It's my own Ge fuzz creation, borrowing of course from many other sources, thanks Gus for the awesome tone stack!
Anyway, it sounds great on my breadboard but I want to know if any of you can spot any redundancies, overkill, important missing parts or improvements that can be made.
I created it through a lot of trial and error so a lot of changes were made along the way and this is where I ended up liking it.
(I just realized I forgot the 1M pulldown resistor in my drawing but I would not (hopefully) forget to include it in the soldering stage.
Also, let me know if any or all of it looks familiar to you ;)
Thanks!
(http://i63.tinypic.com/1zxwled.png)
looks good Ben
One of the longest lasting pedals on my board is a MKII variant. They are open to lots of fun mods and just sound good!
The 0.1uF from emitter to ground on Q3 is a new one for me ... suppose you're always getting some top-end boost that way even with the 1k gain rolled all the way down. Cool.
Diodes are silicon?
Is everything biasing up nicely for you? No need for trim pots?
Quote from: Ben Lyman on November 21, 2015, 02:40:54 AM
It's my own Ge fuzz creation, borrowing of course from many other sources, thanks Gus for the awesome tone stack!
Anyway, it sounds great on my breadboard but I want to know if any of you can spot any redundancies, overkill, important missing parts or improvements that can be made.
I created it through a lot of trial and error so a lot of changes were made along the way and this is where I ended up liking it.
(I just realized I forgot the 1M pulldown resistor in my drawing but I would not (hopefully) forget to include it in the soldering stage.
Also, let me know if any or all of it looks familiar to you ;)
Thanks!
(http://i63.tinypic.com/1zxwled.png)
Just curious why you have the voltage divider for Q1C? Essentially its 10K to C, 100K C to ground, which would give approximately 8.2V with 9V on the rail. Are you simply trying to attenuate the signal by 50%? If you want signal attenuation, you might consider a DC isolated pot instead.
Quote from: Derringer on November 21, 2015, 09:52:10 AM
...The 0.1uF from emitter to ground on Q3 is a new one for me ... suppose you're always getting some top end boost...
Diodes are silicon?
Is everything biasing up nicely for you? No need for trim pots?
I really don't know what I'm doing here but yes, the lowest gain setting sounded better to me with that .01 cap there, it made an otherwise muddy, unusable tone into a great sounding crunchy, rhythm-like or bluesy OD lead tone.
Diodes are still being swapped around a bit but I'm mostly liking the HP Motorola Si diodes from the surpluss store score.
I haven't even checked voltages because it just sounds perfect and I haven't even moved it back up off the floor to work on it in a couple days. If I get time later I'll check it out and see where it's at. No need for trimmers yet, Q2 and Q3 were dialed in using Joe Davissons FF calculator according to the gains I measured.
Quote from: Cozybuilder on November 21, 2015, 10:20:55 AM
Just curious why you have the voltage divider for Q1C? Essentially its 10K to C, 100K C to ground, which would give approximately 8.2V with 9V on the rail. Are you simply trying to attenuate the signal by 50%? If you want signal attenuation, you might consider a DC isolated pot instead.
Thanks Russ, that is one of the things I was hoping to get advice on. Like I said, I don't know what I'm doing here but it sounds good so I'm afraid to experiment further without some guidance. After I used Joe Davissons FF calculator, I added a Ge volume booster stage in front (Q1) based on the EHX LPB-1. It added the right amount of boost when the pot was about 1/2 way so, not knowing anything else to do, I took out the (100k) pot and put in two (51k) resistors.
:icon_question: Is there a better way to achieve the same goal without using a pot? I really don't want four knobs on this box, I'm always hesitant to do even 3 knobs on anything 😬
nothing wrong with attenuating the signal there. I did pretty much the same thing in my mk2 design ;)
Do you have a multimeter handy that you can check the voltage of the collector from the 1st transistor?
If it's somewhere between 3 and 6 volts, and it sounds good to you, I'd think you're good to go.
Otherwise, you might want to add a capacitor between the collector and the 51K resistor to isolate the DC voltage to the collector, re-measure it and then mess with either the 10K resistor or the 390R resistor (or both) to get that voltage somewhere between 3 and 6 volts ... 4.5 volts being the ideal clean boost voltage.
I've had experiences where, I breadboard everything, it sounds great with whatever biasing arrangement I made, then I build it, play it for a week and all of a sudden start noticing some gating or cutoff that I hadn't notice before.
You're a lucky guy Ben with these two guys on it and Gus too. Like the tones stack.
Watching and waiting a sample maybe?
Quote from: Derringer on November 21, 2015, 01:51:35 PM
...you might want to add a capacitor between the collector and the 51K resistor to isolate the DC voltage to the collector, re-measure it and then mess with either the 10K resistor or the 390R resistor (or both) to get that voltage somewhere between 3 and 6 volts ...
Yes, I have a DMM so I will look into that ASAP. I honestly didn't even know that I had all that stuff laid out like that until I inspected it to draw up the schematic. If I decide to adjust the voltage to Q1, is that 4.7uF ok right there or should I just move it in between the Q1c and 51k?
Quote from: Kipper4 on November 21, 2015, 02:04:24 PM
You're a lucky guy Ben with these two guys on it and Gus too. Like the tones stack.
Watching and waiting a sample maybe?
Yes indeed, I feel SO lucky to be getting help from any and everyone at this forum! I'll try to make a short video later.
Cool design! I'd normally expect a coupling cap between Q1C and the 51k series resistor, but the voltage at Q1C will be dominated by the 10k to 9v and the CE resistance (10kish) rather than the 102k to ground so I don't see it screwing up the biasing. If it sounds good, box it up.
... except your 4.7uF cap is backwards. Q2B should sit at .3v or so, while the other end of that cap should have 2-3v at idle (Q1 collecter at 4.5v-ish divided in half by 51k resistors). Sometimes electrolytics can get leaky (or generally behave oddly) if they're reversed, so flip it on the breadboard and make sure it sounds the same with that cap inserted correctly. You really shouldn't leave an electrolytic reversed, so hopefully none of the sound you like is caused by a badly-behaving cap. ;)
Quote from: Keppy on November 21, 2015, 05:50:21 PM
...I'd normally expect a coupling cap between Q1C and the 51k series resistor...
...your 4.7uF cap is backwards...
Thanks Keppy, fixed the 4.7uF and still love the sound... so that's the good news, I like the way it sounds... here's the bad news:
EDIT- New readings with 9v wall adapter:
Q1
c. 1.41
b. 0.49
e. 0.32
Q2
c. 0.73
b. 0.11
e. 0.00
Q3
c. 5.96
b. 0.73
e. 0.56
any suggestions? box it up because I like it? 🤔
The posted schematic cannot produce the numbers shown. For example, Q2C is shown connected directly to Q3B, but you recorded them as different readings. Also, Q3B is above E, which shouldn't be possible, although I say that with little confidence because I haven't spent a ton of time experimenting with (potentially) leaky germanium transistors.
Whatever. The voltage feedback biasing maintains itself pretty well, so as long as Q3 collector is reasonable (it is), Q2 and Q3 should be fine.
Q1 is biased pretty hot, which should make it pretty asymmetrical, and lack of headroom in that stage doesn't matter much with all the gain behind it. That should be fine as well.
The only REAL problem I see is making sure you build what's actually on the breadboard. I say, double- and triple-check your schematic against what's on the breadboard to make sure you got it right. Then box it. Then play it a lot, because it sounds great!
Quote from: Keppy on November 21, 2015, 07:57:56 PM
The posted schematic cannot produce the numbers shown. For example, Q2C is shown connected directly to Q3B, but you recorded them as different readings. Also, Q3B is above E, which shouldn't be possible...
You're right, thanks! I think I was just careless when I did that. See my new readings above, they are all a little different because I used a one-spot instead of a battery but I'm pretty sure they are accurate this time.
I got the transistors from these boards I pulled from a 1967 Ampex Procamp processing amplifier.
It's loaded with Ge Texas Instruments and Philco transistors, about half PNP and half NPN. Lots of Ge diodes too, those sounded great but I think my mysterious HP/Motorola Si diodes sound a little better in this circuit.
(http://a64.tinypic.com/dxn3tg.jpg%20(144%20KB))
what is that flying saucer on the heatsink, and what is the "stat-tran" directly above the double-twirled diode? another trivia Q?
Overall I think its looking good. If you can up the voltages on Q1 to (C= 3 to 5V) and (B= 1 to 2V), and for Q2C to about 1.5V, leaving Q3C about 4-6 V, I think you'd be real happy.
Which transistors did you wind up using?
look at Q2 collector note R10 VR2.
http://moosapotamus.net/ideas/acoustic-360-bass-fuzz/#more-263 (http://moosapotamus.net/ideas/acoustic-360-bass-fuzz/#more-263)
and http://www.diystompboxes.com/smfforum/index.php?topic=105024.msg944241#msg944241 (http://www.diystompboxes.com/smfforum/index.php?topic=105024.msg944241#msg944241)
I think the decay control is something to experiment with
Quote from: duck_arse on November 22, 2015, 10:00:35 AM
what is that flying saucer on the heatsink, and what is the "stat-tran" directly above the double-twirled diode? another trivia Q?
I dunno about the "Stat Tran" Duck.
Printed on it is:
PULSE ENG. PE-1983 .5MH,1:1:1 STAT-TRAN PAT NO. 2,885,643 6333P
It has 3 legs at each end, numbered (on the board) 1,3,5 and 2,4,6
The Flying Saucer is a solid gold Philco 2N600 protected by an elaborate heat sink/roll cage and gold leads insulated with clear plastic tubes.
Quote from: Cozybuilder on November 22, 2015, 10:52:08 AM
Overall I think its looking good. If you can up the voltages on Q1 to (C= 3 to 5V) and (B= 1 to 2V), and for Q2C to about 1.5V, leaving Q3C about 4-6 V, I think you'd be real happy.
Which transistors did you wind up using?
Thanks Russ, any trick to upping the voltage? Maybe adjust my whack-a-doo voltage divider 51k to ground?
I swapped Q1 out with some others, sound didn't change but I got some new voltage readings:
Q1
c 2.89
b 0.39
e 0.24
Q2
c 0.80
b 0.12
e 0.00
Q3
c 5.47
b 0.80
e 0.65
They are all Texas Inst. 2n1304 npn
Quote from: Gus on November 22, 2015, 11:11:28 AM
look at Q2 collector note R10 VR2.
http://moosapotamus.net/ideas/acoustic-360-bass-fuzz/#more-263 (http://moosapotamus.net/ideas/acoustic-360-bass-fuzz/#more-263)
and http://www.diystompboxes.com/smfforum/index.php?topic=105024.msg944241#msg944241 (http://www.diystompboxes.com/smfforum/index.php?topic=105024.msg944241#msg944241)
I think the decay control is something to experiment with
Thanks again Gus, I will look into that. I would rather not add anymore knobs to this and I really love that tone stack so I think 3 knobs only on this one.
I wonder if an internal trim pot would be a good place for the gate control?
:icon_question: The only other thing I am wondering about is power filtering. The little 1nF cap seems to lower some of the noise but I was considering a very small resistor in series with the +9v right before or after the protection diode. Any thoughts on that?
Ben- I'd try getting rid of that voltage divider first, this is easily done by just sticking a cap between Q1C and the first 51K, leaving the rest leading to Q2B as is, {or stick a 100K trimmer (or pot) in place with the wiper to the 4u7, and adjust to your liking, replace with a pair of resistors that are close to whatever that pot setting divides out to, or leave the trimmer (pot) in place}. The next thing is to up the 47K from ground to Q1B to about 100K. Measure- you should be closer on Q1 B and C.
Q2, I'd try 39K on the collector- that should get you closer to 1.5V, or even 33K.
sounds pretty righteous in your clip!
Is there any ducking when you hit the strings hard? If not, I think you're pretty good.
If you have a 1K trim pot, you might want to try that in place of your 390r resistor on the emitter or Q1 and see if you can dial the voltage from its collector up to that 3v ~ 6V range. You could do the same think with a 10K trimmer in place of the 10K collector. That way, once you box it up and temperature changes, which changes the gain on those GE trannies, you have something you can compensate with. Might as well do a 10K trimmer in place of the 8k2 resistor as well if you're up for it.
I wouldn't mess with the 51K/51K voltage divider. I think that's part of the mojo you have going here.
The small cap from Q2e is a nice mod ... gives that real nice top end boost as heard in the clip. Leave it in.
I like to put a small resistor (100r ~ 330r) in series with the input voltage before the first filter cap just to make a proper low pass filter.
I honestly don't know if the polarity protection diode offers any resistance to do this function or not.
Keep in mind that series resistor, and the protection diode, do drop your V+ voltage a bit but probably not enough to lose the grand fidelity on a fuzzed out signal :icon_mrgreen:
(entered this as Cozy was typing. So you have some options. :P Lots of cooks in this kitchen)
> what is the "stat-tran"
Google and a good eye are your friends.
American Ultraminiature Component Parts Data 1965-66: Pergamon Electronics (https://books.google.com/books?id=Y5yjBQAAQBAJ&pg=PA478&lpg=PA478&dq=stat-tran&source=bl&ots=MJJYvHFGWC&sig=n-TxWw8KxVFz8DcOJ_4bhqgyuXI&hl=en&sa=X&ved=0ahUKEwjX56Ks96TJAhUCPj4KHR0DDt4Q6AEIPjAJ#v=onepage&q=stat-tran&f=false)
Pulse transformers. Essentially zero use in audio.
Quote from: Cozybuilder on November 22, 2015, 12:46:42 PM
Ben- I'd try getting rid of that voltage divider first...
Quote from: Derringer on November 22, 2015, 12:48:18 PM
I wouldn't mess with the 51K/51K voltage divider...
:P ;D
Okay, when I get a chance, I will try all of the above and see if the voltages come up without changing the sound.
I got a little ducking when I ran my FF into it wide open, but FF as a clean(ish) boost worked fine, added some presence and sustain, easy feedback. Otherwise seems to work properly all on it's own.
Quote from: Cozybuilder on November 22, 2015, 12:46:42 PM
...by just sticking a cap between Q1C and the first 51K, leaving the rest leading to Q2B as is...
If I do this, what is a good cap to use? My original layout did have a .1uF right there (I think) or maybe it was .01uF
Quote from: Derringer on November 22, 2015, 12:48:18 PM
I like to put a small resistor (100r ~ 330r) in series with the input voltage before the first filter cap...
I had a 100r in there too but it I didn't notice it doing anything and then I was concerned about the low voltages so I pulled it. Maybe If I can get the volts up, I can put it back in... or even a 330r
Quote from: Ben Lyman on November 22, 2015, 05:59:23 PM
Quote from: Cozybuilder on November 22, 2015, 12:46:42 PM
...by just sticking a cap between Q1C and the first 51K, leaving the rest leading to Q2B as is...
If I do this, what is a good cap to use? My original layout did have a .1uF right there (I think) or maybe it was .01uF
You're generating harmonics here, not tone-shaping, so you want a rather large cap. Why not another 4u7?
Regarding the resistor in series with the Schottky, I like 47ohms. Try out this calculator with different values of R and 100uF, 47R gets rid of most of the audio frequencies on your power supply line, including 60hz:
http://www.learningaboutelectronics.com/Articles/Low-pass-filter-calculator.php#answer1 (http://www.learningaboutelectronics.com/Articles/Low-pass-filter-calculator.php#answer1)
Don't forget, if you add a coupling cap from Q1C to the 51k resistor, you'll have to flip the other 4.7uF cap back to the way it was.
Quote from: Cozybuilder on November 22, 2015, 07:48:08 PM
Regarding the resistor in series with the Schottky, I like 47ohms. Try out this calculator with different values of R and 100uF, 47R gets rid of most of the audio frequencies on your power supply line, including 60hz
Okay, 47r and 100uF gives me a calculation of about 33.86. Does that seem right? A 26r and 100uF gives me 61.21. Wouldn't that be better? I'm really sorry, I don't understand this stuff but I want to.
Quote from: Keppy on November 22, 2015, 08:34:42 PM
Don't forget, if you add a coupling cap from Q1C to the 51k resistor, you'll have to flip the other 4.7uF cap back to the way it was.
Okay, and if I use an electrolytic like another 4.7uF, since they are sort of in series will they go the same direction? Like, + to -?
Quote from: Ben Lyman on November 22, 2015, 11:33:25 PM
Quote from: Cozybuilder on November 22, 2015, 07:48:08 PM
Regarding the resistor in series with the Schottky, I like 47ohms. Try out this calculator with different values of R and 100uF, 47R gets rid of most of the audio frequencies on your power supply line, including 60hz
Okay, 47r and 100uF gives me a calculation of about 33.86. Does that seem right? A 26r and 100uF gives me 61.21. Wouldn't that be better? I'm really sorry, I don't understand this stuff but I want to.
The filter reduces all frequencies above the cutoff frequency. Lower cutoff frequency numbers are better.
Quote
Quote from: Keppy on November 22, 2015, 08:34:42 PM
Don't forget, if you add a coupling cap from Q1C to the 51k resistor, you'll have to flip the other 4.7uF cap back to the way it was.
Okay, and if I use an electrolytic like another 4.7uF, since they are sort of in series will they go the same direction? Like, + to -?
Both (-) go towards ground (through a resistor or two), both (+) towards the transistors.
Thanks Keppy, when I get a chance I will be doing some serious reworking of this circuit and put together a new schematic for the final result. I've been sick as a dawg last couple days so trying to get to bed early and take it easy. Hopefully I will be ready to head back out to the garage soon, stand by for updates!
Get well soon Ben- I look forward to seeing your final schematic.
I'm back with new voltage readings! It really does seem like the voltage divider does something but I am doing a "late-night-quiet-time-thru-the-Champion600" test, so nothing is final yet.
Instead of a trimmer, I just put a 1k in place of the 490r at Q1e. So far everything still sounds great even if the voltages aren't perfect but here's the new readings:
Q1c 4.27
b 0.46
e 0.33
Q2c 0.78
b 0.12
e 0.00
Q3c 4.47
b 0.78
e 0.61
Unfortunately, a good test thru the tweed half stack might have to wait until the weekend.
Let me know if there is anything obviously wrong with these readings.
Today's volts:
Q1c 3.06
b 0.71
e 0.58
Q2c 0.82
b 0.12
e 0.00
Q3c 5.32
b 0.82
e 0.66
How important is it to get Q1b up to 1v? remember Q1 represents a (sort of) stand alone clean boost pedal.
Is there something else I can tinker with?
Would my previous post (^up there^) be a better thing to go with? The sound isn't changing, still sounds like a full stack being driven with a booster pedal at the input, I really like it.
I just wonder if this voltage thing is so important for some reason that I don't know about.
Again, sorry I don't fully understand this stuff and thanks for all the help!
Here's where I'm at:
(http://i64.tinypic.com/auw53.png)
> get Q1b up to 1v?
Maybe you got that number from a Silicon version.
Your build seems to be using Germanium??
The key thing is to find the Collector "about halfway" from zero to battery voltage, so it can swing both ways.
Here it only has to swing enough to slam Q2, which with Q3 needs only a sub-Volt signal. We want Q1 Collector to be able to swing a Volt either way.
3.0V is fine.
Quote from: PRR on November 28, 2015, 08:40:52 PM
> get Q1b up to 1v?
Your build seems to be using Germanium??
Yes indeed and thanks again PRR, this thing might be ready to go.
I still have to run it through my real amp at a decent volume so
hopefully tomorrow I will get the chance.
Getting closer, all the tweaking caused me to lose some of the sustain so I changed the divider into an almost maxed out pot, sounds great now.
I'm not 100% sure I need the 1M right there but I think I heard it get a little harsher when I took it out.
The 10k definitely needs to be there whether it has one 4.7uF or two 4.7uF's.
:icon_question: Did I get those two caps orientated properly? Both positive leads towards the transistors, right?
I still need to give it a "loud test drive" but I think it is ready to solder.
:icon_question: Any tips for creating a layout? I am going to be using pad-per-hole perfboard for the first time.
I have always used plain perf and joined the leads point to point on the underside.
I am hoping I can get a little more creative with this one and make solder trails.
My biggest hangup has always been designing a usable layout with paper and pencil.
Also, a lot of the programs used by most of you seem to be PC only but I have a MAC :(
(http://i68.tinypic.com/fdwt2p.png)
Solder trails. Use the through hole leads and discarded leads to form the traces.
I use diylc. However there are Mac platform cads. Stripboard cad. Is one I've been playing with as an app for the iPad.(not affiliated) just saying have a hunt around.
Nothing wrong with graph paper layouts. That's how I started with a dod250 variation.
Great fun. Take your time refining and checking.
Take a look at Frequency Central's Rob Holt's work for pointers and inspiration...
http://www.diystompboxes.com/smfforum/index.php?topic=84832.0 (http://www.diystompboxes.com/smfforum/index.php?topic=84832.0)
Quote from: Kipper4 on December 02, 2015, 04:32:57 PM
Nothing wrong with graph paper layouts.
I do all of mine on paper now. The programs just slow me down. Unless of course I'm designing a PCB
You got any pointers on where to begin?
I tried starting with the +9v and eventually ran into a road block.
I started over again, this time beginning with the input path and the same thing happened.
:icon_question: Should I start somewhere in the middle?
:icon_question: Are there any particular components that should be kept
far apart from each other?
THANKS AGAIN!!!
I sometime start at the input and work my way along to the output and keep the in away from the out. Opposite sides of the board.
Rather than litterally copying the componants in their orientation in the schematic try putting them all vertical. so they snake around.
leave the power supply till last.
set out your power rails. sometimes you will need to make the ground go round 3 sides of the pcb.
This made sense in my head when i wrote it. i hope it comes across right.
Perfect sense Kipper, thanks!
I think this is close, actually I hope it's dead on. Can anyone tell me which lugs of the tone pot go where so I don't end up with backwards turning knobs?
The green port is input, red is +9v and ground can go somewhere right there too I guess, blue is LED light.
On top under F&G are two brown ports for the tone pot, under R&T are two yellows for the fuzz pot. I can figure out the fuzz pot but I don't know which part of the tone ports is bass or treble.
And, as always, point out any boo-boo's or no-no's.
Thanks!
(http://i65.tinypic.com/2rc0so3.png)
Just had a quick check look all ok to me Ben
Thanks Kipper! I tried to bend your idea into a horse shoe. I hope it works
Horse shoe yep that's kinda what I was trying to say in the email.
Looks fine you could save even more space by squishing the resistors side by side where needed.
Put the power supply caps up above the input.
Turn the d2,d3 around. You could probably save a further 4 or 5 holes in pcb size.
It's just a matter of tweeking.
If your using SIP pins for the transistors that will save some space too. Not that I'm a miniature pcb freak but, it will save money and you have extra left over board for another build.
Have fine refining.
Okay, I tried to scrunch it together but I'm no good at this and very slow t'boot!
Anyway, I think this will work:
(http://i65.tinypic.com/oshkza.png)
and the scheme for easy reference:
(http://i68.tinypic.com/fdwt2p.png)
Quote from: Ben Lyman on December 04, 2015, 12:22:07 PM
Okay, I tried to scrunch it together but I'm no good at this and very slow t'boot!
Ben--
Good Job that you have learned to use DIYLC for perf builds! This new skill will pay major dividends! I think you will find that once you make a build to work on perf, re-drawing in a CAD program that can generate gerber files is easy. Then (if you want) getting a board made is simple and cheap.
An endorsement from smallbear. Cool.
He has a point about the cad.
Thanks Steve. I owe 99% of the credit to Kipper for this, I was spinning my wheels until he showed me how to do it. Thanks again everybody, I'll keep y'all posted!
I would suggest 2 small changes (this won't change your layout)
1- Swap the order of the 47R and the Schottky Diode (just swap these components on the layout) Why? The 47R forms the lowpass with the 2 caps.
2- Take the power for the LED at the 9V input (just connect row A columns B and C, remove the connection to Row J column D). Why? Less current through the 47R, thus less V drop. The LED has reverse polarity protection by design.
Okay, got it Russ, will do, thanks! I was wondering earlier if that 47r/diode order made a difference. Also, I was going to put a 47k from my super brite LED to ground... is it all the same to have that resistor come from that +9v terminal and go to the LED? I think I could fit it on the board right there.
Yes, that will work fine.