DIYstompboxes.com

DIY Stompboxes => Building your own stompbox => Topic started by: gorohon on December 01, 2003, 01:24:05 AM

Title: Need: A definitive solution to zombie and Ultra Flanger
Post by: gorohon on December 01, 2003, 01:24:05 AM
I've already asked about the Ultra Flanger, but here I go again.  While I've managed to get rid of the unwanted distortion ( by cranking tr3 all the way up),  the ticking is still present.  If I run my boutique fuzz69 first (with a low bias on the fuzz) it does tend to gate the ticking.  When this setup is employed, I can really hear how nice this effect can be.  To be honest, it got me excited (not in a sexual way).   I then went back to clean and the tick was there.  

I've noticed that with both the Ultra Flanger and the Zombie the tick and swoosh are only noticable when I'm not playing.  On my Zombie, I've tried the  de-tick mod, but I had no success.  I had ticking and an uneven sweep.  This might be because of the cheap resistors I've used (some have been way off advertised value--from All Electronics 500 pack ass.).  So I tried the Kluge add on, as mentioned by Mark Hammer, I believe.  This fix helped out the uneven sweep but not the tick.  I don't even know if I did it right (do you cut the trace from the opamp or not --I didn't cut it).  I'm using njm062 dual opamps for both effects.

I think that I would like to know more about using offboard trimpots to adjust bias on pin 3 of the mn3007/nte1641.  By the way,  people who have heard these effects of mine think they're great, but then add "what the hell is that noise?"
GDK.
Title: Need: A definitive solution to zombie and Ultra Flanger
Post by: bioroids on December 01, 2003, 08:05:34 AM
I have this same problem.

Also noticed a huge amount of hiss on the chorus sound? I changed the values on the filter sections and got rid of that noise.

Good luck

Miguel
Title: which caps exactly?
Post by: gorohon on December 01, 2003, 11:38:44 PM
I would like to know which caps exactly that you are refering to?  What values worked for you?  

I am wondering who, else has tried to use an off-board trimpot to bias the delay I.C. (pin 3) on the zombie?   Anybody else using the NTE 1641?  

Also (anyone), Could you get rid of the Ultra Flanger's diode pair that biases pin #3 for the Delay I.C. and graft in an off-board trimpot to set the bias? :idea:
Title: Need: A definitive solution to zombie and Ultra Flanger
Post by: bioroids on December 02, 2003, 08:24:44 AM
I dont remember the values now, i'll check them at home later. I mean the filter opamp section at the output of the bbd.

I used a MN3207, had to adapt a lot of things, including a bias trimpot on pin 3. Anyway I couldnt make it work on the "clone" mode no matter how i tried.

Regards

Miguel
Title: might have something here
Post by: gorohon on December 17, 2003, 12:43:34 PM
I'm now trying to figure out how to include some expanding using the sa571n chip.  If this works for the Zombie, I'll let you all know about it.  This is big, considering that I'm a beginner.  But, I've got to get this thing quiet, so I'm determined to explore this to reality.  I bet, within a month, that I'll get my Zombie to shut up :!:
Title: Need: A definitive solution to zombie and Ultra Flanger
Post by: Fp-www.Tonepad.com on December 17, 2003, 12:48:00 PM
Not to sound like a wise ass, but I may suggest building one of these:

http://www.tonepad.com/project.asp?id=8
http://www.tonepad.com/project.asp?id=26

They're very quiet.

Fp
Title: no offense taken
Post by: gorohon on December 17, 2003, 11:11:36 PM
Yeah, you're suggestion is well received.  Come to mention it, I have thought  about it previously.  I'm the type of person, however, that just likes a challenge.  I'm also more of a mechanic, I like to build things just to build them, sometimes, and fiddle with them.  I'll go ahead and bust my ass just for the hell of it.  Then I'll probably give my Zombie away to a friend, then build the Tonepad Small Clone project.
I do appreciate people turning me on to new things.
Thanks
:D
P.S. I thought that someone might appreciate this: I'm building a crappy fuzz inside an Altoids tin.  If the fuzz was my own design I'd dub it (wait for it) a Sh#t Face  :!:  It probably won't be a "stomp" box, more of a "gentle nudge with-the-toe box".   I don't care if this is sad or cool.
Title: Need: A definitive solution to zombie and Ultra Flanger
Post by: Joep on December 18, 2003, 03:49:15 AM
Tonepad's Small Clone project is great, it works right out of the box, and it will save you a lot of frustration.

The project is marked as advancend, but it you work tidy and consentrated is shouldn't be a big problem.

Bye,

Joep
Title: Need: A definitive solution to zombie and Ultra Flanger
Post by: bioroids on December 18, 2003, 08:07:55 AM
Hi, I checked the values for the filter section I used (the three resistors and three caps that lead to the opamp after the bbd) I used all the same value 6K8 for the resistors and 0.01uf for the caps. I controled better trhe hiss on my MN3207.

Hope it helps

Miguel
Title: thanks for the "valued" information
Post by: gorohon on December 18, 2003, 12:55:09 PM
Thanks for the information.  I'll try that and see what happens.  After I try all the things that I plan on doing to my Zombie, I think that it will be something completely different from what the original intent was behind the Zombie concept--simplicity.  What I'll have in the end will be more appropriately known as a Frankenstein.  You Tonepad (Small Clone) guys are alright; I think I see the light.  Still, I hear my Zombie (calling Dr. Frankenstein....)

Oh, by the way, did changing those values in the filter section effect the tone?
Title: Need: A definitive solution to zombie and Ultra Flanger
Post by: bioroids on December 18, 2003, 02:10:14 PM
Hi, the filter with the new values cuts off more highs, i dont remember the frequency point. The you have less highs on the delayed part of the chorus signal. This may affect the tone, but I made the changes before testing it right, so I dont know if its bad or good for the tone.

I'm using MN3207, not MN3007 so this may work different for you. I was (am) having problems to adapt this chip to the zombie. Particulary I cant get rid of the ticking, even with Mark Hammer's mod.

Im using TL072 for the LFO, is there a better choice for this application? It's supposed to make a triangle wave, but at least on the simulator is a hard square wave.

Any help apreciated.

Luck

Miguel
Title: Need: A definitive solution to zombie and Ultra Flanger
Post by: Mark Hammer on December 18, 2003, 02:52:14 PM
I suppose I can't speak for John Hollis, but my sense is the Zombie was really meant to be an I-can't-believe-I-can-have-a-working-chorus-this-easily-and-cheaply sort of device.  It attained that goal by cutting a few design corners in a clever way.  The cost to that is that insufficient attention was paid to noise.

The Small Clone, on the other hand, was intended to be a commercial product that would result in few customer complaints, so most of the noise issues were addressed.  The nice thing about the SC is that even though you could still implement them on the Zombie, they are already part of the SC and the layout includes them.

Because of the impact that shifting the delay range has on subjective chorus tone, naturally different users will treat chorus X as sounding nicer than chorus Y to their ears.  In truth, once you attend to the noise, there really isn't a whole lot of difference between chorusses, and most audible differences disappear when you adjust the delay range.

If one likes the delay range of the Zombie but does not like the noise of it, you can play with the values of what is currently a 150pf cap.  Making it larger will shift in the direction of longer delays (usually described as "thicker"), and making it smaller will shift in the direction of shorter ones (usually described as being more like flanging or rotating speaker).
Title: This may seem off the topic, but...
Post by: gorohon on December 30, 2003, 10:39:35 PM
Could half of a tl062 sub for an LF351?  I think I found a suitable expander circuit that is small and might be interesting to see how it would work integrated into the Zombie.  I might fiddle with my off-board trimpot  setup as well.  This will be figured out someday,  I suppose.  You learn more from solving problems than by "painting-by-the-numbers".
Title: Need: A definitive solution to zombie and Ultra Flanger
Post by: Maneco on December 31, 2003, 12:43:02 AM
Hi,
lf351 and tl062 are jfet inputs opamps,so my guess is that it will work...
btw,do you have a link for the small expander circuit?
happy new year !!!!

Maneco
Title: It's not on the net to my knowledge.
Post by: gorohon on December 31, 2003, 01:40:32 PM
I came across a book in a second-hand bookstore called "Electronic Projects for Guitar" by RA Penfold.  It looked interesting, so I got it.  I haven't done any of the projects tough.  One project is an expander.  It uses an LF351N and a NE571 compander.  The book gives you instructions like EPFM's does, the schematic, but it does not have any PCB layouts.  The projects are done on stripboard.  What I have done so far, with the expander idea, is sketched a PCB for it (I made it 5x2.5cm).  I'll see how it works, then I'll see what use it would be integrated with another project.  I figure this way I'll at least have an expander.  I don't know, legally, if I could scan it out of the book and post it somewhere without the author's permission.  What I'll probably do is make this one using my PCB, verify it, then I'll gladly share what I can with y'all.   I think in a month or two I'll have it done (I'm preparing for the GRE right now).
Title: It's not on the net to my knowledge.
Post by: gorohon on December 31, 2003, 01:40:57 PM
I came across a book in a second-hand bookstore called "Electronic Projects for Guitar" by RA Penfold.  It looked interesting, so I got it.  I haven't done any of the projects tough.  One project is an expander.  It uses an LF351N and a NE571 compander.  The book gives you instructions like EPFM's does, the schematic, but it does not have any PCB layouts.  The projects are done on stripboard.  What I have done so far, with the expander idea, is sketched a PCB for it (I made it 5x2.5cm).  I'll see how it works, then I'll see what use it would be integrated with another project.  I figure this way I'll at least have an expander.  I don't know, legally, if I could scan it out of the book and post it somewhere without the author's permission.  What I'll probably do is make this one using my PCB, verify it, then I'll gladly share what I can with y'all.   I think in a month or two I'll have it done (I'm preparing for the GRE right now).
Title: Need: A definitive solution to zombie and Ultra Flanger
Post by: Maneco on January 02, 2004, 08:09:11 AM
HI,
if you go the sa571 way,it's better to build a compander,there are many around ,but one of the easiest design i've seen is the tokai analog delay,found in schematics section,it can be easily added to the zombie or ultra,it works...i think it's your solution,ask if you need some help getting it working

All the best

Maneco
Title: cool!
Post by: gorohon on January 02, 2004, 03:11:05 PM
I'll check that out.  Thanks!
Title: where does it go?
Post by: gorohon on January 11, 2004, 10:12:04 PM
Maneco,
I figured out, for the most part where the compresser goes in, comes out, where the expander comes in, and goes out on this tokai analog delay. But the only pin I'm left scratching my head on is pin 5.  It is hooked up to the regeneration feature of the pedal.  Would this just be left unhooked in a chorus application?  Next question:  Where should the copresser in start, before or after the buffer?  Should the expander start before or after the filter section?  Can you all hear that?  That's the sound of me biting off more than I can chew!
Title: Need: A definitive solution to zombie and Ultra Flanger
Post by: idlefaction on January 11, 2004, 10:43:59 PM
my chorus is ridiculously cheap... it's an LFO driving an LED coupled to an LDR that alters the delay time on a pt2399 delay.

love those acronyms.  :P

it takes up about a square inch of PCB, and cost me in the order of USD$10  :D  :D

i bet you could make something similar hacked onto pretty much any delay pedal.  if the delay goes fast enough, you could even make it a flanger as well!
Title: Need: A definitive solution to zombie and Ultra Flanger
Post by: Maneco on January 11, 2004, 11:12:32 PM
hi,
regarding pin 5,just leave out the pot and 100n/10k series,they are the regeneration path...but you coulkd add it to get some extra effects from the chorus...i also suggest that you  replace the buffer stage of the zombie with the full audio in path of the tokai,the same for the output expander,wire it after the filter stage of the zombie and copy all the rest of the circuit,maybe shortcutting the fet for adding a true bypass a la millenium...

all the best


Maneco

good luck,i know you can do it...
Title: now we're getting somewhere!
Post by: gorohon on January 12, 2004, 02:49:40 PM
Thanks again, Maneco.  I'm going to go ahead and build a completely separate zombie to do all of these ideas.  First order of business, go buy myself a good breadboard.  Second, get started.  I'm going to shoot for a completion in March, as I have some other personal goals to accomplish first.  But whether success or failure, I'll report back.  Idlefaction, your chorus sounds interesting.  You ought to post the details of your customized delay-turn-chorus effect.
Title: Need: A definitive solution to zombie and Ultra Flanger
Post by: gorohon on January 12, 2004, 02:54:57 PM
I just looked at your manecolooper and microlooper.  I'm a big fan of Robert Fripp and his Frippertronics stuff.  I imagine that one could do similar stuff with your effects. Maybe, down the road, I'll buy one of your creations.
Title: Need: A definitive solution to zombie and Ultra Flanger
Post by: Maneco on January 12, 2004, 06:50:32 PM
thanks for your feedback on my machines...
what i ususally don´t use is a breadboard,i try everything on soldered perfboard,but that's my way of doing things...
Title: Need: A definitive solution to zombie and Ultra Flanger
Post by: gorohon on January 13, 2004, 12:50:46 PM
I've never used a bread board before, maybe I should just stick with what I know.  Plus, I could use the money to buy parts instead of the bread board.