm using 100K bourns trimmers...Did I goof on the value here? What am I looking for on the tuning?

Sorry to have a million troubleshoots on this build, I think the universe is serving me, a counterweight to my year plus of stupidly easy beginners luck on projects that probably should not have been so easy

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on January 08, 2010, 12:27:35 PM
you should hear the changes when you turn the trimmers--from what it seemed to me, you're hacking off the two sides of a square wave...or something. If I had a trimmer in one extreme, it sounded like a sawtooth, in the other, reverse sawtooth.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 08, 2010, 01:51:06 PM
you should hear the changes when you turn the trimmers--from what it seemed to me, you're hacking off the two sides of a square wave...or something. If I had a trimmer in one extreme, it sounded like a sawtooth, in the other, reverse sawtooth.

Interesting. I'm pretty sure that the trimmers are not adjusting the waveform at all. I don't have an oscilloscope which would be handy in this situation. It is possible that these trimmers don't have the right pinout?!? Seems weird though. Again, encountering issues that I've never seen before on this project.

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on January 08, 2010, 01:54:48 PM
What type of trimmers are you using?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 08, 2010, 02:01:11 PM
http://www.mouser.com/Search/ProductDetail.aspx?R=3386X-1-104LFvirtualkey65210000virtualkey652-3386X-1-104LF

100K...

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on January 08, 2010, 02:10:14 PM
I doubt you've got that in wrong, the pin marked 2 in the datasheet should be in the center hole.

Since you've got a 6-position switch, it's going to have 2 setting that don't do anything. Do the other 4 work? I guess you don't have a scope, eh? If you have the ability to interface your music stuff into your computer, there are a couple of good free scope plugins like this one:

http://bram.smartelectronix.com/plugins.php?id=4

It would help to know if what you've got going is right.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 08, 2010, 02:21:59 PM
Taylor, I'll try that scope plugin, that's a good idea. That will be a good test for the trimmers.

I'm not sure what's up with the unused pins on my rotary switch...! Maybe I'll just break down and order one of the more familiar 3P4T, 'closed' style switches

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 08, 2010, 02:23:46 PM
I'll also try to post some video this weekend of running a drone through the pedal and turning the 2P6T...

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on January 08, 2010, 06:08:56 PM
     I can't say that the trimmers on my build had the effect that Josh mentions above. They clearly have a sweet spot, as I remember, it was somewhere close to the middle of each. After tuning using the 500 Hz signal from my 50 dollar scope (beginners luck or good judgement, not sure which) I have pretty much got the ticking under control, though sadly at the expense of the indicator LED. With the LED in the circuit, well ... TICK, TICK, etc. Just waiting for a lower consumption Opamp before I go back and wrap up things. I promise to post pic's when I'm done although I may still be a while, this effect is really a keeper, so I want it to look nice, but although I'm technically OK with materials I'm not much of a graphic artist. It's taking me a while to decide on a design.
      As a reference I went back to Josh's sound clips and compared. Mine sounds very similar I think. Of course the best test would be if Josh built his and A/B tested with the old one, but I guess he has other plans for this.
     As a little aside, I have a tremulous lune on the breadboard adding some buffering and a wet/dry mix + phase shift amongst other things, anyway I found that I could get it to self oscillate in a very synthy way. After enjoying that for a little while a light bulb came on in my head and I grabbed the Gristleizer from the shelf :icon_mrgreen:. This effect is very cool in alot of different contexts. I felt like I had just invented electronic music.
     
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 18, 2010, 11:56:29 AM
Build update:
I swapped out the 2p5t for a 3p4t cannibalized from a dead project. It is definitely less confusing to use this switch, there are fewer weird sounding 'unused' positions.

The triangle wave setting is pretty much not modulating the effect though. I get great square, up ramp and down ramp waves but no triangle whatsoever. I will try to check it out on a scope to see if there's a weak modulation at this setting if any, but I'm thinking there's not. If I can track down which components are responsible for the triangle wave output, I'll see if there's a mistake there: any ideas?

even without the triangle section this is a powerful sound slicing tool, really enjoying it. I want to see if I can trouble shoot that bit before I box it up, any feedback is hugely appreciated!
-strategy

EDIT: to clarify what the triangle setting sounds like, I would say that on VCA, it sounds like unmodulated signal with some very faint ticking. On filter, it sounds like a fixed wah with some very faint ticking. Its clearly going through the circuit and is gained up but, just not being modulated.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on January 18, 2010, 03:04:48 PM
And you've adjusted the trims and bias knob while listening to the triangle? It sounds to me like the bias is set wrong and the triangle is modulating outside the range that does anything. If you can scope it, it makes understanding what's up so much clearer.

But if you've got everything but triangle you're pretty close. If it's not a matter of the pot settings it would just be to do with the Rs and Cs on that switch tap.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 19, 2010, 12:24:20 PM
I've tweeked the trims and bias while on Triangle setting but I need to give it a little bit more rigorous/systematic test this way.

The first thing I'll probably do though is double check my resistor & cap values (and continuity) in line with the switch tap for triangle. What is the best way for figuring this out? ...use my meter to figure out the switch taps, then see what's in the path from there to the IC, right? It is tempting just to reflow solder on anything that looks sketchy, its amazing how touch ups can resolve random issues like this.

DIY has been somewhat trumped the past week and probably until the 30th as a I race to the finish line on my new album which I hope to turn in to kranky by the 30th. Building pedals makes some good procrastination though, this has taken about 3 years and, there's lots of boring stuff like editing audio at this point. Soldering trouble shooting and wiring = great procrastination!

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: thereverend on January 19, 2010, 02:57:24 PM
my futurlec order finally made it into my mailbox. hopefully i'll have this up and running by the weekend.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: svstee on January 21, 2010, 02:46:47 PM
Built mine and got it running. Ran into a few problems, though. Wasn't paying attention and reveresed + and -, cooked the MAX1044. Fixed that and tried again, then noticed I forgot the diodes!

Working now, but it has a few issues:

When I put the Dpdt switch up, it changes the sound like in the clips, but it also makes it REALLY trebly. Think out of lipstick pickups + phase switch + rangemaster treble. Totally unusable.

The Level pot does nothing at all.


Could either of these be because of damage from my earlier mistakes?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on January 21, 2010, 02:58:45 PM
Built mine and got it running. Ran into a few problems, though. Wasn't paying attention and reveresed + and -, cooked the MAX1044. Fixed that and tried again, then noticed I forgot the diodes!

Working now, but it has a few issues:

When I put the Dpdt switch up, it changes the sound like in the clips, but it also makes it REALLY trebly. Think out of lipstick pickups + phase switch + rangemaster treble. Totally unusable.

The Level pot does nothing at all.


Could either of these be because of damage from my earlier mistakes?
I'm assuming you're referring to the VCF mode being trebly. Mine is very treble-heavy as well, but not as bad as yours sounds.

To tame some of that, I roll back the depth control on mine. With depth at minimum, it sounds like a fixed wah. I like mine about half-way.

The extra treble might be tameable with some cap changes.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: svstee on January 21, 2010, 03:23:20 PM
I'll try rolling off the depth. Which caps should I be looking at? I'll probably make it/them switchable.

Any thoughts on the Level pot? Thanks!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on January 21, 2010, 03:30:44 PM
The level pot is really straightforward, just a voltage divider on the output. The only thing I can think is that you've got some bad solder joints.

You don't have both a level trimpot and a level panel pot, right? The level and bias should be either a trim or a panelmount pot, not both.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on January 21, 2010, 03:31:15 PM
I'll try rolling off the depth. Which caps should I be looking at? I'll probably make it/them switchable.

Any thoughts on the Level pot? Thanks!

Can't answer the cap question without some time to look at it, sorry.

However...if your level pot does nothing, there's something wrong. the circuit should have a TON of gain available.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on January 21, 2010, 08:42:27 PM
Quote
You don't have both a level trimpot and a level panel pot, right? The level and bias should be either a trim or a panelmount pot, not both.

Wow, good guess Taylor. I was staring at the schem trying to imagine how it could not work whilst still letting signal through before I saw you'd answered.

I've got some low current consumption opamps now so I'll try them, and make a last attempt to save the indicator LED by changing to an ultrabright with a much higher current limiting resistor. Otherwise I'm very satisfied, tuning with a scope reduced the ticking to almost nothing after the removal of the LED, and that's without any additional caps. Dave told me he also ditched the LED, and he's using the brute force cap mentioned earlier in the thread and has no ticking. Super effect, I'm using it alot.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 21, 2010, 11:46:07 PM
Build report continuation for me:  ;D SUCCESS

I had to mess around w/ the trims a lot before I "found" triangle wave.

Need to add/experiment with LFO out mod now.

wish list mod, low priority for now:
- CV input to LFO speed...possible? or expression pedal input in parallel w/ speed pot? this is above my head for now

Will be a couple weeks before I can put it in enclosure, will post pics when I do.

The pedal sounds great with stage center spring reverb after it, or big cheese before it, haven't tried it yet w/ other pedals yet or with my various keyboards.

Re: ticking, it could have been the eq setting on my mixer, but I could swear that when i did locate the trimpot sweet spot, my ticking reduced slightly. And I'm not using the tick reduction cap. This might be voodoo, I was not systematic about checking this.

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on January 22, 2010, 12:29:37 AM
wish list mod, low priority for now:
- CV input to LFO speed...possible? or expression pedal input in parallel w/ speed pot? this is above my head for now

The Speed pot pans between GND (slowest speed, I think) and -9v. I think doing an expression pedal would involve sending -9v to the pedal, dividing it with the pot inside, and sending the divided voltage to lug 3 of the speed pot (where -9v went before). Make sure you disconnect this lug from the -9v pad. This would actually be series, not parallel, so the panel mounted pot would control the maximum range that the expression pedal could sweep through. Parallel would be like mixing any signals - could be done with a passive mixer.

CV is the same idea, you want to send a negative voltage to lug 3 of the speed pot. I can't really give any more specifics than that because I'm fairly ignorant of what kind of voltages most synth stuff is working around. I think it's usually 0-5v or -5v to 5v, so a CV going down to -9v may not be available in many systems. I guess if you're working with a modular, you can amplify a CV.

Please note that the above is for "sending you in the right direction" of research - I'd suggest you look into these ideas a bit before you try them. Just a little disclaimer so I'm not liable if you fry your board.  :icon_wink:
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on January 22, 2010, 02:46:12 AM
Quote
You don't have both a level trimpot and a level panel pot, right? The level and bias should be either a trim or a panelmount pot, not both.

Wow, good guess Taylor. I was staring at the schem trying to imagine how it could not work whilst still letting signal through before I saw you'd answered.


Looking at this again, it occurred to me that the board does not state explicitly that the level and bias should be either a trim or pot but not both. I never thought to make that clear because it was obvious to me, but it may have tripped some people up. Did anybody else not know that? We haven't heard back from SVStee, so I don't know if that's his problem, but I can't really figure out how sound could be coming out if the level pot doesn't work. Having both level pots in would surely screw things up, though.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: svstee on January 22, 2010, 01:23:26 PM
No, I don't have both a level trim and pot. I thought that one was obvious too, Taylor. I didn't check the pot, there must be a fixed resistance. Thats the only way I could see it working the way it does.

Any idea what caps I should be looking at to tame treble?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on January 22, 2010, 01:29:03 PM
Build report continuation for me:  ;D SUCCESS

Fantastic, man! Once calibrated, it's a really solid effect :)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on January 25, 2010, 03:00:35 PM
OK, so having done this to another effect recently, I would say a prime mod for this pedal is expression pedal to LFO rate. Using one of those 6-pin Neutrik stereo switching jacks. I'm out of those but will post a mod pic when i do it.

The great thing is this is a 10K pot and most expression pedals are 10K meaning you should get the full range sweep with pretty much whatever you put in there.

This is easier than implementing CV to LFO rate for sure, and gives you the ability to speed up that LFO without having to reach a hand away from your guitar to turn the knob...

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on January 25, 2010, 03:42:55 PM
Just to get my thoughts down on mods (and maybe so someone who's farther along can do some leg-work for me  :icon_cool:), here's what I'd like to try:

-Expression for LFO speed would be nice, as Strategy mentioned
-Some sort of filter range controls--a lot of us have experienced that it's mainly at the treble-heavy end of things. I'd like to be able to...swap sweep caps maybe (a la a Crybaby sweep switch)
-Additional LFO(s)--for modulating the main LFO, or other dastardly possibilities.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on January 25, 2010, 04:28:35 PM
There are 3 ways to do a speed exp. pedal. The really easy way is to just use a plastic switching jack that subs the exp. pot in where the speed pot was in the circuit. This disables the panel speed pot. You need to use a plastic one so the sleeve doesn't ground out to the enclosure.

Then there's the series way I mentioned a few posts back. This brings the speed pot control into play but only to limit the max sweep of the exp. pedal, which if you're using a Moog exp. pedal (my favorite) you've already got this built into it.

The third is parallel, where the panel speed pot and exp. speed pot are totally democratic. This involves sending the voltage to both of them separately, dividing it with the pots, and mixing the 2 voltages together with a resistive mixer.

Extra LFOs would be fun. Another neat thing you could do that would be a little easier would be to take the LFO out, send it into a delay pedal, and run it to its own voltage control input. So the delayed LFO could control its own speed. This is the kind of wacky stuff that's fun to do with modular synths.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: disorder on February 02, 2010, 11:29:20 AM
just wondering if anyone actually fit this in a 1590bb. I see the board fits fine but the additional rotary switch, dpdt switch, and bypass switch it might be cutting it close.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on February 02, 2010, 02:07:42 PM
I haven't boxed it yet, but I think it should be fine.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 02, 2010, 02:11:20 PM
I built mine in a BB. It fits fine, depending on how you orient the pots.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on February 04, 2010, 10:13:30 PM
Anyone try expression pedal input yet? I put one on my LFO rate pot today - a 6-pin stereo neutrik (plastic body) so that when I insert the pedal it should disconnect the pot. Not working though. pot controls LFO rate when nothings plugged into the jack, then as soon as I insert the expression pedal it disables the LFO altogether. Ideas?

should I post a pic perhaps? ???

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 04, 2010, 10:32:11 PM
You probably have the jack wired wrong for your expression pedal. They're all different. If you're using a Moog, the positive and negative should go to the sleeve and the ring, and the divided voltage should go to the tip. You may need to bust open your exp. pedal to check how the pot is connected to the jack.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on February 04, 2010, 11:43:55 PM
Taylor

You may be right but I took a couple hours off from working on it and lo and behold I think I see the problem- I put the jack on such that the two pots connect together when inserted but, the connection to the board is then broken. I'm going to turn the jack the other way, re wire it and see if that works!!

Failing that I'll try your suggestion!

Its amazing what some food/coffee/stepping away will do for trouble shooting  :P

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 04, 2010, 11:51:38 PM
Yeah, I find invariably that once I've lost hope, and come back to it an hour later, it's something facepalmingly obvious. Though in my case I suspect the coffee may be the cause of the problem, not the solution - too much of it, specifically.

I only said that because I built something expression-controllable for somebody and when he got it the expression didn't work at all, even though it worked fine for me. Found out that the connections and pots inside expression pedals have no standard or correlation with each other.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on February 05, 2010, 12:11:17 AM
this could still be an issue- not the coffee, but the non-standardness of expression pedals. This is a Roland EV-5.. I now have control over the LFO rate via pedal, BUT, it's erratic. To complicate matters, the pedal pot is connected to yet another pot that attenuates the range of the pedal. I'm confused by what I see inside this thing.

Symptomatically, the largest sweep range brings the pedal into some pop-snap no-sound-at-all territory with the pedal rocked all the way back, then goes slow to fast, faster and then...SLOWER again!  :icon_eek:

I tried a "peep" photocell passive controller thing and, it's cool but doesn't get it very slow...the variable resistance may not be equivalent to 10K. But that's a start.

Will keep prodding at this...

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on February 05, 2010, 01:17:26 AM
I can't seem to make it work...well, it's still a kick ass pedal! If anyone comes up with a replicable scheme for exp pedal input using a 'known quantity' pedal like the Moog, and can sketch a quick diagram of it, I'll try again later. Now to try the LFO out mod!

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on February 05, 2010, 02:06:34 AM
LFO OUTPUT MOD is a success! using the + pad of the optional electrolytic cap as Taylor outlined in the documentation.

Depth attenuates the LFO output which is great, meaning no attenuator needs to be added. Was a little extreme going into my Memory Boy CV input, but sounded great on my Doepfer filter module. LFO output is active even when pedal effect is bypassed, which is great too.

OK, pics on Saturday of the final product.

Thanks to all who helped me with this fun project and thanks to Taylor for the layout and pcb run!

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 05, 2010, 02:25:40 AM
Are you using the Moog exp. pedal? If so, I can draw up a diagram of how it should work tomorrow.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on February 05, 2010, 10:59:54 AM
@Taylor, no, I'm using a Roland pedal, but, I will probably get a Moog pedal because I need more expression pedals and the music stores around here (and Craigslist) have pretty good amounts of these almost all the time...and I need more expression pedals.

Thanks for the diagram!

I spent a long time last nite running Weird Sound Generator through Gristleizer, then Stage Center Reverb, then Memory Boy with the delay time modulated by the Gristle LFO. Pretty killer sounding...creepy crawly warbly synth noise music sounding like the first Cluster album or something.

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on February 07, 2010, 12:43:04 AM
GRISTLEIZER BUILD PIX!

A team of experts was deployed to investigate the Gristleizer build.

(http://farm3.static.flickr.com/2723/4336147385_acefc6dfb1_o.jpg)
(http://farm3.static.flickr.com/2608/4336893426_ec6d3d80a5_o.jpg)

FINDINGS
- LFO output during initial testing seemed fine with Memory Boy and Doepfer module CV inputs, but today when in use, the normal effect seemed to 'dim' in voltage when the LFO CV output was used. Further testing must be done to see if this mod causes some kind of voltage hogging/starve side effect.

- Enclosure from 1990s computer peripherals and mystery surplus rate knob appear to be 100% resistant to sharp ferret chomp attempts

- Janky hand drilling resulted in slightly off kilter LED alignment

- Effect sounds great all around and was a fun build with room for more mod experimentationbv


(http://farm3.static.flickr.com/2697/4336893584_08fecb40a4_o.jpg)




Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 07, 2010, 12:48:27 AM
Hey, really cool. :) Finally a post about electronics my girlfriend will care about - it has tiny furry creatures in it.

That knob is boss, I am a bit of a vintage knob fan.

Need to get on that diagram... firing up MSPaint...
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on February 07, 2010, 11:54:23 AM
Nice enclosure, good job. I like the AB switch for output to Flatscreen or printer, can you post those mods :icon_biggrin:
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: skweeegor on February 10, 2010, 07:10:35 PM
This pedal will be my first self sourcing/non kit adventure, and I've got a really noobish, ignorant question here. I see that this pedal takes 9V and I've seen people mentioning that they've built power supplies for them. Can it not just be powered with a 9v dc wallwart or is there something wrong with that picture that I'm missing?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 10, 2010, 07:20:40 PM
The Gristleizer needs to run on a bipolar power supply, which means both positive 9v and negative 9v. But my PCB has a built in voltage converter section, so you feed it a regular old +9v supply and it sends negative 9 volts to the parts of the circuit that need it.

So you don't need to build a separate power supply for this PCB, those comments would be regarding some older PCB without the built-in charge pump.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: skweeegor on February 10, 2010, 07:23:54 PM
Awesome, thanks.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 10, 2010, 08:43:43 PM
BTW, it's not a noobish question at all (and those are fine anyway). The vast majority of guitar effects run on a single-sided supply.

I would actually be interested to know why this circuit was designed with a bipolar supply. Usually this is to increase headroom, but to my ears the Gristleizer has very low headroom - the opamps distort quite readily (though I use a bass with a built in preamp, so the output is hot). This means that, using a single 9v supply, the circuit would be even more distorted, but I don't really understand why it's like that.

The gain of the first stage is 11, which I guess is kind of a lot. Seems like maybe different values could be chosen for the resistors around IC1/1 to cut this down a bit. Just thinking out loud here...
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: skweeegor on February 10, 2010, 08:48:12 PM
Yeah, the fact that all the other effects I've used/built didn't require their own supplies confused me a bit. Generally I'd go with the "try it and see" method for any unknowns but that's not the best idea when power is concerned.

Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: kelmark on February 10, 2010, 09:57:19 PM
Hi fellow builders,

I'm building up the Gristleizer from Taylor's PCB :icon_biggrin: :icon_biggrin: :icon_biggrin:, and I'm having trouble laying my hands on the 470uf Cap from my substantial component supply and my local parts store, the only 470uf caps I can find locally is: a. dipped Tantalum (which is polarized) or b. 470uf radial Electrolytic Cap. So my question is this;  can I use either of these above caps  and if so how should I wire them in given that they are polarized, or should I keep looking for one on-line or should I wire couple 220uf ceramic cap in series and be done with it. Or am I missing something obvious here. Any advice will be appreciated :icon_biggrin:

And BIG Thanks to Taylor for suppling the PCB on this wonderful project! ;D

Kelmark
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on February 10, 2010, 10:10:17 PM
The electrolytic is what you want--you'll have to check the schematic for the polarity--it should be noted there.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 10, 2010, 10:38:17 PM
Hi fellow builders,

I'm building up the Gristleizer from Taylor's PCB :icon_biggrin: :icon_biggrin: :icon_biggrin:, and I'm having trouble laying my hands on the 470uf Cap from my substantial component supply and my local parts store, the only 470uf caps I can find locally is: a. dipped Tantalum (which is polarized) or b. 470uf radial Electrolytic Cap. So my question is this;  can I use either of these above caps  and if so how should I wire them in given that they are polarized, or should I keep looking for one on-line or should I wire couple 220uf ceramic cap in series and be done with it. Or am I missing something obvious here. Any advice will be appreciated :icon_biggrin:

And BIG Thanks to Taylor for suppling the PCB on this wonderful project! ;D

Kelmark

There aren't any 470uf caps in the G-izer. There is a 470nf, though, which is the same as .47uf. I don't like to use values with decimals on the PCBs because sometimes people don't see the period.

So what you need is a .47uf, which is more properly written as .47f, or 470nf.

uf/f=microfarad
nf=nanofarad
pf=picofarad

1uf/f = 1,000 nf = 1,000,000pf.

Hope that helps!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: kelmark on February 10, 2010, 10:59:17 PM
Hi fellow builders,

I'm building up the Gristleizer from Taylor's PCB :icon_biggrin: :icon_biggrin: :icon_biggrin:, and I'm having trouble laying my hands on the 470uf Cap from my substantial component supply and my local parts store, the only 470uf caps I can find locally is: a. dipped Tantalum (which is polarized) or b. 470uf radial Electrolytic Cap. So my question is this;  can I use either of these above caps  and if so how should I wire them in given that they are polarized, or should I keep looking for one on-line or should I wire couple 220uf ceramic cap in series and be done with it. Or am I missing something obvious here. Any advice will be appreciated :icon_biggrin:

And BIG Thanks to Taylor for suppling the PCB on this wonderful project! ;D

Kelmark

There aren't any 470uf caps in the G-izer. There is a 470nf, though, which is the same as .47uf. I don't like to use values with decimals on the PCBs because sometimes people don't see the period.

So what you need is a .47uf, which is more properly written as .47f, or 470nf.

uf/f=microfarad
nf=nanofarad
pf=picofarad

1uf/f = 1,000 nf = 1,000,000pf.

Hope that helps!

I'm sorry I meant the .47uf cap that is labeled  470nf on the pcb.  Is this a electrolytic? if so how is it orientated? Caps kinda screw it my head anyway... Thanks for the help!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 10, 2010, 11:25:14 PM
I used a boxed metal film cap, like so:

http://rocky.digikey.com/weblib/Panasonic/Web%20Photos/New%20Photos/ECQ-UV%20SERIES%2015.0H,17.5L.jpg

I generally use these for anything smaller than 1uf, electrolytics for bigger than 1uf, and ceramic for really small values like 27pf.

Definitely don't use an electrolytic there, any kind of film or ceramic cap is ok if you can't get the boxed film caps.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Derringer on February 11, 2010, 09:40:51 AM
Would running the flashing LED through the main stompswitch so that it doubles as an off/on indicator be bad procedure?

It would most likely cause a nasty pop because of the current rush right?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on February 11, 2010, 09:50:31 AM
Ok--I finally started to look over this board for my second Gristleizer build--I'm still a Futurlec order away from all the parts I'll need (haha), but I might as well start planning now.

Here are my build constraints:

1. I'm going to fit this into a 1590B. Yeah, you heard that right.

2. Because of condition (1), I'm going to have to work around that whole rotary switch problem by using an on-off-on dpdt for the LFO switch, omitting 1 of the LFO shapes (It'll probably be the rev. sawtooth).

That's pretty much it. Because of the board-mounted pots, I'll be able to pull this off, I'm pretty sure. I still need to check my measurements. I may also have to go with a DPDT and a buffered bypass, OR a millennium setup on a daughter board. I'll ring in with other issues as I work on the project.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on February 11, 2010, 01:12:45 PM
You *might* be able to keep your switch profile low without sacrificing an LFO waveshape setting. I couldn't see any toggles with enough poles/throws (though I think they do exist) on Mouser just doing a quick browse, but there's also slide switches. Of course this gets into 'new part' territory- figuring out pinouts, how to mount in enclosure, etc'- maybe this isn't super helpful, but something to consider...

- Strategy

EDIT: I meant to include this link...http://www.mouser.com/Electromechanical/Switches/Slide-Switches/_/N-5g2x?Keyword=3+pole+switch&FS=True

Just a selection of slide switches...

Ok--I finally started to look over this board for my second Gristleizer build--I'm still a Futurlec order away from all the parts I'll need (haha), but I might as well start planning now.

Here are my build constraints:

1. I'm going to fit this into a 1590B. Yeah, you heard that right.

2. Because of condition (1), I'm going to have to work around that whole rotary switch problem by using an on-off-on dpdt for the LFO switch, omitting 1 of the LFO shapes (It'll probably be the rev. sawtooth).

That's pretty much it. Because of the board-mounted pots, I'll be able to pull this off, I'm pretty sure. I still need to check my measurements. I may also have to go with a DPDT and a buffered bypass, OR a millennium setup on a daughter board. I'll ring in with other issues as I work on the project.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on February 11, 2010, 01:21:38 PM
A followup to my LFO output mod: I can see what is happening with the LFO output. When a cable is inserted into the LFO output the LFO is not injecting as much voltage into the circuit. Effectively bringing it to the front panel means sacrificing LFO depth of the LFO signal.

If anyone can suggest a way to possibly prevent/circumvent this, that is great- my understanding of electronics is probably too elementary to brainstorm a way around this issue...

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 11, 2010, 01:28:42 PM
A followup to my LFO output mod: I can see what is happening with the LFO output. When a cable is inserted into the LFO output the LFO is not injecting as much voltage into the circuit. Effectively bringing it to the front panel means sacrificing LFO depth of the LFO signal.

If anyone can suggest a way to possibly prevent/circumvent this, that is great- my understanding of electronics is probably too elementary to brainstorm a way around this issue...

- Strategy

You could add another dual opamp to buffer and amplify the LFO signal. Try non-inverting opamp amplifiers:

http://www.play-hookey.com/analog/non-inverting_amplifier.html

Here you can calculate the gain you need:

http://tangentsoft.net/audio/calc.html

Or you can make the 2 resistors the 2 sides of a pot and you can have variable gain.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on February 11, 2010, 02:17:25 PM
thanks Taylor, I suspected I'd have to add a buffering feature like this- a good experiment!
- STrategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 11, 2010, 03:01:33 PM
Would running the flashing LED through the main stompswitch so that it doubles as an off/on indicator be bad procedure?

It would most likely cause a nasty pop because of the current rush right?

This would be a good idea. I think I mentioned it in the other thread. I don't really think there would be a pop, at least no more than the usual LED switching arrangement.

Ok--I finally started to look over this board for my second Gristleizer build--I'm still a Futurlec order away from all the parts I'll need (haha), but I might as well start planning now.

Here are my build constraints:

1. I'm going to fit this into a 1590B. Yeah, you heard that right.

2. Because of condition (1), I'm going to have to work around that whole rotary switch problem by using an on-off-on dpdt for the LFO switch, omitting 1 of the LFO shapes (It'll probably be the rev. sawtooth).

That's pretty much it. Because of the board-mounted pots, I'll be able to pull this off, I'm pretty sure. I still need to check my measurements. I may also have to go with a DPDT and a buffered bypass, OR a millennium setup on a daughter board. I'll ring in with other issues as I work on the project.

Josh, I don't know if you've considered this, but there are some very low profile rotary switches that are meant to be surface mounted. They have very thin bodies, and I think they're available in 3P4T. If that interests you I can bust out the Mouser catalog and give you some part numbers. The only thing is that they often don't have mounting hardware, since they're not meant for panel mounting, so you'd have to epoxy it to the case.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on February 11, 2010, 03:04:47 PM
Thanks for the suggestion, Taylor--I'm going to stick with either the toggle or slide idea--I don't really use all the wave shapes anyway. If I have to scale back to 2 (Square and Triangle), then I can live with that. I'd really like to fiddle with an on-off-on wiring scheme to squeeze 3 out of it though--I'll see what I can come up with :)

I'm still planning on building a 3rd that has all the features and more in a few months :)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 11, 2010, 05:42:41 PM
I can't seem to make it work...well, it's still a kick ass pedal! If anyone comes up with a replicable scheme for exp pedal input using a 'known quantity' pedal like the Moog, and can sketch a quick diagram of it, I'll try again later. Now to try the LFO out mod!

- Strategy

(http://img689.imageshack.us/img689/8049/gizerspeedexp.png)

This should work.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on February 11, 2010, 05:49:19 PM
I'll try it soon Taylor, thanks a million!

the oval shaped end of the switching jack in your drawing represents the insert end of the jack, correct?

Now off to order some more switching jacks and pick up a Moog expression pedal!

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 11, 2010, 06:09:35 PM

the oval shaped end of the switching jack in your drawing represents the insert end of the jack, correct?

- Strategy

Yep.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Derringer on February 15, 2010, 04:30:30 PM
some clips of my first start-up

http://www.zshare.net/audio/72611071428208bc/

http://www.zshare.net/audio/72611110edfa8704/

It fired right up for me. There's some tic, even when bypassed, but not enough to irritate me. I play noisy rock music anyway so a little sputter is no big deal.

I put it on the scope and had trouble making a triangle wave.
What selection should I have the rotary switch on for the triangle? Yeah I know ... put it on the triangle selection ... but  which selection is that?

As a tremolo this thing is sick, and a flip of the vca/vcf switch sends the sounds into orbit!

I'll post some pics as soon as I figure out how to get my laptop to upload them ... it's balking everywhere, gmail, photobucket, imageshack etc ... just flat out refuses to upload.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on February 15, 2010, 04:44:03 PM
some clips of my first start-up

http://www.zshare.net/audio/72611071428208bc/

http://www.zshare.net/audio/72611110edfa8704/

It fired right up for me. There's some tic, even when bypassed, but not enough to irritate me. I play noisy rock music anyway so a little sputter is no big deal.

I put it on the scope and had trouble making a triangle wave.
What selection should I have the rotary switch on for the triangle? Yeah I know ... put it on the triangle selection ... but  which selection is that?

As a tremolo this thing is sick, and a flip of the vca/vcf switch sends the sounds into orbit!

I'll post some pics as soon as I figure out how to get my laptop to upload them ... it's balking everywhere, gmail, photobucket, imageshack etc ... just flat out refuses to upload.

I think the triangle is the 2nd position, IIRC.

But...wtf is going on with yours--it sounds like you've got BOTH VCA and VCF going on there. I'm hearing tremolo and filter going at the same time. I want that.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Derringer on February 15, 2010, 04:51:36 PM
I've got the bias and depth cranked up, but not all the way, there are sweet spots on both knobs

at points during the clips I'm hitting an octave up before the gristleizer and delay after it

But yeah dude, I don't know if mine is 100% "right" but I dig

thanks for the kind words :)

and thanks for the info on the rotary
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 15, 2010, 05:00:02 PM
Hmm, it does sound like trem and filter at the same time. I think maybe what's happening is that the LFO has a really large sweep and it's cutting between the area where it's audible and then "outside" the proper range. When it cuts outside the range of audibility it kills the signal which creates a tremolo in sync with the VCF.

That, or you built it "wrong" and it sounds better that way.  :)

I think it's a matter of how the LFO is set: I'm guessing that those sounds are available somewhere in the tweaking of the trimpots. I need to go mess with mine a little more. I have to confess that I haven't fired it up since the day I built it to verify the PCB. Aside from the weird sounds, which are great, I think the G-izer makes for one of the best tremolos I've ever used. That FET gives it a precise feeling of control that you don't get with an opto-based trem.

Awesome clips, Derringer!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on February 15, 2010, 05:13:05 PM
Quote
But...wtf is going on with yours--it sounds like you've got BOTH VCA and VCF going on there. I'm hearing tremolo and filter going at the same time. I want that.
+1
Can you find out what you did "wrong" so we can all do it :icon_mrgreen:
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Derringer on February 15, 2010, 05:59:56 PM
I'm very confident that all the wiring and components are correct. I really took my time with it.

play with the shape and offset trims. I really didn't do much with them. Before I plugged a guitar into it, I ran a 1Khz sine in and scoped it on the output. I tried to get a triangle wave, but couldn't so just left that pot randomly adjusted, same with the offset. Now at that time, I also didn't know where to have to rotary pot set.

so ... just play with it. Start by turning the bias up till the sound gets loud and distorted. This is pretty high up on the bias pot. Bring the level down to compensate. Then, turn up the depth pot till you can hear some 'squawk' happening. 
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 15, 2010, 06:05:30 PM
You should be looking at the LFO waveform on the scope (tap it from the + pad of the "optional 10uf" cap), rather than the output, to see a triangle. The output isn't ever going to look like a triangle using a sine wave input.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Derringer on February 15, 2010, 06:40:45 PM
ok, this part is over my head right now

should I still send a sine wave into the circuit?

I have the optional 10uf cap installed, I should still be able to tap off the + side right?

do I need to adjust my scope from how I currently have it set (to read a 1kHz sine) to read the lfo waveform?

thanks
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 15, 2010, 07:00:05 PM
Well, first, it could be that your mis-adjusted waveshape control is what's giving that nice sound, so it's up to you whether you feel you need to tweak it any further. If it ain't broke...

I don't know what kind of scope you're using, and I'm not experienced with anything but my cheapo digital scope. But you don't need to send a signal at all into the circuit. What you're looking at when tweaking the waveform is the LFO, which is a free-running oscillator that's going all the time, even without any signal input to the circuit. You might need to set your scope for DC coupling to see the LFO properly.

Yes, you should be able to see it even with the optional cap installed. You can see the signal at the center lug of the Depth knob as well. So that's the LFO, and that's what should look like a triangle in one of the switch positions (which one is triangle actually depends on which way you read the wiring diagram when you wired it - you can look at the switch as if it's drawn from the bottom or the top - both will work the same, just with different positions for the different waveforms).

It should look like a square wave, a ramp wave going up, a ramp wave going down, and then the last wave that isn't one of these three is supposed to look like a triangle, but it probably won't when you first look at it.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Derringer on February 15, 2010, 07:17:52 PM
I fiddled with the scope a bit with no luck, so I tried the tune-by-ear method and I think I got it. I definitely found which rotary position is affected by shape trim.

Overall sound is still pretty much the same. I'll fiddle some more with the scope tomorrow and see if I can get it that way too.

thanks
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 15, 2010, 07:20:07 PM
If you had the scope setup to look at audio frequencies, you'll need to turn the time scale on the scope slower to see the LFO.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Derringer on February 15, 2010, 07:32:14 PM
that would probably be the "sweep time/cm" adjustment then ... cool
thx


and pics
(http://i215.photobucket.com/albums/cc241/guyatron/grist1.jpg)
(http://i215.photobucket.com/albums/cc241/guyatron/IMG_0152_1.jpg)
(http://i215.photobucket.com/albums/cc241/guyatron/IMG_0154_1.jpg)

not my neatest build, but there's nothing shorting out and the lid closes easily
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Ry on February 15, 2010, 08:12:48 PM
Got mine running this weekend  ;D.  What a beast, this is a great pedal, much more fun than I imagined it would be.  I love how dirty it can get with the bias knob tweaked.

This one will get a spot on the pedalboard!

Thanks to everyone involved!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on February 22, 2010, 02:01:44 AM
Gristleizer got a test run at band practice today. AWESOME...I used this on farfisa organ and it was REALLY complementary with keyboards. In fact, I would say some of the clipping I got on hitting guitar chords pretty loud- sort of not an issue with the organ, which is dynamics-free. Rich chords and drones sound awesome through it.

We recorded but the takes aren't in the band FTP yet, when they are I'll try to isolate a little snippet and post it here.

- Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 22, 2010, 03:32:33 AM
Cool, I don't have my Farfisa anymore, but it's a fun and peculiar instrument. They have a very distinct sound, more rich than the goofy console organs with built-in rhythms, but still a little goofier than a Hammond. A Farfisa through the Gristleizer is a neat idea indeed. I'll be interested to hear that.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on February 22, 2010, 08:18:11 AM
I put an order in last week for parts for 3 of these babies--we'll see what I can come up with :) Working on my box layouts now.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on February 23, 2010, 07:24:14 PM
I've had my farfisa for almost 20 years (woh that makes me feel old...I'm going to be 34 this year) and it's been in almost all my bands. Pretty stoked. What's weird about Gristleizer is...The filter sounds like a PHASER. Or very phase like in character, as though it is sweeping within a similar range to some popular phasers. I can't get more scientific than that, though.

Weird observation in the ongoing testing process is that ticking seems dependent on input and output gear. I had my guitarist test the gristleizer with his Sunn/Orange 4x12 setup. The ticking was really loud. On organ and played through a Fender DeVille clean channel the ticking was totally undetectable. Really weird. I keep thinking I will add the de-ticking cap, but every other time I use the thing the ticking seems more or less apparent and I can't really nail it down.

- Strategy

Cool, I don't have my Farfisa anymore, but it's a fun and peculiar instrument. They have a very distinct sound, more rich than the goofy console organs with built-in rhythms, but still a little goofier than a Hammond. A Farfisa through the Gristleizer is a neat idea indeed. I'll be interested to hear that.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: thedefog on February 26, 2010, 11:00:26 PM
I'm posting on this thread since the other one I was posting to is a little dated (dec 27th).

I built my Gristileizer using the board that jacobyjd used in his initial post. At first I was having issues with the lfo speed. It was not getting slow enough (averaged a sweep around 1/2 a second at lowest settings). I remedied this by placing a 680k resistor at the input. Now I get a very slow sweep, which sounds like the other demos I've heard.

Currently, I'm trying to remedy the excess distortion in the circuit created. I'm assuming that it is the nature of the effect, but I'm not entirely certain. I've tried different resistor values on the initial input opamp, as well as the output opamp, but due to the other values in the circuit it doesn't function properly when I change the gain factor. I don't really know enough to figure out what is necessary to lower the overall output without adversely changing the way the circuit functions. Does anyone have any thought on this one?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on March 08, 2010, 10:32:25 AM
This weekend I populated my Gristleizer board (this is to be build #2 of 4). Still have to solder it all together. However, I wanted to post my 1590BB layout mockup for everyone to check out. :)

(http://i45.tinypic.com/qqy5ut.jpg)

I'll be using the right-angle pots from Futurlec, so mounting them on the side of the enclosure seems logical. The drawing isn't to scale, but I'm pretty sure everything will fit just fine. I'm hoping to put together a cool graphics layout together for this one--probably using Rick's overlay technique. I'm also considering using the extra pole of my rotary switch for LED indicators for each waveform. We'll see though.

Hopefully tonight I can solder all the board components/pots After that, I'll lay out and drill the enclosure. This one will probably get a white undercoat, then a parts retrofit, then graphics, then assembly! I'm pretty excited to get this one up and running  :icon_biggrin:

After this, I'm looking at making one with some LFO mods--preferably a slow LFO to modulate the speed of the main LFO--similar to what some of the 4ms LFO add-ons do.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: thedefog on March 09, 2010, 10:32:46 PM
I'm posting on this thread since the other one I was posting to is a little dated (dec 27th).

I built my Gristileizer using the board that jacobyjd used in his initial post. At first I was having issues with the lfo speed. It was not getting slow enough (averaged a sweep around 1/2 a second at lowest settings). I remedied this by placing a 680k resistor at the input. Now I get a very slow sweep, which sounds like the other demos I've heard.

Currently, I'm trying to remedy the excess distortion in the circuit created. I'm assuming that it is the nature of the effect, but I'm not entirely certain. I've tried different resistor values on the initial input opamp, as well as the output opamp, but due to the other values in the circuit it doesn't function properly when I change the gain factor. I don't really know enough to figure out what is necessary to lower the overall output without adversely changing the way the circuit functions. Does anyone have any thought on this one?

Changed R22 to 100k and that seemed to tame the input volume enough without adverse affects on the effect.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on March 10, 2010, 01:39:37 PM
I'm posting on this thread since the other one I was posting to is a little dated (dec 27th).

I built my Gristileizer using the board that jacobyjd used in his initial post. At first I was having issues with the lfo speed. It was not getting slow enough (averaged a sweep around 1/2 a second at lowest settings). I remedied this by placing a 680k resistor at the input. Now I get a very slow sweep, which sounds like the other demos I've heard.

Currently, I'm trying to remedy the excess distortion in the circuit created. I'm assuming that it is the nature of the effect, but I'm not entirely certain. I've tried different resistor values on the initial input opamp, as well as the output opamp, but due to the other values in the circuit it doesn't function properly when I change the gain factor. I don't really know enough to figure out what is necessary to lower the overall output without adversely changing the way the circuit functions. Does anyone have any thought on this one?
Changed R22 to 100k and that seemed to tame the input volume enough without adverse affects on the effect.

I'll give that swap a try on my current build--I was down w/ the flu for 2 days, but I should be able to finish it by the end of the week. If that fixes the distortion, then awesome :)  I've been thinking about putting in some sort of pre-gain control, whether it be a switch or a pot to allow me to overdrive the effect or not. I kind of like it in some situations, but not in most--it kind of takes away from anything using just a clean sound.

Anyway, here are a couple pics of my build so far--most of the drilling is done. I had to alter my original layout idea, since the input jack would've been a little too snug w/ the pots--this would work with a straight cable, but with a 90deg head, it would be a pain. The jacks are going to go side by side on the audience side of the enclosure, with the DC jack snugged directly beneath the pcb. Still a bit cumbersome, but it all fits :)

(http://i48.tinypic.com/207kz0p.jpg)

(http://i46.tinypic.com/2s0bgh4.jpg)

Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: 1878 on March 25, 2010, 04:14:21 PM
I've finally got the time and parts to put this thing together next week. The Endangered Audio model has a footswitch for the VCA/VCF control. Have any of you succesful builders out there done the same ?? Is there any point ??
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on March 25, 2010, 04:16:55 PM
I've finally got the time and parts to put this thing together next week. The Endangered Audio model has a footswitch for the VCA/VCF control. Have any of you succesful builders out there done the same ?? Is there any point ??

Based on my results with this (still am debugging the one pictured above), I don't think it'd be terribly useful to footswitch that function. Mainly because of the amount of tweaking needed to get good settings between the two.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: skweeegor on April 04, 2010, 10:40:19 AM
Finally finished mine. Was going to put it in a hammond enclosure but I goofed on the layout and there was no way to fit it without resoldering so I stuck it in an old hdd caddy - looks kinda neat actually in a ghetto way. Might paint it eventually.

(http://i251.photobucket.com/albums/gg303/t0rmentlsd/gristleizer.gif)

Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on April 04, 2010, 01:11:36 PM
Nice. I think that look is very much in-keeping with the history and flavor of the Gristleizer.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: skweeegor on April 05, 2010, 12:27:44 PM
ok, I'm having some doubts as to whether my bias knob is working properly. Going by the endangered audio clip, it seems like in the VCA mode w/ a square wave it can act somewhat like a gate, but on mine it seems to just lower volume, and eventually the modulation. I dunno if that's a result of a difference in the way they wired theirs up or a mistake I made.

Here's an example of what I'm talking about:
http://www.mediafire.com/?a5t3ntmmdm2

Depth and Bias are at 100%, and the LFO is set to a square wave. From 0-9 seconds I'm adjusting the LFO frequency. Then at 9 seconds I start to turn down the bias knob - you can hear how it starts lowering the volume, and eventually killing the modulation as well.

Can anyone confirm if theirs does this too?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Kev77 on April 15, 2010, 02:23:42 AM
Finally finished mine. Was going to put it in a hammond enclosure but I goofed on the layout and there was no way to fit it without resoldering so I stuck it in an old hdd caddy - looks kinda neat actually in a ghetto way. Might paint it eventually.

(http://i251.photobucket.com/albums/gg303/t0rmentlsd/gristleizer.gif)



got a gut shot?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Plan B on April 15, 2010, 10:13:53 PM
posting this from my phone, so if it doesn't work, I'll give it another go in the coming days.  It was acid etched, the and I really should have planned the topography of it out a bit better.  Wanted everything on the front, but it got too crowded, so I run the risk of stepping on the vca/vcf switch and waveform selector.  Oh well.  Live and learn I guess.  Still gotta wire it up and see how it sounds, but I was rather pleased with the etch.  Now I'm debating whether to take the mask off or just leave it and let it chip away naturally.

(http://IMG_0303.JPG)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: skweeegor on April 30, 2010, 11:02:33 AM
got a gut shot?

No but I can take one in a bit. It's pretty terrible though - wires too long, all wound up in each other. Taught me a lesson in planning enclosures and wire lengths.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: 1878 on May 04, 2010, 02:08:53 PM
Just finished building my Gristleizer and it fired up first time !! I haven't tweaked it yet though, I'll do that when it's in the box to save knocking things out of kilter in between times.

As an aside, I'd like to thank Taylor for going to all the time and effort involved in getting these things sorted for us all. I'm not normally a 'gusher' but credit where credit's due... Thankyou.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on May 04, 2010, 02:58:16 PM
I'm always glad to contribute something to the forum.  :)

Now let's see some pics!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: 1878 on May 05, 2010, 09:59:33 AM
Just waiting on the ink for my printer. It's a good thing in a way, 'cos I'm still unsure about the design for the box.

Incidentally, what's the best way of posting video on this forum ?? Yes... I am that impressed with the Gristleizer !!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: hoso on May 07, 2010, 01:33:15 PM
I'm kinda n00b on all this stuff. This is my first build actually! I'm done soldering all of the parts except switches, pots, jacks, power AND the 470 nf cap (C1).

I only have an electrolytic in that value and now I'm wondering if I can put it on the board instead of bipolar? How do I do with polarity if I would do it?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: hoso on May 07, 2010, 03:15:52 PM
Sorry. I missed that question earlier in the thread. I feel like crying right now! No chance of getting that cap until next week :(

Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on May 07, 2010, 04:38:09 PM
Don't cry buddy, it'll work out!  :)

You can use a different cap value there, and it will have a slight effect on the max/min speeds of the LFO. So if you have something close in value, try that instead. It'll get you up and running at least until you can get the new cap, but you probably won't notice much difference anyway as long as you use something close.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: hoso on May 08, 2010, 11:50:08 AM
Thanks for those comforting words! I'm kind of short on caps and all I have are just really tiny values on bipolars. And I'm not in the financial position to buy an entire set right now. I'll just hang in there. I'm really psyched about trying it though. Fingers are crossed :)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on May 08, 2010, 12:49:22 PM
I seriously need to get back to debugging my first one using this board :(

I'm building one bone stock--that's the one on the bend at the moment.

For the second one, I'd like to fiddle with some fixed resistors on the pots to make them a bit more usable (Mainly the bias pot). This one will also be a non-stompbox version--I just bought a nice instrument enclosure from Jaycar that should do the trick. 

The last will have some multiple LFO madness going on--hopefully LFO controls for depth, volume, and speed
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: hoso on May 08, 2010, 01:28:06 PM
I love the fact that you'll have all the mods worked out for when I get number 2 in the making.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on May 08, 2010, 03:01:21 PM
I love the fact that you'll have all the mods worked out for when I get number 2 in the making.

Haha--I hope it works out that way. So far, I've got tons of projects and not a lot of time :)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: hoso on May 09, 2010, 09:24:47 AM
I accidentally dropped a solder blob in one of the small (unused?) holes on the board. Problem or not?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: hoso on May 09, 2010, 12:06:46 PM
When wiring a 3P4T rotary. Do I use pole A & B & lug 1-8 and wire the thing like in the diagram?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: 1878 on May 09, 2010, 12:51:31 PM
I used A & B, 1-8 & it all works for me. I wired it up exactly like the diagram too.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on May 09, 2010, 01:00:16 PM
I accidentally dropped a solder blob in one of the small (unused?) holes on the board. Problem or not?

Not a problem, doesn't matter.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: hoso on May 13, 2010, 06:51:35 PM
Ok, so I finished the thing. And for some reason I got + and - wrong so I probably destroyed the whole thing! I'm the worst Gristleizer builder ever.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: 1878 on May 22, 2010, 04:39:09 AM
I built this a week or two ago and it fired up first time. I fitted it into the enclosure last night and now it doesn't work :( This is what I've found so far...

The LED flashes as it should. Speeds up/slows down etc.
The background noise gets louder as the volume is turned up.
Clean signal in bypass.

Anyone know of any points where I may have blown something etc ?? Also, does anyone have any voltages before I get my meter fired up ??

Thanks.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on May 22, 2010, 05:03:40 AM
It's unlikely you blew anything just from putting it in the box. More likely something is shorting out to the enclosure. Check to see if any part of the circuit is contacting the enclosure.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: 1878 on May 22, 2010, 02:43:35 PM
I took it out of the box, still nothing. I've replaced all the transistors and IC's (I love sockets) and still nothing. I checked them all over with my meter and everything seems fine, including some variable readings on the TL074. I've replaced the 3PDT with a DPDT I had lying around but all to no avail.

The LED flashes as it should. Speeds up/slows down etc.
The background noise gets louder as the volume is turned up.
Clean signal in bypass.


The above still stands, but I'd wired the pots 321 instead of 123 which has now been remedied.

I am seriously confused, and it's made worse by the fact that it was working perfectly yesterday  :icon_cry:
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on May 22, 2010, 03:10:27 PM
Ok, if you're getting +9v and -9v where you should, and the LFO is working, that means that all is well with the MAX1044 and the TL074. So it's just the audio path you need to check, including the FET. Go through with an audio probe and find the spot where the audio dies.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on May 22, 2010, 03:24:28 PM
It's not unusual after some serious fiddling with an effect that after all that turning back and forth, for example checking positions in an enclosure, that one of your wire's out from the board has broken or lost contact. It can still be attached, but a cold solder joint has been exacerbated to the point where the bit of solder that was carrying signal is broken. Check for continuity.
This is a classic problem "it worked before I boxed it up", so you will find the answer. What did you do to it when you put it in the box? Did you remove anything to fix it in the enclosure and then reconnect, did that go back together right? Trace your steps back.
Good luck
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: 1878 on May 22, 2010, 03:44:57 PM
You could be on to something there. I want the controls in a slightly different order than what the board would give, so I've attached wires. Some of the wires were too short so I removed them and added new ones. I was a bit edgy and tired after a weeks work and I rushed it all. I'll set an hour or two aside one night and do a proper job.

I'll get the audio probe onto it tomorrow. It's probably something really simple... Hopefully.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: shaolin_skate on June 21, 2010, 10:10:50 PM
Hi, first post on this board. Been looking for info on the Gristleizer. I am using a protoboard layout and had just started soldering the IC sockets when I came across some questionable information. I am reading the TG biography "20 jazz funk greats" by Drew Daniel, and in the forward he mentions the Gristelizer. This quote is from the last paragraph of the preface: "...members of TG have copped to deliberately misleading the public with partial self-revelations in the past (such as Chris Carter's admission that the published schematics for his custom-built "Gristle-izer" contained inaccurate voltages inserted into the plans with the express purpose of throwing people off the scent and sabotaging any attempts to copy his design)."
Anybody know about this? I am using the Gauss-Markov schematics by the way. Has anyone actually got this thing working and confirmed it's proper operation? Thanks.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on June 21, 2010, 10:24:17 PM
I have gotten the gaussmarkov project up and working. Check out my build report by searching this forum. It's a fun circuit.

Taylor's PCB is essentially the same thing, just a little more modernized and mod-friendly.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on June 21, 2010, 10:39:31 PM
Lots of people from various forums have built this with my PCB and found it to work (I of course have too). I believe most people who build this bypass any info from TG completely and go straight to the GEP article that Chris Carter built his from. Roy Gwinn, who is a member here, is the designer, not Chris Carter, and though I'm no TG fan and don't know much of their history, I would assume he built it straight from the article.

I mean no offense to those guys, but I don't imagine they knew or cared much about electrical engineering, just like most musicians, so I wouldn't put too much stock in any grandiose claims of their "inventions". I don't think they did anything to this circuit but name it and make it popular (by the standards of industrial noise effects, anyway).
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: mrfang on July 24, 2010, 01:54:00 AM
Thanks Taylor for a great PCB design!

I built my Gristleizer with minimal stress this evening, and it works, but I'm having that ticking problem that other people have mentioned.  It doesn't seem to be lessened by adding the optional 10uF cap, or other values of caps in that same spot.

Does anyone have a confirmed solution to the ticking problem?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on July 24, 2010, 05:05:27 PM
If you read through the thread there have been a number of suggestions like putting a cap across the IC power pins, etc.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: 1878 on August 31, 2010, 02:35:48 PM
I finally got this boxed up !! No gut shots as yet 'cos it's a shit tip, and I wont have time to fix it before I move house.

(http://a.imageshack.us/img291/7849/gristleizer.jpg)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on August 31, 2010, 02:40:27 PM
Cool! What's the c/p switch?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: 1878 on August 31, 2010, 02:48:58 PM
Nothing too interesting unfortunately. It's the 'Cap or Pads' switch for the optional 10uf cap. I've tried a few different values in there with differing results. I think it's a 100uf at the moment.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on August 31, 2010, 05:18:50 PM
Really like your graphic/colours, simple eye-catching and colour coordinated, top marks  :icon_mrgreen:
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: 1878 on September 01, 2010, 04:40:04 PM
Really like your graphic/colours, simple eye-catching and colour coordinated, top marks  :icon_mrgreen:

Cheers  :icon_biggrin:
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: ren on September 04, 2010, 06:31:49 PM
Hi.
I've got the diy kit from endangered audio and I have the same ticking problem (even in Bypass).
In my stompbox the ticking depends on the position of the bypass switch and the output jack relative to a spot of the PCB.
Probably some kind of cross talking. But I don't know, if shielding the wires solves the problem completely. Just an idea.
Removing the LED had no effect on the sound.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on September 04, 2010, 06:54:59 PM
Hi there, I can't tell whether you're offering help or asking for help. If it's the former, thanks for contributing! If the latter, I'd suggest talking to the Endangered Audio guys. They had some unkind words for me at one point, because I created this PCB - so I'll abstain from discussing how to work with their board as this seems to offend them.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: ren on September 23, 2010, 06:08:08 PM
Hi Taylor & the ticking pals,
unfortunately the guys from endangered audio didn't reply to my mails. Probably they get pretty much questions like these.
Of course I will be glad, if you have an idea how to help me.  :icon_biggrin:
I've read the whole thread. Removing the LED had no effect. Solder a cap to pin 4 and 11 of TL074 isn't possible, because the EA-schematic uses completely other ICs, as yours does.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on September 23, 2010, 06:12:57 PM
On the TL074, pin 4 is power and 11 is ground, so just look up the datasheet of the ICs they use and if you want to try the cap, put it across the power and ground pins of the chip, minding the proper polarity if using a polarized cap.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on September 24, 2010, 04:56:40 AM
If it's ticking in bypass haven't you got a solder bridge somewhere? sounds like the tick must be getting into your ground for it to do that, just speculating (I'm not an EE)
Check out Oldschoolanalog's comments on changing the IC above, I have no ticking on mine, but of course it's not the same board.
Good Luck
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: ren on September 24, 2010, 09:47:39 AM
Putting a large value cap at the V+ and V- pins of the single op amps had not any influence on sound.

Endangered Audio sent me 6 (no double or quarter ICs) parts of UA741 instead of the LM741, which you can find in their assembly guide.
Maybe these op amps cause the ticking? I've read the data sheet (http://www.datasheetcatalog.org/datasheet/stmicroelectronics/5304.pdf), but I don't know, which is the significant value (consumption).

To bridge the bypass switch is some kind of difficult, because the two eyelets on the PCB are a few centimeters away from each other. Soldering a cable between them, there is the same "antenna effect" that the bypass switch caused.

Thanks a lot for helping me so quickly!  :)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: ren on September 29, 2010, 09:13:05 AM
I will replace the UA741/LM741 (supposedly the same) with TL061 single op amps.
The bypass wires will be replaced with coaxcables (shielded).
I'll keep you posted.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: ren on October 06, 2010, 01:43:36 PM
I replaced all UA741 with TL061. Ticking is a little bit more quiet, but still unacceptable.
Shielding the bypass-switch wires didn't help very much too.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on October 06, 2010, 03:15:12 PM
    I'm sorry, I don't really have any good advice for you, it would seem there is a chance that some of the problem lies in the layout or your wire routing. I don't think it's really the biggest issue here, but when you used shielded wiring, did you remember to ground the shield at one end.
    Presumably the EA guys built a prototype that didn't tick, check their build info again.
    I assume you have tried all the above "fixes" simultaneously.
    Good luck
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: ren on October 07, 2010, 03:04:24 PM
Your advice wasn't that bad. I actually forgot grounding the shield.
Now my Bypass is absolutely clean, without any ticking or other noises.
Engaged, the LFO is still draining, but that's no problem.
I also tried the grounded circuit input true bypass schematic, but this was noisy too.

Thank you for your help!  :)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on October 07, 2010, 05:13:29 PM
Great, glad I could help with something :D
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Derringer on October 15, 2010, 08:01:38 PM
here's a little improv gristleizer based jam my drummer and I got into a little while back


100924 gristelizer.mp3 - 1.85MB (http://www.zshare.net/audio/81592668ff652257/)

and if zshare is being lame for you the way it is for me atm

http://www.megaupload.com/?d=5BMVDSG0 (http://www.megaupload.com/?d=5BMVDSG0)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: digi2t on November 03, 2010, 01:31:50 PM
My Gristleizer is finally done. Took me a while to troubleshoot because of a bad trace on the board. Don't worry Taylor, my bad. I'm a noob at this, but it sure gets your brain box working. Wacky effect, but deadly when combined with a fuzz pedal (Tycobrahe Octavia in this case). VCF mode, along wth the Octave on, can get crazy.

(http://i214.photobucket.com/albums/cc196/digi2t/Pedals/Pedals004.jpg)

Here's a look at the guts...

(http://i214.photobucket.com/albums/cc196/digi2t/Pedals/Pedals003.jpg)

Don't think I'm going to paint it. Just leave it dull, and grey, and keep everyone guessing. Same for the Tyco. They'll be my twins on the board.

I also included two expession pedal jacks for depth and speed. I'm thinking about maybe MIDI'fying this sucker, but I might make another one on veroboard and experiment on that one. We'll see....

I'll post sound clips when I have some time.

Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on November 04, 2010, 02:57:01 AM
Looks great!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: digi2t on November 05, 2010, 11:35:27 AM
Thanks Taylor. Your PCB really is the cats ass, just that I ruined one of the traces between a diode and a resistor when I was debating which diodes I would use. Luckily they were right next to each other, so a small jumper (after hours of head-thumping troubleshooting) was called for.

To tame it down for guitar use (especially when I run fuzz pedals along with it) I found that adding the "4" to the 1 & 2 equation for VCA adds a bit of high end filtering. Especially if you go to exteme bias setting, the ticking is less noticable. I added a small toggle switch for this, it switches between the stock 1,3, or the tamer 1,3,4 in VCA mode.

I also added a 22k (I think... if I remember correctly, adjust to taste!!) resistor between the wiper of the bias pot and ground. Aurally, it seems to tame down a bit more of the hiss, and shifts the region of the bias somewhat.

I found that tuning this baby on a scope is the best way to go. Hands down, bar none. This tends to align the shape / offset / bias relationship best. With the bias knob set just in the right zone in VCA mode, I can shift between any waveform now and get that wave, without having to readjust each time. When I tuned it by ear, I had to constantly tweak the bias knob every time I changed waveform. Luckily, our electrical department had a PC based scope on hand (Hantek DSO-2090), which they were nice enough to lend me. Think I'll buy one though, for around 150$ it's a great tool. I used multi-turn trimmers for the shape and offset, this allows you to really hone in on the adjustment. Surpisingly, I found the bias knob much more of a trimmer in VCA mode than anything else. It has a much wider use in VCF mode, especially when the depth is set down low. I did use the reverse log 1M pot, as you suggested in your build notes.

To isolate the jacks from ground for the expression pedals, I used special swaged fiber washers, made by Switchcraft. They have a little shoulder machined into them, thus by drilling the hole a bit larger (7/16"), the shoulder sits snug into the hole and insulates the jack from ground. You use 2, one inside, one outside. They're only 1/32" thick, so most jacks will be long enough to get the nut on. In this case, I even got the metal washer on. Digikey part number is SC1147-ND, at 0.45$ each. I used 9-pin w/DPDT stereo switching jacks, from guitarelectronics.com. 6.95$ each.

As for the IC's, I ended going with ONSemi's MC33078PGOS, and MC33079PGOS. I tried 4 different sets (TL, TLE, MC3307, and LM613 series), as an experiment, and found this set to works best sound wise. They were the second cheapest as well, just above the TL series, and about 3 to 5 times cheaper than the TLE's and LM613's. Go figure. Take it with a grain of salt, that's just my ears.

As a precaution against cross-talk I also shielded some of the input and output wires. Nothing fancy, just gutted some 4 conductor Belden cable, wraped the wires in the foil, and slipped the outer casing over the works. Didn't notice any difference to tell the truth, but since the meter was running (my boss hates it when I say that LOL)...

There you go. For someone as technically challanged as I am, I'm quite pleased with the result. I even got to fiddle with an ocilloscope for the first time ever. Even moreso with the fact that I discovered this great forum. Thanks to one and all for any info I had to dig up. In a way, you all had a hand in this build. Thanks again.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: aleister on November 06, 2010, 06:26:58 PM
  I just finished a gristleizer build and after a couple problems it seems to be quite a cool pedal. This thing can go from subtle to over the top real quick.  Mine seems to have a whole lot of gain also, I really have not gone past 1 o'clock on the level pot.      Now I have a couple questions.  I assume the led is mandatory in this circuit?  I am not an led guy so I left it out and after about 3 minutes of messin with knobs I blew up the 2n3904, yup smoke, cracked case and all. So as precaution I also replaced the 2n3819, which was my last one ,with a 2n5457 and after a bit of knob messin I could see an orange glow from the bias pot when I turned it all the way down, then the smelly smoke came. So I then checked the pinout for the 5457 and saw that the gate and source were reversed. So after I replace that correctly and changed the pot it seems to be working as it should except for one thing, the led stays on even when i have the effect in true bypass. I will give it a critical eye a bit later cause I really just want to make some noise right now. I was just wondering if anyone may have experienced anything similar with their gristleizer builds?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on November 06, 2010, 08:34:32 PM
Unless you wired the LED on the board through your bypass switch, it does not turn off when the effect is bypassed - you need a second LED for bypass or you need to switch the emitter of the transistor with your switch.

It seems weird, but at the time I did this PCB design (about a year ago) I was under the impression that switching the flashing LED with the bypass switch would lead to bad ticking. So the idea at that time was that you'd use a second LED for bypass indication.

The other thing is that many people who build the Gristleizer (probably most people actually) don't build it as a pedal, and often there's no bypass at all for tabletop boxes and modular synth gear, so having an LED bypass switch would be confusing.

In hindsight I might do it differently, but it's always a compromise when designing a PCB that will be used in many different contexts/formats.

Quote
I assume the led is mandatory in this circuit?  I am not an led guy so I left it out and after about 3 minutes of messin with knobs I blew up the 2n3904, yup smoke, cracked case and all.

Hmm, no, there shouldn't be any need to put the LED in. I ran mine without the LED for some time. I'm guessing there was something else going on, but diagnosing it would take longer than loading in the LED.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: aleister on November 06, 2010, 08:56:00 PM
OK, I understand now. This probably would have been crystal clear to me had I not had a torched transistor. I was under the assumption that something else had gone wrong.  When morning comes I do want to trace through the circuit in some good light and see if anything is really amiss. I am hoping that I just had a dodgy transistor and i am sure this happens from time to time, although this is a first for me. Otherwise the circuit is giving me some great sounds and I don't think I have scratched the surface yet. Thanks for the help Taylor.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: digi2t on November 08, 2010, 08:42:48 AM
I personally did not mess with the board (flashing) LED myself. I did add LED's for bypass and VCF mode, but I took my power directly from the adapter, and wired these through 3PDT footswitches. I need the LED's because I've got so much shit at my feet, I need to see at a glance what's on, or not. Besides, I do a lot of rythym based stuff, and I run through an Adrenalinn 2, and a Boss Slicer, so the little flashing LED is a bit of a God send. Especially that fact that it's always flashing even when the effect is bypassed, this allows me to somewhat syncronize myself with whatever beat I've got going before I kick it in.

aleister, your units gain is about on par with mine. I put numbered knobs on mine (easier to record and recreate settings), and I don't go much past 1.5 or 2. I get the feeling that if I crank this sucka, I could play it with a 2X12 cab... direct.

Now.... can we make a tap tempo version of the Gristleizer. With MIDI. That can accept MIDI clock signals. If it's not too much to ask...
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: boblob on February 21, 2011, 10:36:47 AM
Just did one of these on good old vero/stripboard using a layout based on the one over at gaussmarkov, but taking the bias pot offboard. This is the one using the 5 discreet LM741s. I built this for table top use, with toggle switches for bypass and VCA/VCF modes and added a bypass indicator LED. I also took the input impedance up a fair bit using the resistor values suggested by gaussmarkov.

Works well, and is sounding like it ought to, but oscillator ticking is a problem (it bleeds through in bypass a little too on the ramp up/down settings, with the bias and levels cranked). Not sure is anyone has answered this (just read through this thread and didn't see it - appologies if it's bindun) elsewhere, but where on the schematic does the optional de-tick 10uf cap go on Taylor's schematic?

I have tidied up the wiring, which hasn't really helped and have adjusted the shape and offset trimmers as best I can (by ear and DMM - I don't have a 'scope). I've also tried placing a big electrolytic around the supply pins of IC1 and IC3, which doesnt help either. Would like to try  the de-tick cap next (if someone will kindly tell me where it goes), then sheilded wires for the in and out.

Over at gaussmarkov, Roy Gwinn (the man himself), reckons that ticking will most likely be a layout problem - specifically the location of the "integrator cap" (I think he means either the 470nF in the feedback of IC1 or the 2.2nF across IC3). Since ticking is a problem on vero, Taylor's and it seems Endangered Audio's layout I think there's other issues too.

Soundwise, the VCA is a really decent tremolo, the VCF sounds pleasantly burbly if a little harsh on the treble side. As others have mentioned - an external bias pot (rather than an onboard trimmer) is pretty much essential. There's an overall lo-fi sound that I guess is partly down to the LM741s, which I like. Not managed to get it to self oscillate (even with that big LFO tick). I'd have a lot of use for this if I can tame the pesky LFO ticking.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: boblob on February 21, 2011, 11:25:31 AM
Just to add - re-read the thread and see that according to Roy, Taylor's de-click cap is supposed to be between the depth wiper and ground, providing an extra bit of filtering before the stock low-pass filtering arrangement of R15, R16, C5 and C6. Just tried this, but hasn't helped with my ticking problem.

Looking at gutshots of Chris Carter's Gristleizer, it looks like he's used shielded cable for board out to level pot (http://www.flickr.com/photos/yurisuzuki/4140697611/in/set-72157622768379175/#/photos/yurisuzuki/4140697611/in/set-72157622768379175/lightbox/). Looks promising - according to EA (and I think CC has said similar), they managed to de-tick theirs without any additional filtering - maybe this is what they are obtusely referring to, simple shielding. Something else to try, at least. Shielded cable on the depth wiper - board might also be an idea...
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: boblob on February 21, 2011, 12:47:08 PM
Another quick update - sheilded cable on the output seems to have had minimal impact. However, I have managed to get it to self-oscillate (yay! a first for diystompboxes Gristleizer builds?) by tweaking the offset trimmer and bias.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: glops on March 22, 2011, 03:12:01 AM
I got a dumb question.  According to this picture on page 1, if you look at the bottom left of the board at the SPEED 10K A holes, from left to right, what would be the corresponding 3-2-1 for the pot connections?  Does that make sense? This is first time with a PCB, so don't know what the standard is. I've had this PCB for over 3 months now and it's almost completed.  I would like to not have to resolder the 3 and the 1, ya know.

Thanks,
Richard
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on March 22, 2011, 03:39:55 AM
Looking at the front of the board, with the component legend readable correctly, the counter clockwise lug of each pot is on the left. Not a dumb question at all, and in the future this info will be on the board.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: glops on March 22, 2011, 03:54:55 AM
Looking at the front of the board, with the component legend readable correctly, the counter clockwise lug of each pot is on the left. Not a dumb question at all, and in the future this info will be on the board.

That's what I thought, just wanted to make sure.  Can't wait to fire it up, have never used a rotary and that will cause some stress but hopefully tomorrow I'll test it out....
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: glops on April 22, 2011, 04:07:41 PM
Finally finished it up!  The reverse etching didn't come out as clean as I originally intended but I think it came out better this way.  No paint, just some scrubbing with a brush and a clear coat.  It sounds great Taylor!  Thanks so much for making this board. I posted more pics on the pics thread...
(http://s3.amazonaws.com/data.tumblr.com/tumblr_lk2kfk5IM31qiaokho1_1280.jpg?AWSAccessKeyId=AKIAJ6IHWSU3BX3X7X3Q&Expires=1303588865&Signature=Y15vC5xzBWNSicsyPqfWR3AAMAk%3D)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: jacobyjd on April 22, 2011, 04:13:32 PM
Yeah. That's awesome.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on April 22, 2011, 06:47:37 PM
 :icon_eek: Love it.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: 1878 on April 23, 2011, 06:27:23 AM
Ooh... I like that.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: glops on April 24, 2011, 03:28:48 AM
Pictures got lost in cyberspace.  Here again.  What a cool circuit!

Thanks Thanks Thanks!!!
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=45094&g2_serialNumber=2)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: digi2t on April 24, 2011, 08:29:21 PM
Wow, absolutely superb. Love the hash marks around the knobs as well. BRAVO!!

Cheers,
Dino
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on April 24, 2011, 11:21:59 PM
Did anyone implement the expression pedal input for LFO Rate/Speed knob?

A broken pot (long story) gave me opportunity to go under the hood and try this according to Taylor's switching-jack diagram as per page 6. I'm not getting any results though. I tried with the Moog expression pedal as specified, also with a Boss one, no dice with either.

Fortunately I still get normal rate knob behavior when the jack has nothing inserted in it. But I'm hoping to still implement this while I've got this "up on cinderblocks in the front yard" so to speak.

If anyone can help and/or verify that wiring diagram or alternate rate expression configurations that would be great!

thanks
STRATEGY
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on April 24, 2011, 11:37:20 PM
I can't think why my diagram wouldn't work - it's just subbing the pot in the expression pedal for the panel pot.

If you mixed up the sides - wired the PCB pads to the switched side - then it wouldn't work. I guess it could be ambiguous what "switches" meant here, so verify that the side connected to the pcb is connecting to the plug when inserted. In this jack:

Http://www.smallbearelec.com/Detail.bok?no=771

The "switches are on the left side in that picture. In this one it's the other way around:

Http://www.smallbearelec.com/catalog/Nmj6hcd2.jpg

Notice the way the pins on the non-switch side come up and bend over the top to contact the plug.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on April 25, 2011, 12:32:51 AM
Yep, the pot is attached to the switch side so that when you insert a cable into the jack, it disconnects the pot from the pcb and substitutes the pedal. Maybe I have the pcb-side wires going to the wrong pins of the jack. I'll check again

Strategy

I can't think why my diagram wouldn't work - it's just subbing the pot in the expression pedal for the panel pot.

If you mixed up the sides - wired the PCB pads to the switched side - then it wouldn't work. I guess it could be ambiguous what "switches" meant here, so verify that the side connected to the pcb is connecting to the plug when inserted. In this jack:

Http://www.smallbearelec.com/Detail.bok?no=771

The "switches are on the left side in that picture. In this one it's the other way around:

Http://www.smallbearelec.com/catalog/Nmj6hcd2.jpg

Notice the way the pins on the non-switch side come up and bend over the top to contact the plug.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: digi2t on April 25, 2011, 03:05:20 PM
I used this diagram, http://picasaweb.google.com/lh/photo/agO0OKTabUMuBF9PjMwzfg?feat=directlink (http://picasaweb.google.com/lh/photo/agO0OKTabUMuBF9PjMwzfg?feat=directlink), and have 2 expression pedal jacks. One for depth, and one for speed. Just make sure you insulate the jacks from the casing though. I used the shoulder washers from Switchcraft. The jacks are stereo switching jacks, with a N.O./N.C. contact on the tip and ring. Got them from here; http://www.guitarelectronics.com/product/JK31/9-Pin-14-Stereo-Jack-w-DPDT-Switch.html (http://www.guitarelectronics.com/product/JK31/9-Pin-14-Stereo-Jack-w-DPDT-Switch.html) .You can see them, upper left of the enclosure (next to the stomp switch). I use a 100K volume pedal as the expression pedal.

(http://i214.photobucket.com/albums/cc196/digi2t/Pedals/Pedals003.jpg)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on April 25, 2011, 06:14:21 PM
Thanks for posting that.

So, I think that one issue for me is this: I used a 100K moogerfooger expression pedal and it would appear to not work for LFO speed because that is a 10K Audio taper pot. By that, the 100K should reach maximum resistance very quickly.

I tried my 10K boss expression pedal and that did not work either, though, so mystery still unsolved.

I'll try the expression connections in your diagram you posted in the link

thanks
STRATEGY
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: thedrivel on April 26, 2011, 10:49:24 PM
The only JFET Small Bear has is the 2N5461. Will that be ok in place of the 2n3819?

http://www.smallbearelec.com/Detail.bok?no=1071

Also, how to I determine the correct resistor for the flashing LED? I was planning on getting this one in green:

http://www.smallbearelec.com/Detail.bok?no=333
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on April 26, 2011, 11:06:06 PM
According to the original designer of the circuit, Roy Gwinn, any JFET should work. Since the bias can be trimmed, differences in individual JFETs can be accounted for. Note that they may not have the same pinout, and make sure you've got the pins going to the right points - the gate, drain, and source are marked by "G D S" respectively on the PCB.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: thedrivel on April 28, 2011, 11:13:49 AM
According to the original designer of the circuit, Roy Gwinn, any JFET should work. Since the bias can be trimmed, differences in individual JFETs can be accounted for. Note that they may not have the same pinout, and make sure you've got the pins going to the right points - the gate, drain, and source are marked by "G D S" respectively on the PCB.

Thanks Taylor. I see that Mouser has a few 2n3819s. I'll just buy what the BOM calls for. I don't know enough to improvise, but I can follow directions okay. Earlier in the thread you mentioned you were creating a mouser part# list I think. Did you finish it? Excited to get cracking on this after building your Tap Tempo Tremolo.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on April 28, 2011, 03:41:12 PM
Generally for all the projects, for parts that need to be one specific part, I include a part number. For most things, people use all different kinds of caps and resistors, etc. so it wouldn't make too much sense to include part numbers for some arbitrary brand and tolerance value.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: boblob on May 14, 2011, 07:19:58 PM
I've built a couple of these now on vero with a revised layout using two TL072s (one for the input and output buffers, one for the oscillator) and a single TL061 (for the waveform-shaping bit).  The 741s don't really bring anything special to the party - the lower current more modern ICs sound very much the same to my ears. I did have to sub a couple of resistor values in the oscillator to give it a good usable range and upped input impedance has also been upped to ~ 1M, otherwise it's the same as the 741 version.

Ticking problems are greatly mitigated by using good quality shielded cable for the input and outputs, and also, importantly, on the VCA/VCA switch. What helps most though is to increase the value of the 100uF decoupling caps - on the breadboard going up to 220uF greatly reduced ticking with 470uF completely eliminating it; I had to go up to 1000uF on the final vero and siting them as close as possible to the power pins of the oscillator IC also helps.

Taking down the corner frequencies on the pair of low-pass filters also got good results - I went with a 100k + 200nF and 150K + 100nF combination (Taylor's 10uF de-tick cap did nothing for my build). Limiting current to the oscillator IC didn't do much either except make the LFO pulse too weak to get distinctive waveforms. I also tried subbing the oscillator for the less brutally square one from the Stompbox Cookbook, but again it couldn't produce the nicely defined waveforms that you get with the stock LFO.

Phew. I have learned tons of useful stuff from this build - if you've already tackled a simple tremolo or the like, then this is a really good build to take you up to the next level.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: fleeps on May 22, 2011, 08:18:09 PM
Pictures got lost in cyberspace.  Here again.  What a cool circuit!

Thanks Thanks Thanks!!!
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=45094&g2_serialNumber=2)

Love it!
I guess you solder the pots directly onto the pcb? I'd imagine the knobs would be closer together....
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: glops on May 22, 2011, 08:45:17 PM
Pictures got lost in cyberspace.  Here again.  What a cool circuit!

Thanks Thanks Thanks!!!
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=45094&g2_serialNumber=2)

Love it!
I guess you solder the pots directly onto the pcb? I'd imagine the knobs would be closer together....

I didn't solder the pots to the PCB, just wires going from the pot pads to the pots.  Thanks, man!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: samE on July 27, 2011, 08:10:49 PM
hello hello, just wanted to say what a grate community you lot have her, my question is this:regarding the griserlizer project what are the best capacitors to use?. Currently i have ceramic caps in place, however my friend tells me, for audio circuits i should use polyester box caps. so will it sound better with the poly caps? or does it even matter?

 :D
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on July 27, 2011, 08:57:45 PM
My personal opinion is that it doesn't matter. Other people disagree. In my experience, the difference between 2 caps from the same batch but unmatched will be far larger than the difference between 2 caps of different dielectric material but with the same exact measured value.

Besides the question of whether there is any difference at all, the assumption is that film caps are cleaner or more hi-fi or something along those lines. The Gristleizer, however, is an experimental noise effect, so even if this line of reasoning were true it's debatable that film would actually be better.

Chris Carter (who popularized the effect and gave it its name, in his band Throbbing Gristle) actually bought some of these PCBs from me. I suppose I could ask him whether he thinks film caps matter.  ;D
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: glops on July 27, 2011, 11:22:15 PM
Chris Carter (who popularized the effect and gave it its name, in his band Throbbing Gristle) actually bought some of these PCBs from me. I suppose I could ask him whether he thinks film caps matter.  ;D

That's really cool!  They're really scary...  You have any new stuff in the works, Taylor?  I need to try the OC2.  Bought a couple of tiny giant kits from you but realized that I need "quiet" amps.  I was going to have two of these for testing sounds in parallel in my shop.  Have the speakers so I should probably just do it.  Hopefully, I can keep them at lower volumes since I got a massive complaint from a neighbor and have to keep it really quiet...  :icon_cry:
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on July 27, 2011, 11:32:56 PM
Yeah, I thought it was pretty neat. I have come into contact with some folks that are relatively well-known, but getting an order from the person who put the effect on the map is pretty cool - like if you sold a Whammy pedal to Tom Morello.  ;D He bought 4 of them - so in my nerdy dreams I imagine he's built one for each member of TG and they're all Gristle-izing away with the board I made.

Re: new stuff, just put the Meat Sphere up on the site. Have some other things but it's just been tricky to find time to build prototypes/tweak designs. I need to update the "coming soon page" or whatever I've called it...
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: glops on July 28, 2011, 12:25:08 AM
I saw the meat sphere thread right after I posted last.  I actually just fixed a mutron 2 yesterday.  I bought it for 80 bucks on ebay about 6 months ago and its just been sitting around.   One of the electros had snap and the pots needed some care.  works great now.  awesome, you have a new project.  I have been buying little doses of prefabbed boards lately.  I enjoy them a lot, but the GR and the Echobase are my keeper favorite non fuzzes.  Thanks for your service, look forward to the future!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: WWWizard on August 21, 2011, 08:09:40 PM
Hi gang,
I'm fairly new to working with electronics other than simple repairs / circuits etc.. This is my first real build. Exciting but has proved to be challenging.

As expected -- I'm having trouble getting the build to run. I just set it up for my first test and am only hearing my clean single.
No LED action / Volume pot adjustments either.

Wondering where to start troubleshooting? Is there someway via metering I can find out where the problem is?

I did a clean and thorough job soldering and feel like components are properly placed.  (perhaps the rotary is sketchy)

After hooking a 9V power up should the LED automatically light up without any audio signal?

Any help would be really great. My lack of experience might lead to this being a really simple mistake that I have ignorantly overlooked.

The (+) (-) direction only applies to those elements which are polarized and also labelled on the board, correct?

Just want to work through it and see if I can get it running.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on August 21, 2011, 09:21:34 PM
Yes, the LED should light up without regard to audio. Here is the best place to start with debugging pedals:

http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

Especially check the links towards the bottom.

Specifically in regards to the Gristleizer, some important starting places:

1. do you have -9v (note that negative 9 volts, not positive 9 volts) at pin 5 of the MAX1044?

2. Do you have any way to look at the waveform of the LFO (oscilloscope, scope program on your computer)?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: WWWizard on August 21, 2011, 10:27:20 PM
Thanks Taylor.
Good, helpful resources. I will look over them in more detail.

For now:

I am metering .89V on Pin 5 of the MAX1044.
(I see now on the schematic that it should be -9V)

Yes, I have scope software on my computer -- If I can manage to make it to that point.

Any other significant points to meter/values? Transistors?

Thanks for the prompt response. I've got some reading and reviewing todo.

Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on August 21, 2011, 10:36:11 PM
Ok, so your MAX1044 isn't doing its job. That's the first thing you should get going.

When I first started building, all of my problems were bad solder joints and wires that were poorly strip and were therefore intermittent. Reflowing all of my joints and getting a proper wire stripper really helped.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: WWWizard on August 23, 2011, 12:28:08 AM
Do I need to have any wires connected to the IN and OUT sockets to troubleshoot using the maxx1044?
Also would improper rotary wiring affect this reading?

Many thanks again.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on August 23, 2011, 01:49:02 AM
No, it's just making negative voltage out of the positive power so it doesn't do anything with the audio.

The switch is part of the audio section so won't affect the 1044 unless you had a wire or solder bridge from the switch grounding out some part of the 1044 or its surrounding caps.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: fegg on September 06, 2011, 05:42:18 AM
hi, I'm almost done populating one of taylors boards (nice board it is too) and just realised i dont have a 2n3906 what can i use instead. I have bc558b or will that introduce noise?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on September 06, 2011, 06:16:10 AM
I suspect any general purpose PNP will be fine there, just mind the pinout of course!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: fegg on September 06, 2011, 06:24:53 AM
ahh thanks Taylor, I was hoping that was the case, I'll socket it and try a few.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: samE on October 02, 2011, 12:06:47 PM
hi, i am having some trouble with the bypass switch, i am using a 3PDT Toggle switch, and rather then toggling up and down it toggles left and right.

so the toggle here is on at the top and bottom (standard)

example:1
    X
   III
   III
   III
    X

and the toggle here is left and right (the one i am using)
example:2

  III
XIIIX
  III


i have wired the switch using the link on the PDF : http://i38.photobucket.com/albums/e101/putzdaddy/offboardwiringfordiy.jpg.
and it does not seem to work.
is there a different method for the two switch's?

any help would be grate thanks.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on October 02, 2011, 04:53:15 PM
I'm a bit confused - what does it mean for a switch to toggle left/right rather than up/down? If you rotate it 90 degrees doesn't it become up/down?

Can you post a link to your switch, or a photo?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: samE on October 03, 2011, 07:06:26 AM
http://www.taydaelectronics.com/catalog/A-1955.jpg

i will wire it today on its side, maybe that will work.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on October 03, 2011, 08:28:00 AM
Take your DMM, or a bulb and a battery for that matter, and test continuity between the outside poles and the common middle poles as you flip the toggle.
When the toggle is in an up/down position ( moving in the vertical axis) and the toggle is down the middle row and top should have a connection, when the toggle is up the middle and bottom row should have a connection. Test with DMM to check you don't have a faulty switch.
(http://www.stewmac.com/freeinfo/i-1561/1561_dia5.gif)

So when the toggle is down poles 1 and 2 are connected, poles 4 and 5 are connected and poles 7 and 8 are connected.
Generally speaking though, the fastest way to understand this is to use a DMM and sit and test it, you'll understand it in five minutes.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: samE on October 03, 2011, 10:59:35 AM
thank you for your help, i just flipped it on its side and applied the same wiring scheme, works fine now.... :icon_redface:

so its finally finished my stompbox version, minus the art work.....  ;D

http://www.flickr.com/photos/67563147@N03/6207906874/in/photostream


I will finnish the artwork then ill move on to a table top version

and again thanks for all the help.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: fegg on October 06, 2011, 09:17:02 AM
hi these are the outputs from a pc scope of my gristleizer can't seem to get the triangle any better adjusting the shape trimmer ???
also I have no idea about the offset adjustment.
  I'm using a mono guitar lead into the pc sound card the end I'm probing the circuit with is unshielded wire to ground
and shielded to the + pad on the optional 10uf cap or centre lug of depth pot, both produce the same output,
 anyone have any comments?
(http://img849.imageshack.us/img849/1435/scope.th.jpg) (http://imageshack.us/photo/my-images/849/scope.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: fede409 on November 14, 2011, 02:50:47 AM
Hello, I present my version of gristleizer, I just need to remove some tick tick, I hope it increases the value of decoupling caps. I used the PCB gaussmarkov. I thought about changing the value of BIAS pot to 500k for better control. Am I right?

I want to thank Roy Gwin for making public this great circuit and everyone on the forum.

Cheers! :icon_biggrin:

Sorry for my bad English.
From South America (Argentina) Federico.

(http://img703.imageshack.us/img703/4370/dsc09021r.jpg)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Skruffyhound on November 14, 2011, 07:52:58 AM
Nice work Federico. Control knobs are interesting.
Quote
BIAS pot to 500k
I'm too lazy to check the schem, but if the original pot was smaller than 500k then you might get the opposite effect. In some situations you can change to a smaller pot to get a longer control sweep. Try it. The other possibility is to change the taper you are using. If you check in the start of this thread I think I ended up using a rev log for bias after Dave (oldschoolanalog) suggested it.
Good Luck
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: bassesofdeath on November 14, 2011, 09:01:59 AM
A question regarding the use of 4 position rotary switches. Has anyone use the Mode Switch For The Q-Tron OR Stereo Polychorus from Small Bear, for a wave form selector?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: glops on November 14, 2011, 11:40:26 PM
(http://img703.imageshack.us/img703/4370/dsc09021r.jpg)

Great lookin' box for a great circuit.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: fede409 on November 17, 2011, 04:02:56 PM
Hello, I remove the tick placing the caps between v + and v- of the integrated circuit as discussed before, but I have to remove a whistle coming from the ICL7660, to place instead of max1040, I could not find it!!!
It happens that the 7660 is not exactly like the 1040. 7660 to create a negative voltage produces a frequency oscillations that can be heard, while the 1040 does not.
I hope my comment is useful for someone. :icon_biggrin:
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: gigimarga on November 17, 2011, 04:13:24 PM
Hello,

I've just finished a Gristleizer and I can't find any informations about how to set the BIAS trimpot...the LFO waveforms are OK all, but the effect it's too weak...when I modify the BIAS trimpot it becames harder, but distorted...I used a 2N3819 FET.

Thank you all!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: TheVoiceOfSaturng on December 23, 2011, 09:58:42 PM
(http://2.bp.blogspot.com/-dmyA9vTXjxY/TvUztlVM3II/AAAAAAAAAIw/71faOFmPJhA/s320/photo.JPG)

I just finished my Gristleizer this evening and even got to make some noise with <a href="http://soundcloud.com/recompas/gristly-noodle">here</a>.

I'll post the guts photo shortly.  I initially had the 10uF cap that was optional installed and found that it severely changed the shape of the waveforms.  Chopping it off get me some nice waves on the scope.

I also added a CV input to the circuit.  Instead of connecting the outer leg (not the one connected to ground) of the depth pot to the board, I put a switch in that connection that allows me to switch either the internal LFO signal or and external one into the depth control.  Easy mod and very handy for modular synth nerds!

-T
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Dumpster Diver on December 31, 2011, 02:57:18 PM
 HI, I'm new to this blog and also DIY circuit building. (thanks for having me on!) I'm a little stumped right now on my Gristleizer Kit I bought from Endangered Audio (Todd Kelley's design V.2)
First of all, What's up with the Smashing guitars webpage? No one is replying to my E-mail (so I can't exactly find any direct answers)  I have found the PDF diagram was a nightmare once I began to probe my board.
I can't get in contact with anyone From EA, to even ask for service (I'm a novice builder)...I think I could be pretty screwed. Right away There was an inconsistancy with C13 on the diagram, and the PCB (the polarity of the cap was one way on the board, and then the other way on the PCB)...once I began my troubleshooting, Switching it out had absolutely NO effect on the circuit...that means I'm not even accessing 75% of my PCB right?  so far I've made a few faults, The LED was backwards and also my mode switch got wired backwards in a hurry...there must be a few more things that I put in backwards in that case, but Again, the Diagram I got is next to impossible to read!!!
The point of panic for me was that I have accidentaly deleted my E-mail sent from Todd (yes, that was a full-retard move!!!) I could have SWORN there was a tiny tidbit of information from him personally that was not included in the PDF file....something perhaps like a jumper point near C12 and C11? I was left with a few extra resistors and about 2 inches of wire, maybe a few of my friends Resistors somehow got mixed into my assortment during the long-winded building session? either that OR Todd sent me a few extras by mistake? another thing worries me is that the IC's didn't come in a static bag, and some of them could be no good from the get-go.
(there are a few holes in the PCB where nothing is Labelled and it looks like I missed something totally obvious!) That being said, I will post what I can about the symptoms, and get some photos taken fo-shiz!


-J
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Dumpster Diver on December 31, 2011, 03:49:16 PM
Ok, This is the best I can do verbally to explain the problems with the Gristleizer.
So, the Square wave seems to be working better than anything else , The 'speed' pot has no effect on the other 3 waveforms in either VCA or VCF (the only waveform that "flashes" is the square in VCF, and the first ramp in VCA) what's interesting is that VCA mode doesn't produce any self-oscillation. I'm getting a bit of effect in VCA but nothing sounds like that Gritty texture I know I should be getting out of it. As I've mentioned before...my C13 has been soldered both ways and produced no change whatsoever.(meaning something isn't making connection, and I'm not accessing most of my board, or I've got a bad component)

There is also something WEIRD..sometimes when I am playing with the VCA/VCF mode switch and selecting waveforms with the rotary simultaneously, the Flashing waveform will sometimes Jump from the square wave position (hard right) back to the FIRST position (hard left) and vice-versa.
when I was calibrating the shape and offset, I first noticed that my Triangle wave was totally jagged and broken as with everything BUT the square wave.
Like I said, that's all I have to go on for now, I've tried both 18VAC and 9VDC with no change.
I'm looking to speak to someone who had similar problems or perhaps built this same kit with better luck than me.
I have no URL Address, so I will have to E-mail you PHOTOS if you think you can help?

also should add; I'm more than willing to pay good $ for professional service!

Things are starting to get a little restless.
For all it's worth, the truth is hard to swallow at this point, It would have been cheaper and quicker just buyng the pre-built $375 Gristleizer. I spent a month bussing around and living hard, spent well over $400 bucks on food and transportation...I'm not licked yet though...

if you can get me going I would be forever in your debt!

-Jules

Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on December 31, 2011, 04:27:23 PM
Hi Jules, this thread is mainly about building the Gristleizer board available at my site, musicpcb.com. I'm not really familiar with what the guys at EA have done with their version, and they have flamed me for talking about their board so I'm not too keen on dealing with that again. I can say that their version of the circuit is not the same as mine.

I'm not even sure if they make their schematic available to people who haven't bought their kit, so you'd probably need to find some people who have worked with their kit and circuit to really give you specific help.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Dumpster Diver on December 31, 2011, 06:43:20 PM
yeah, I was looking to find someone else out there who had built The EA Kit with more success than me.

thats too bad, I guess I'm not going to be making any progress at this point, total impasse.

I just sent an E-mail to Todd Kelley, If there's a bit of luck there, I will let you know.


your board looks awesome BTW!

Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: PerryLevy on January 24, 2012, 08:26:40 PM
Hello Taylor,

I need some help with setting the Trim pots on the SHape and Offset.  I have purchased an oscilloscope and measured using the LFO from the 10uF optional cap and I only can see the waveforms for Ramp Down and Squarewave (1st and 3rd position on my switch respectively).  The second position on my switch shows what looks like a Triangle wave but only when I turn my Depth knob all the way down.  The fourth position on my switch shows no waveform at all either with the Depth knob or Bias Knob in any position.  I have also used the scope attached to the center lug on the Depth pot and still there is no waveform.

Why can I not see the waveform on the fourth position on my switch?

I'm guessing that is suppose to be my Triangle waveform.

I have double checked all my wiring and the pedal sounds great except for the fourth position.

Thanks in advance for your help.


Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on January 24, 2012, 09:44:12 PM
Hi Perry, unfortunately it's been about 2 years since I built mine so I'm a little fuzzy on the details of how the scoping went. I would recommend reading the waveform from the depth pot wiper. Second, if you don't get any LFO signal in the fourth position, it's probably due to a bad solder joint around those parts or a faulty wire connecting the switch to the board. Try reflowing those joints.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: PerryLevy on January 24, 2012, 11:05:08 PM
Thanks for the input Taylor.

I have checked the switch connections are correct, the solder joints are good.

Does anyone else have any input on why I can't see a waveform when in the fourth position of the switch?

Thanks!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: samE on February 20, 2012, 05:50:27 PM
hello, I almost finished another gristleizer but i am having some problems. all of Wave shapes work except for the triangle, when set to triangle the sound has no shape to it with any setting, it simply sounds bypassed. I checked my wiring and it seems ok. would it be something specific that would course this fault?

any help would be amazing, as you can probably tell from my other questions, i am some what of a super noob :icon_redface:.

thank you in advance.
sammie
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 20, 2012, 06:18:35 PM
If everything works except one waveform, you likely have a bad solder joint somewhere in the waveshaping (lower left of the board) section, or perhaps a bad wire going to the rotary switch. Try reflowing those joints. You may also just need to adjust the trimpots a little more.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: samE on February 21, 2012, 06:49:52 PM
ok, thanks ill try that.....
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on February 22, 2012, 12:56:43 AM
I just modded my Gristleizer by adding vactrols to the filter depth/cutoff and lfo rate pots. Sounds awesome! A little funky, a real kludge way to implement control voltages, but very musical.

will post audio/pics maybe a diagram as soon as I get the thing all put together in the enclosure

Strategy
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on February 22, 2012, 01:28:10 AM
Apparently Buchla used optocouplers for a lot of their CV stuff, so... there's a good line to tell yourself and/or anybody who remarks at the slow/imprecise CV.  ;) You were going for that vintage Buchla organic feel.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Strategy on February 22, 2012, 01:25:53 PM
you do get the musical 'twang' on the VTL5C3 that is characteristic of the Buchla Lowpass Gate. A result of the natural slew of vactrols I guess. It sounds really good on the filter!

The VTL5C3 is not quite the right range for the LFO rate pot, but close.

Strategy

Apparently Buchla used optocouplers for a lot of their CV stuff, so... there's a good line to tell yourself and/or anybody who remarks at the slow/imprecise CV.  ;) You were going for that vintage Buchla organic feel.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: ottopit on February 24, 2012, 06:19:00 PM
Pictures got lost in cyberspace.  Here again.  What a cool circuit!

Thanks Thanks Thanks!!!
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=45094&g2_serialNumber=2)

Now that enclosure looks sweet!! How did you get the blotchy-texurized look on the enclosure? Is that from the etch?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: glops on February 25, 2012, 03:36:39 AM

Now that enclosure looks sweet!! How did you get the blotchy-texurized look on the enclosure? Is that from the etch?

It's a reverse etch with no paint and some clear coat.   Happy accident.  This is my favorite pedal but it's not working at the moment.

Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: candletears7 on March 28, 2012, 08:36:18 PM
Hi guys, I've built my Gristleiser, bypass is fine but nothing in effect mode.
I will check voltages on pin 5 of the MAX1044 to ensure I'm getting + and - 9v.
I also think I may have wired or set the rotary switch up incorrectly. It selects from 4 waveshapes, correct?

I have built too many pedals and the excellent Echobase, so I'm pretty confident it's a simple interpretation error on my behalf. I used ribbon wiring to keep it neat, I will post pics tonight after work. I'm tipping my questions will be about the rotary switch.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on March 28, 2012, 10:52:50 PM
When you say "nothing," do you mean that there's no sound throughput at all, or the signal passes through unaffected?

Yes, the switch selects four LFO waveshapes.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: candletears7 on March 29, 2012, 12:51:50 AM
No sound at all...Zilch. I wired it up exactly according to the wiring diagram. I'll start trouble shooting it when I get home, but I was kinda surprised at having no signal.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on March 29, 2012, 03:30:53 AM
I would recommend ignoring the rotary at first, and instead build an audio probe and use it to trace through the circuit from input to output. Finding out the point where the audio stops will go a long way to figuring out the problem.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: candletears7 on March 29, 2012, 07:20:01 PM
Yes, I have an audio probe, I'll get a tracin'!
Pin 5 of the MAX1044 is reading in the low positive volts, .64v I believe. Not good! That should be -9v, correct?
Here are some pics, if anything stands out as suspect or incorrect, please let me know!
Thanks again for this project.

(http://i304.photobucket.com/albums/nn165/candletears/2012-03-30065630-1.jpg)

(http://i304.photobucket.com/albums/nn165/candletears/2012-03-30065707.jpg)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on March 30, 2012, 04:19:12 PM
Yes, it should be about -9v. So that's one problem. Possible reasons are that you fed more than about 10v into the chip (maybe if you tried to power the pedal with a 12v supply?) or there's a short circuit somewhere in the charge pump area. If the chip feels hot or smells really funky, that would be relevant info as well.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: candletears7 on March 30, 2012, 05:23:37 PM
Ok thanks for the tip, still haven't got around to tracing it with the audio probe as yet... :icon_frown:
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: DrumKI on April 09, 2012, 12:02:08 PM
Do I have to solder both the top and bottom of this board?
Or just the underside (unmarked side)

Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Colonel Angus on April 09, 2012, 02:30:28 PM
If you have the MUSICPCB board, just the bottom. The holes are plated through, so if you want to solder the top side, say for offboard wiring, that will work just fine.

Just built mine last night and it fired right up, I'm really pleased with the PCB and the effect itself. I'll post a clip when I get it boxed up.

(http://i49.photobucket.com/albums/f251/divinec/Gristle.jpg)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Colonel Angus on April 10, 2012, 12:02:28 PM
Son of a b...   :icon_evil:This thing is a lot to stuff in a 1590bb. I managed to drill the holes for the PCB mounted pots, stuff the thing, and then broke the f-ing 6PDT rotary switch. I'll get it tonight... good thing I bought 5 switches  :icon_wink:
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Colonel Angus on April 12, 2012, 08:47:07 PM
(http://i49.photobucket.com/albums/f251/divinec/gristleizer.jpg)
(http://i49.photobucket.com/albums/f251/divinec/Gristleguts.jpg)
http://soundcloud.com/brian-moeller/gristleizer-guitar-demo (http://soundcloud.com/brian-moeller/gristleizer-guitar-demo)
soundclip has a lot of hiss, its the crummy power on the 3rd floor where my bench is. This is a pretty neat effect!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: candletears7 on April 17, 2012, 08:45:43 PM
Hi guys, is there a link or diagram for the rotary switch lugs corresponding to the numbered holes on the pcb. I may be missing something very obvious, but I'm only getting 2 different waveshapes. I think I've screwed this up somehow. The rest of the pedal works great, really cool sounds. Thanks.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Colonel Angus on April 17, 2012, 08:54:38 PM
http://musicpcb.com/wp-content/uploads/2010/09/Gristleizer-build-notes-updated-121709.pdf (http://musicpcb.com/wp-content/uploads/2010/09/Gristleizer-build-notes-updated-121709.pdf)
I used the continuity tester on my DMM just to be sure the switch worked the way I thought.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: candletears7 on April 18, 2012, 01:30:19 AM
Yes I have that thanks, but does lug one on the pcb correspond to lug 1 on the switch, as I followed the diagram...
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Colonel Angus on April 18, 2012, 09:26:43 AM
Lugs 1+6 go to the center poles on the switch - 2-5 connect to the rotary throws which make contact to lug 1, 7-10 connect to the rotary throws which connect to lug 6. The switch should be wired so that when lug 1 is connected to lug 2, lug 6 is connected to lug 7.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Ginsengbob on May 13, 2012, 04:19:25 PM
Taylor
Please help.
A guitar player hooked my Gristleizer up to 18v negative tip instead of 9v and screwed it up.
The rate light stays lit and doesn't blink and no sound comes out when the pedal is engaged.
Can you tell me what would have been messed up by the 18v and what to start testing or replacing?

thanks
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Colonel Angus on May 13, 2012, 04:22:05 PM
Start with the Max1044, it will fry at 10v
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on May 13, 2012, 05:08:39 PM
Colonel's right. That might be the only thing damaged. Other than that, if you used caps rated for less than 20v or so, they may have died.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Ginsengbob on May 14, 2012, 10:59:34 PM
Ok
Thanks
I will swap the Max1044 out first.
fingers are crossed
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Mtmattan on May 25, 2012, 08:09:58 AM
Hi guys, could REALLY use a bit of help with my build..

Everything worked 100% first time on my test rig :D
Great PCB and project!

After I had finished wiring up the jacks, power and put it in the enclosure I must have short circuited something.
The TL074 stared smoking and no sound.

I replaced the TL074 but no change - but I suspect I may have damaged this chip as well.
I did check all the solder joints and ensured none were touching - I did find one or two connecting bridges but as it worked fine first time I don't think these were relevant.

Currently:
The 7660 chip produces -9V on breadboard but only -4V tested with a DMM on the pcb.
I replaced the two 10uF capacitors but no no change.

If I use a battery to produce the -9V, the light flashes very dimly and only sound is the LFO ticks but no sound with the first TL074 and no flashing or ticking or sound with the second TL074.
Unfortunately I don't have another TL074 to test.


Would REALLY appreciate any advice, about to smash my head into a wall :)


Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Colonel Angus on May 25, 2012, 12:14:11 PM
based on the one 74 tick-y and the other no tick-y : the no tick-y one is probably dead. If you hear LFO tick then the 74 is working, or at least that was my experience ( i fried the maxx in mine and have had lots of quality debugging time with this circuit). I would recommend audio probe, see how far your signal is getting. Also if it worked on the bench and not after wiring the enclosure I would double check all the offboard wiring for continuity.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Globe Town Free Arts Lab on May 28, 2012, 07:15:16 AM
(http://i82.photobucket.com/albums/j279/lifewithbears/grisphoto.jpg)
(http://i82.photobucket.com/albums/j279/lifewithbears/grisgutsphoto.jpg)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Globe Town Free Arts Lab on June 28, 2012, 06:09:52 PM
Here's a clip of a casio keyboard going through my gristleizer
http://soundcloud.com/globetown/01-casio-new-pedal (http://soundcloud.com/globetown/01-casio-new-pedal)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Derringer on June 28, 2012, 06:39:00 PM
Here's a clip of a casio keyboard going through my gristleizer
http://soundcloud.com/globetown/01-casio-new-pedal (http://soundcloud.com/globetown/01-casio-new-pedal)

sweet

I love hearing how people are using their gristleizer
good looking build too !
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Colonel Angus on June 29, 2012, 08:26:05 AM
Good stuff! This pedal has more musical use that it appears at first glance. We managed to sneak it in on a couple guitar tracks for our new record. "Sounds like church underwater" is what my girlfriend said.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: ScurvyPat on July 15, 2012, 01:58:09 PM
Here's mine. Bent the sheet metal for the housing at work, had one of our guys weld the sides on, and slapped some rattlecan it. I included the speed control mod to use an expression pedal. Mine ticks a little more than I expected, so I put a cap in there to reduce it, but I found I liked a 1uf cap best rather than a 10uf. I put one of Taylor's other PCB's in there as well. The Christine does some nutty stuff and the Gristeizer really works well with it. Fired up the first time with no issues. Now I'm just waiting to get my hands on another Gristleizer PCB since my keyboard guy wants one too. (http://s134.photobucket.com/albums/q106/scurvypat/?action-view&current=102_4984.jpg)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on July 15, 2012, 03:24:59 PM
Here's mine. Bent the sheet metal for the housing at work, had one of our guys weld the sides on, and slapped some rattlecan it. I included the speed control mod to use an expression pedal. Mine ticks a little more than I expected, so I put a cap in there to reduce it, but I found I liked a 1uf cap best rather than a 10uf. I put one of Taylor's other PCB's in there as well. The Christine does some nutty stuff and the Gristeizer really works well with it. Fired up the first time with no issues. Now I'm just waiting to get my hands on another Gristleizer PCB since my keyboard guy wants one too. (http://s134.photobucket.com/albums/q106/scurvypat/?action-view&current=102_4984.jpg)

Cool build! I wasn't able to see your photo the way you posted it, but maybe this will work:

(http://i134.photobucket.com/albums/q106/scurvypat/102_4984.jpg)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: ScurvyPat on July 15, 2012, 10:17:53 PM
Oh my bad, it looks like I'll have to figure out how to post pictures properly on here. Thanks for the repost. :)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: glops on August 02, 2012, 11:25:28 PM
Here's mine. Bent the sheet metal for the housing at work, had one of our guys weld the sides on, and slapped some rattlecan it. I included the speed control mod to use an expression pedal. Mine ticks a little more than I expected, so I put a cap in there to reduce it, but I found I liked a 1uf cap best rather than a 10uf. I put one of Taylor's other PCB's in there as well. The Christine does some nutty stuff and the Gristeizer really works well with it. Fired up the first time with no issues. Now I'm just waiting to get my hands on another Gristleizer PCB since my keyboard guy wants one too. (http://s134.photobucket.com/albums/q106/scurvypat/?action-view&current=102_4984.jpg)

(http://i134.photobucket.com/albums/q106/scurvypat/102_4984.jpg)

Very nice!

Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: glops on August 02, 2012, 11:30:48 PM
I have a one spot powering my pedals and it always measures over 9 volts, I think up to 10.5 volts.  My Gristleizer stopped working
awhile back so I ordered another board.  I ordered a 9 volt regulator from small bear and was wondering that if I feed my onespot
through the regulator then into the 1044 will I be safe?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on August 03, 2012, 11:54:13 AM
That should be fine, but also if you use an LT1054 I believe it can handle several more volts input than the MAX1044, so with that you wouldn't need to worry about regulating and then doubling.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: papamatic on September 18, 2012, 02:43:05 AM
OK, I have built it and I need some pointers.

I have not dabbled much with oscillators/VCO's, so I have a hard time identifying what wave shapes the various rotary settings should be. Mainly I'm trying to identify which is supposed to be the triangle wave for tweaking. Also the other settings would be useful.

Other notes/observations: I had it kind of working before I boxed it up. However it seems to me that it lost some swoosh (for lack of a better description) after I boxed it up and added bypass etc. So I have to do some troubleshooting. Probably screwed something up. I have some high frequency sound going on in the background. I suspect it is from the power supply chip. I still have to trim back the length quite a bit on the wires running to the rotary switch, and that could help if there is some kind of oscillation going on. I also have a ticking sound which I see others have experienced. I'll check the posts more thorough for suggested fixes. This thing is definitely trebly - I concur with earlier posts on that point. It does give the guitar a serious spanky sound though. Spanks, bites and cuts. The way it is now it may have too many possibilities to enable quick adjustments between effects. I am toying with the idea of putting in a couple of "hardwired" settings - even if tweeking the settings to get all those very different sounds is much of the charm of this animal.

If anyone has some pointers on the initial wave shape settings question, that would be a good starting point for setting the trim pots and further trouble shooting, and I would be grateful.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: SlugBait on October 11, 2012, 07:33:53 AM
-
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: SlugBait on October 11, 2012, 01:00:57 PM
Hi everyone,

I mounted the major parts of my gristleizer already, however, as an new autodidact in the world of electronic, i have strong doubts about pots/switches/jack wing.

I made a scehma of my current state with missing wiring, if someone care to help, would be great!


(http://www.room856.com/gristleizer/GRISTLEIZER_build.jpg)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on October 11, 2012, 04:03:37 PM
The jacks in your picture look like the weird switching ones from Mammoth. Use a multimeter to fin which lugs are connected to the tip and sleeve and ignore the switch.

If you want to have true bypass on your effect, follow the link in the PDF file for true bypass switching. This will also show you how to wire the jacks up.

The "G" pad is ground. You need to connect all the grounds in your pedal to this point. That would be the negative lead from your power supply, the sleeves of your jacks, and the ground connection show in the true bypass wiring diagram.

Are you actually using a battery? If you wire it that way it will not work. You need to connect the negative to the G pad.

Welcome to the forum.  :) Also read the debugging links at the top of this page and "what to do when it doesn't work" in the top of the "building your own stompbox" forum.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: SlugBait on October 11, 2012, 08:27:04 PM
I get the point about jacks, battery and ground. I corrected everything.
I am missing the 3PDT to make the bypass then. I'm not sure i ca make it with the SPDT/SPST ?

Thanks
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on October 12, 2012, 05:55:37 PM
I don't think I understand your question - do you mean you are missing the information for how to do the bypass? It is located in the PDF file.

If you don't have a 3pdt, you can't do true bypass with an LED (unless you use the Millennium bypass or similar).
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: rainbowdoom on October 17, 2012, 04:02:41 PM
 Hi there, almost-first-time-poster here, longtime lurker. I didn't know where to post this because it has a few boards in it, but it feels more like super-modified Gristlizer than anything :)
 This box is four of Taylor's boards (Gristlizer, Echobase, Uglyface and Christine) all wired up to three switches to give 8 combinations of effects order. Only just finished it (haven't even painted the white knobs green yet...) so still getting a feel for it.
 Main reason for posting is to thank Taylor for these all the work he's put in on these PCBs- they are supreme quality and it all worked first time. Hugely grateful!!

(http://imageshack.us/a/img29/2781/dsc0242bn.jpg)
(http://imageshack.us/a/img13/2079/dsc0248jl.jpg)
(http://imageshack.us/a/img155/4858/dsc0246mv.jpg)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on October 20, 2012, 09:19:30 AM
Whoa! Amazing job. Really cool and funky.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: frrk on January 25, 2013, 12:31:34 PM
Hello everyone, I am a new-by in this forum and also in electronics.
i have purchased Taylor's gristelizer and finished populating it. After first test i am noticing a wrong behaviour.
At level pot on either ends, i have a whistle.
Also the signal seems not affected in the vca position.
In vcf mode the signal is very much affected and twisting the depth pot doesn't change the high pitched effect.
I may have some resistors value wrong and doubt about the 6n8 condenser couple (those are ceramics with 6.8 written).
the wires to the pots are quite long.
And the trim-pots are linear instead of log.
JFET is BF245 (with pins bent according to the original) which should be the right replacement for the 2n3819.
i use also an icl7660.
Out of those suspected components does anyone had fix similar problems before?
Last; while un-soldering the tl074 some tracks ends got burned away.
At the moment the lfo doesn't work (but it did work when first tried).
Anyone could list or draw the connections points to the tl074
If i do it from the schematics i fear to forget some points and mess some other things that are working.
Please, help me debug this device. Would be great.
Thanks in advance.
Frrk
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Gila_Crisis on March 14, 2013, 05:41:26 AM
I have a question I just finished building one with the pcb from musicpcb.com.
everything works really fine and I'm enjoy it a lot.
I was only wondering about one thing, the triangle wave setting is a bit weaker sounding compared to the other waveforms.
is that normal?
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Ginsengbob on April 25, 2013, 03:55:42 AM
Would it be ok to substitute a 6.2k resistor for the 6.8k resistor in the gristleizer ?



Thanks
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on April 25, 2013, 10:56:59 AM
Yes.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Salvador on May 22, 2013, 07:45:57 PM
Building 5 gristleizers currently. Have tested 3, 2 of them are "functional". An issue I am having is what seems to be a circuit-wide voltage offset. Reading +10.5 to 13v and -7.5 to 5v. Have tried max1044, icl7660 and divided 18v circuit. Is this typical? Has anyone else run across this issue and maybe remedied it? I have been unable to properly calibrate and am guessing this is a reason why.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Salvador on May 22, 2013, 08:12:12 PM
I suppose that may be a bit cryptic. The issues that led to the voltage measuring was what seems to be an instability in the circuit. In vca mode it almost seems that the effect is parallel with the signal rather than effecting it. A strong pulse can be heard but does not necessarily translate to the material itself. Tuning of shape and offset seems to only affect the triangle wave-shape. This is most apparent in vcf mode. Triangle can be set to the point of distortion and really sounds more like a saw wave. Seems like this could be from the voltage disparity? Any ideas are more than welcome and appreciated!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Salvador on May 24, 2013, 01:19:45 AM
Turned out I had a bad JFET. Still a difference in voltages when idle which seems odd, but then I'm not so familiar with this circuit and a bit of a novice to boot!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: bcalla on June 07, 2013, 09:42:11 AM
I finally finished mine.  I was actually done in January, but I shorted the LED when I boxed it & didn't get around to finding the problem and fixing it until yesterday.  :icon_frown:

It sounds great, but I did notice a problem.  With the speed set to very slow it is possible to hear the wave shapes (I don't have a scope).  It appears that the rotary switch labels on my enclosure are reversed.  Could the fix to this be as simple as reversing all the wires on my rotary switch?  That seems easier than refinishing the enclosure.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: _dB on August 29, 2013, 07:29:44 PM
Just finished building the Gristleizer from MusicPCB. 

Waveforms look good on the scope. I was worried I had blown the MAX1044 (pugged it into a 16V wart by mistake) but the voltage still reads +9/-9V out of the MAX, so I think it survived.

If anyone else has the pedal, I am wondering if the following is part of normal behaviour:

- In VCF mode: is it supposed to be so high pitched? There is almost no low end; very "trebly", kind of painful to listen to.
- BIAS past 12' oclock results in pretty intense distortion in both VCF and VCA. Is that how it's supposed to work?

In VCA mode, should the DEPTH affect the sound with BIAS all the way down?   

Thanks!



Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Johnnyboy on February 04, 2015, 08:52:42 AM
Just completed the Gristlizer, over here in the UK, using Taylor's board. Thanks Taylor, excellent quality PCB. A couple of years ago, I built the circuit from the original Practical Electronics magazine article but it was pretty hopeless. Now that the 741's have been replaced with modern chips in the circuit, it's successful. Not boxed it yet, as only just finished the wiring etc. Not suffering from the dreaded 'clicking' at all. I'm running a homemade function generator (Maplin kit) though the input with good results.
If you mount the Depth control on the board, you can pick up an extra Ground point from behind the pot ( LH hole, looking at front of controls), should you need it.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: yeahyeah on June 01, 2016, 03:31:33 PM
Any tips/mods for getting a slower lfo on minimum speed settings?

I'm finding it hard to hear the difference between waveform settings on all but the slowest speeds. I have cal'ed all shapes on scope and everything looks good and sounds gristle-y.

thanks!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on June 01, 2016, 07:46:08 PM
You can make the speed range of the LFO slower by changing the value of C1 - it's the 470n cap to the left of the TL074. Double the capacitance value would make the LFO half as fast, etc. You can even have two different ranges by using a toggle switch to swap between cap values. That would be good if you still want to keep the current fastest speeds.

It's been a while since I listened to this circuit, but I wonder if the waveforms are getting altered because of the Bias setting. I'm no FET expert but to my knowledge, the "linear region" is not really that linear. So the LFO could present a perfectly linear triangle, for example, and if the bias is not quite right, the transistor responds as if it's a lumpy asymmetrical sine-like wave.

But, that "wrongness" that results from setting the Bias to the "wrong" spot is part of the charm of the Gristleizer, and it's why the board lets you bring it out to a panel-mounted pot. There should be an area on the Bias knob that gives reasonably accurate waveforms, although it has to be said that none of this circuit's sections behave like ideal modern versions would.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: geocontrol on September 05, 2016, 06:08:51 AM
Hi, Can I ask a real newbie question, how do I connect up jack sockets to this PCB? I'm right in thinking I could connect a eurorack style jack socket to the Input and the Output, but only one hole in the PCB, guessing I need to earth the socket to some other common earth on the board?

Sorry if this is really basic, just getting started and realising the limits of my knowledge real quickly..

thanks

mark

Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on September 05, 2016, 12:27:00 PM
Yes, you would connect the tip connection on your jacks to the input and output pads on the PCB, then connect the sleeve (ground/earth) pins from the jacks to each other, and to the ground pad on the board. Basically you just need to make sure all of your grounds connect to each other.

Technically you can use the front panel to connect grounds in a euro module, if the panel is metal. But, I don't recommend it because you will get intermittent connections if the jack ever loosens.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: geocontrol on September 07, 2016, 07:31:57 AM
Ah, Thanks Taylor, got it. I'll post a pic and update once its done :)
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: TheLoneRoger on April 11, 2017, 04:45:37 AM
Hi,
 Ive recently started re-building some old projects I started back in the '80s, which includes an E & MM Spectrum synth (x2!) and a couple of original Phonosonics boxes, one of which is the Guitar Effects Pedal (go to love PE's understated project names!) a.k.a. Gristleizer.

 Anyway, I was delighted to find this thread, but after reading the first 4 pages, my eyes are getting sore, so I was wondering if there is anywhere a summing up of the the various essential mods so I can bring mine up to date without having to plough through another 12 pages?

 Also, has anyone adapted one for 15V rails? Ill be using mine with my Digisound/Spectrum modular, which  uses +/- 15V supplies.
Cheers
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: disorder on August 08, 2017, 03:01:25 PM
Just built mine up, sounds great but I'm having trouble with the square wave setting on the rotary switch. I don't get any modulation on that switch setting. My triangle wave looks good on a scope as does the ramp up and ramp down, I can hear those as well. But square wave is not getting to the wiper of the depth pot. The weird thing is if I probe on lug 3 of the depth pot and set the depth pot to minimum, I can see the square wave. As I slow increase depth the square wave disappears from lug 3. The square wave is sensitive to impedance to ground. What could cause this? Any suggestions? Thanks!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: disorder on August 08, 2017, 03:55:28 PM
SOLVED: Theres an optional 10uF cap spot on the pcb you can populate to help reduce "ticking". Its not on the schematic but it's from the DEPTH pot wiper to ground. My guess is during the fast transients of the square wave the opamp has a hardtime keeping up with the charge requirement. Not sure. I was seeing another issue that was caused by the optional de-tick cap as well. The rampup wave would almost double in amplitude when depth pot was set to max. My guess is that with the wiper connected to lug 3 there is no longer an series resistance between that optional 10uF cap and the waveform/oscillator circuitry making it act funky. Again... cap is asking for too much current too fast or something.

Just keep that in mind...
Title: Gristleizer vca doesn't work, but vcf does.
Post by: lulu_joe13 on September 26, 2017, 10:36:02 PM
I am trying to fix my rather road weary gristleizer. The vcf is working fine but I get no output when I switch to vca? Any suggestions of how to trace this. I have a mult and an audio probe but looking at the schematic I can't figure out which traces and components are the vca. Any help would be much appreciated. JoeF.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: BetterOffShred on September 27, 2017, 11:21:20 AM
So I've finally built my Gristleizer board, and hooked up all the pots and rotary switching as per the wiring diagram in the build document.

I've used a 2N3819 JFET  and 2N3904 and 2N3906 as indicated
7660 power chip (measured +9.35v and -9.27v) outputs
1N34A diodes
TL062   (Started with TL072)
LM324  (Started with TL074)
3P4T switch
Stock Pot values C100k for Bias
100k Trimmers for "Shape" and "Offset"

So it fired up and I get sound through it, the volume works, the Bias knob changes the color as it's moved, the LED flashes and changes rate with the speed pot, and there is some tick, which goes away when Depth is turned all the way down (which I assume means the depth pot is actually working) but other than that there is very little actual Tremolo type sounds.   The DPDT for VCF/VCA also definitely changes the sound, one being more trebley as reported elsewhere, but still no real pulsing sounds.   
I tried flipping my 2N3819 around and it seems to have no effect really.   The 3P4T selector has minimal effect on the sound, though some is noticeable with what little tremolo sound I can hear.  I used the Meter to identify the A)1-4 and B)1-4 and wired according A-1 B-6 as per the drawing provided. 

So am I just needing to find a real sweet spot on the shape and offset trims here? Or does something sound fundamentally wrong?  I don't think I will have access to a scope, so I'm not sure if that's an option currently.  Everything else I've read, people plugged it in and had choppy tremolo goodness on 3 of the 4 modes, having to really only dial in the triangle wave.  So plugging mine in and having barely noticeable tremolo on any setting which doesn't seem to get better with crude turning of the shape and offset trimmers audibly at all concerns me that something else is jacked up.   I know the LFO is working because the LED is blinking and I get tick that goes away..   Anyway  I'm open for some suggestions if anyone has any!    ;)
Thanks
Title: Re: Gristleizer vca doesn't work, but vcf does.
Post by: Taylor on September 27, 2017, 01:33:22 PM
I am trying to fix my rather road weary gristleizer. The vcf is working fine but I get no output when I switch to vca? Any suggestions of how to trace this. I have a mult and an audio probe but looking at the schematic I can't figure out which traces and components are the vca. Any help would be much appreciated. JoeF.

The VCA/VCF switch just switches between a cap and a resistor, and in VCF mode adds another cap in a feedback loop. The parts are the 6n8 caps and 47k resistor directly next to pin 6 of the TL072, right side of the board. So your issue probably lies in that resistor, or the switch wiring.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on September 27, 2017, 01:43:52 PM
So I've finally built my Gristleizer board, and hooked up all the pots and rotary switching as per the wiring diagram in the build document.

I've used a 2N3819 JFET  and 2N3904 and 2N3906 as indicated
7660 power chip (measured +9.35v and -9.27v) outputs
1N34A diodes
TL062   (Started with TL072)
LM324  (Started with TL074)
3P4T switch
Stock Pot values C100k for Bias
100k Trimmers for "Shape" and "Offset"

So it fired up and I get sound through it, the volume works, the Bias knob changes the color as it's moved, the LED flashes and changes rate with the speed pot, and there is some tick, which goes away when Depth is turned all the way down (which I assume means the depth pot is actually working) but other than that there is very little actual Tremolo type sounds.   The DPDT for VCF/VCA also definitely changes the sound, one being more trebley as reported elsewhere, but still no real pulsing sounds.   
I tried flipping my 2N3819 around and it seems to have no effect really.   The 3P4T selector has minimal effect on the sound, though some is noticeable with what little tremolo sound I can hear.  I used the Meter to identify the A)1-4 and B)1-4 and wired according A-1 B-6 as per the drawing provided. 

So am I just needing to find a real sweet spot on the shape and offset trims here? Or does something sound fundamentally wrong?  I don't think I will have access to a scope, so I'm not sure if that's an option currently.  Everything else I've read, people plugged it in and had choppy tremolo goodness on 3 of the 4 modes, having to really only dial in the triangle wave.  So plugging mine in and having barely noticeable tremolo on any setting which doesn't seem to get better with crude turning of the shape and offset trimmers audibly at all concerns me that something else is jacked up.   I know the LFO is working because the LED is blinking and I get tick that goes away..   Anyway  I'm open for some suggestions if anyone has any!    ;)
Thanks

It sounds like all of the sections are basically working, except perhaps the transistor itself. We know that your LFO section is oscillating, and the Bias knob changing the sound indicates that if the transistor were working right, you'd have a cyclic effect. It's possible that it's down to getting the trimpot settings tuned right, because if the LFO signal getting to the FET is too far offset for example, it will have a small amplitude and not really sweep the VCA/VCF enough to give an audible effect.

I might try a new 3819 to eliminate that as the issue, and maybe just reflow the solder joints on the diode and passives surrounding the FET, in case something is shorted there that's keeping the LFO from modulating the FET.
Title: Re: vca/vcf now working
Post by: lulu_joe13 on September 27, 2017, 02:15:29 PM
Thanks Taylor! Fantastic pcbs and support! Love my Gristllzer!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: BetterOffShred on September 27, 2017, 02:18:51 PM
It sounds like all of the sections are basically working, except perhaps the transistor itself. We know that your LFO section is oscillating, and the Bias knob changing the sound indicates that if the transistor were working right, you'd have a cyclic effect. It's possible that it's down to getting the trimpot settings tuned right, because if the LFO signal getting to the FET is too far offset for example, it will have a small amplitude and not really sweep the VCA/VCF enough to give an audible effect.

I might try a new 3819 to eliminate that as the issue, and maybe just reflow the solder joints on the diode and passives surrounding the FET, in case something is shorted there that's keeping the LFO from modulating the FET.
Thanks for looking at my post!   :icon_mrgreen:

I have 3, and I actually got out of bed last night after laying there a while thinking about it and tried another one of them, with the same results.   I have one left I'll try when I get off work, and then a load of J201's and 2N5457's etc (with different pinouts of course) which I can try if that one doesn't work, hmm I even have some MPF102's.  I'll put on the reading glasses and reflow all the solder on the back of the board as well, though it looks pretty good to me. 

This is my first PCB build, and I put everything on top, where the values are marked, and soldered the back, that's correct right?  :P  Built tons of stripboard layouts, but never a PCB
And then looking at the board with the label side up, pot connections at the bottom, I hooked the pots up as:
321  321  321  321   
I had them the other way before (123) and the volume and speed worked backwards so I assumed the others did too. 
Also, right above the pads for the trim pots (outside the white box) is another hole which seems to be linked to the wiper of the trim pad? Is that the case for all 4 locations for using a larger variety of trim pot?  I used the small variety and just soldered to the holes inside the box.   

EDIT:  Another thing I noticed was that the "Minimum" speed of my LFO seems much faster than videos I've watched, and I think a few pages back it was indicated this speed was tied to the 470n cap right next to the TL074.   I definitely have a 470 in there (474J100), I took tons of pictures so I've basically been agonizing over every component value which I checked every single one, including resistors.. ugh.

Thanks again for looking.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on September 27, 2017, 02:59:01 PM

This is my first PCB build, and I put everything on top, where the values are marked, and soldered the back, that's correct right? 

Yep, that's right.

Quote
And then looking at the board with the label side up, pot connections at the bottom, I hooked the pots up as:
321  321  321  321   
I had them the other way before (123) and the volume and speed worked backwards so I assumed the others did too. 
Also, right above the pads for the trim pots (outside the white box) is another hole which seems to be linked to the wiper of the trim pad? Is that the case for all 4 locations for using a larger variety of trim pot?  I used the small variety and just soldered to the holes inside the box.   

That's right, the extra hole is just to accommodate different types of trim pot, and it sounds like you've got the pots in the right way now.

Quote
EDIT:  Another thing I noticed was that the "Minimum" speed of my LFO seems much faster than videos I've watched, and I think a few pages back it was indicated this speed was tied to the 470n cap right next to the TL074.   I definitely have a 470 in there (474J100), I took tons of pictures so I've basically been agonizing over every component value which I checked every single one, including resistors.. ugh.

Could you post a photo of your build? Maybe there will be something that pops out as a problem.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: BetterOffShred on September 27, 2017, 03:18:40 PM
Could you post a photo of your build? Maybe there will be something that pops out as a problem.

(https://s26.postimg.org/e4h8a8nw5/Grist1.jpg) (https://postimg.org/image/e4h8a8nw5/)

(https://s26.postimg.org/yd4lvyn79/Grist2.jpg) (https://postimg.org/image/yd4lvyn79/)
Yes I know everything is too long, I don't have access to my drill press so I figured Id "Squid" it up and try it out, though I'm not really that great at making neat wiring to be honest!
thanks!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: BetterOffShred on September 27, 2017, 08:38:46 PM
Well I reflowed solder and double checked components, tried a j201 with legs bent to match socket, that didn't work either.  I checked voltages at all places on the board that are shown in the schematic and I have matching values in all locations. 

One thing I've noticed is that as I leave it plugged in, the "minimum" speed becomes faster and faster as if I'm slowly turning the knob up but I'm not.  This is really strange as I indicated earlier I thought the minimum speed was way faster than the other videos I've watched.  So yeah. I'm kind of blown away right now.  Not sure what to try. I think I'll try a different 470n and maybe some 1N4148 diodes instead of the germaniums.. I can post crazy high resolution pics of everything if anyone is willing to look.  This has me at a loss
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: BetterOffShred on September 27, 2017, 09:00:56 PM
Alright so my 2N3819 is not the same Pinout as other units .. I threw it on my mega328 tester and figured out what was what.  So now I got chop, but the rate is still way fast after I put in an 800n, and it still speeds up over time.
Title: adding a vc input
Post by: lulu_joe13 on September 28, 2017, 12:28:31 PM
@Taylor. OK. So I have also built your Tap Tempo Tremelo and added a 5v CV out. I am wondering if I can add an input to the Gristlizer to use this instead of the internal oscillator? I want to switch not sum.
 And while we are at it. Where would I grab the internal oscillator to send it out.
 Covered previously? Tx. JoeF.
Title: Re: adding a vc input
Post by: Taylor on September 28, 2017, 02:08:07 PM
@Taylor. OK. So I have also built your Tap Tempo Tremelo and added a 5v CV out. I am wondering if I can add an input to the Gristlizer to use this instead of the internal oscillator? I want to switch not sum.
 And while we are at it. Where would I grab the internal oscillator to send it out.
 Covered previously? Tx. JoeF.

Assuming you've added filtering on the TAPLFO's PWM output to get your CV out, you could swap between that and the wiper of the depth pot on the Gristleizer. Off the top of my head I don't remember the scaling of the LFO coming out of the depth pot, so the two LFOs may or may not sweep through the same range when you switch between them.

To send gristleizer's LFO out, you'd just take it from the depth pot wiper, and I'd probably add an opamp buffer so that whatever you're modulating with it doesn't affect it oscillating.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on September 28, 2017, 02:10:45 PM
Alright so my 2N3819 is not the same Pinout as other units .. I threw it on my mega328 tester and figured out what was what.  So now I got chop, but the rate is still way fast after I put in an 800n, and it still speeds up over time.

Do your +9V and -9V rails stay stable over time? If something is weird with the power supply it might cause that drift.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: BetterOffShred on September 28, 2017, 02:21:39 PM
Alright so my 2N3819 is not the same Pinout as other units .. I threw it on my mega328 tester and figured out what was what.  So now I got chop, but the rate is still way fast after I put in an 800n, and it still speeds up over time.

Do your +9V and -9V rails stay stable over time? If something is weird with the power supply it might cause that drift.
Thanks for the reply Taylor  :) I'm sure I'm getting annoying, but this is really weird!  I've built tons of effects and I'm no slouch with a soldering iron, which of course are famous last words I'm sure!  That being said I'm beginning to suspect my D1 (the schematic has it as D1, but it's D2 on the board itself) is damaged or something.  If it was not operating correctly it could be allowing both sides of the speed cap to approach the same potential, thus speeding up over time?   

The 9v +and- were consistent every time I checked them while I had it plugged in for like 10 minutes.   If the Diode doesn't fix it, I'll leave it plugged in for like an hour later tonight and record before and after values.   Thanks again for looking,  I really want to gristle  :icon_mrgreen:
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: BetterOffShred on September 28, 2017, 08:46:46 PM
Yeah totally that diode.  I went to pull it out and it was broken in half.  Luckily some D9E's I ordered for my Laika and/or Harvey Dent board I bought from Dino (thanks boss) arrived today from Bulgaria.  So I sockets one of those and it's amazing.   I'll spend a little time dialing it in but it's working great!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on September 29, 2017, 06:50:30 PM
Great to hear! Weird about the broken diode, there's no significant current flowing through there, but I guess that's glass for you.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: BetterOffShred on September 29, 2017, 11:22:35 PM
Yeah I threw the DVOM on the D2 and it was like -2.1v on one side and like -1.5v on the other.  Then the suspect diode.. -7.8v one side .. 0.0v the other.  So yeah. That cap was slowing reaching the same potential on both sides raising the speed.  It sounds really great now.  I tried for funsies to get a 2n5457 to drive the circuit but it wouldn't.  The 2N3819 sounded good so why mess with success.  I have a little tick in the square wave setting but I dialed in the triangle really lush and the ramps both sound super great.  I haven't tried any of the detick stuff yet and I have long leads on everything as I was troubleshooting it so I'm moving forward with boxing it up.  I love it.
Title: Re: Adding CV in and out
Post by: lulu_joe13 on September 30, 2017, 09:10:47 PM
Tx again Taylor. JoeF.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: peAk on October 11, 2017, 10:04:09 AM
Hey Taylor,

Just finished up my Gristleizer and everything is working nicely.

My only question is, and I ask this even after reading through these 17 pgs, what was the end result of getting rid of the LFO ticking? From what I have read this is what I have came up with:

1. Use the optional 10uf cap

2. Run a large electro cap across the +/- TL072 (Is this the same as using the optional 10uf cap?)

3. Use shielded cable for the input/ouput

4. Disconnect the LFO LED

The only one I have tried is the optional 10uf cap and I seem to be getting some ticking still. Now mine is still unboxed so I assume some of the ticking could go away with it boxed?

Anyway, what are your thoughts/experiences with this and what would you say has been the most successFUL with eliminating the LFO tick?

Thanks!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: BetterOffShred on October 11, 2017, 10:26:43 AM
I believe the earlier suggestions for a "De-tick" cap were on pins 4 and 11 of the TL074, which I tried on my build and had no luck with.   It says it needs to be fairly large, so I just got some 470u's in that I'll try again.  I had a noticeable tick reduction by going to a LM324 and a TL062, but it also required me to readjust my wave shape and offset trimmers.   It was actually easier with the LM324.  Mine now only ticks slightly on the Square wave setting, and I haven't shortened any of the wires or used shielded cable yet as I've been extremely busy with work and haven't had any soldering iron time.   The other 3 settings are so damn good I don't even care about the square wave setting.  I have a few different Trem's and the VCA stuff is so nutty this pedal just rocks.   Hope that helps a little!
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on October 12, 2017, 10:00:07 PM
BetterOffShred's suggestions sound good to me, but regarding your number 2, the "de-tick" cap on the board is connected to the LFO signal going to the FET transistor so that's different from power supply bypass caps.

I think it would be a good idea to put 100n caps from both the positive and negative power pins of the TL072 and TL074, going to ground. You want these caps to be as close as possible physically to the power pins, and with the leads trimmed as short as possible.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: BetterOffShred on October 12, 2017, 10:14:42 PM
I tried a 470uf on 4 and 11, no dice.  I'm pretty happy with this the way it is, but I'll try the 100n's. I think the circuit is what it is, and I really enjoy it's overall sound. I've seen some layouts with everything split Into single opamp but reports are that they still tick here and there.

Get those wires as short as possible and shield the in and outs to/from everything, making sure to ground only one end of the shielded cable.
Title: Got a oscilliscope
Post by: lulu_joe13 on November 16, 2017, 12:20:50 PM
Taylor, perhaps this is a question beyond good support but if you have time can you answer or send me where there is some instruction. I just got an oscilloscope and want to use it to tune my Gristleizer. Where do I attach the test lead on the PCB to adjust the shape or is it on the leg of trim trim pot and ground? What about for the offset? Thanks as always for any help. JoeF.
Title: Re: Anybody build their Gristleizer yet, comments on it?
Post by: Taylor on November 16, 2017, 12:37:02 PM
For both, you can view the LFO waveform by probing at the center lug of the Depth pot.