Things to do before giving up on a pedal

Started by ethrbunny, May 20, 2005, 01:00:06 AM

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ethrbunny

I have been battling with the 'Dirty sam' looper for several months now. Its seems that I am the only one who can't get a decent sound out of it.

The problem: a periodic background hum that overpowers the recorded sound.

I have tried:
- (the obvious) rechecking the value and orientation of all caps and resistors.
- audio probing (shows a clean signal going into the ISD and a 'noisy' one emerging)
- replacing the ISD2560
- extensive communication with Winbond about debugging tips - they said I wasn't decoupling the chip properly and the sound is a charge pump inside of it. I added / changed caps all around the chip to best reach the decoupling that they specify. No change.
- I bought an oscilloscope in hopes of finding spurious AC in the power lines. Nothing. Nice clean 5V DC.

I have thrown alot of time and money at this build and it has beaten me. I am disgusted as I was really excited to get this one working. Its different and should have been v cool.
--- Dharma Desired
"Life on the steep part of the learning curve"

marrstians

that pedal killed me... i couldn't get it to work right at all... it would record but then it would kill the bypass signal... i gave up on the junk... i haven't built a pedal since... damn...

MartyMart

I know the feeling !!
If you've used good parts, audio probed, de-bugged maybe built a
second version with tripple-checked schemo etc etc........ ?
I have two non-working "tube sound fuzz" builds, which have now had
all the parts removed/re-used ( apart from the 4049's ! )
I can;t get a 4049 build to work..... :roll:

Sometimes it just isn;t meant to be and also wastes too much time, and
that can be precious !!

Marty.

PS: EVERYTHING else that I've built the last year or so has worked, first
time in 90% of them !!
Thats about 30 builds .....
"Success is the ability to go from one failure to another with no loss of enthusiasm"
My Website www.martinlister.com

petemoore

MM, you know about the 'UB' for the 4049's suffix means 'unbuffered' and is important to have the ub chip for certain applications
Convention creates following, following creates convention.

ethrbunny

marrstians - did you get a clean playback (when it would playback)? Maybe we could swap pin voltages or other test errata.
--- Dharma Desired
"Life on the steep part of the learning curve"

MartyMart

Quote from: petemooreMM, you know about the 'UB' for the 4049's suffix means 'unbuffered' and is important to have the ub chip for certain applications

Yup, I got hold of UBE versions for that reason !!  :cry:

MM
"Success is the ability to go from one failure to another with no loss of enthusiasm"
My Website www.martinlister.com

marrstians

yeah, it played back fine but the signal going in sounded like s... i'd have to try and find it in the pedal graveyard... i just dont know if i can risk another heart break... :(

ethrbunny

Well being that we have the (possible) solutions to each others issues.. let me know if you want to give it a try. I'd be happy to copy down voltages and such across the whole thing if it would help.
--- Dharma Desired
"Life on the steep part of the learning curve"

syzygy

One thing you may consider doing is checking all your soldering joints by testing the connections with the multimeter.  I recently built a BSIAB II and it just didn't quite sound as gritty as some of the clips I've heard.  So after double checking the components, I touched the iron to each soldering joint to remelt, and make sure the pads were all well covered with solder.  That did the trick!  The pedal sounds like a beaute now..  I must have gone too fast with my initial soldering and I noticed I left some pads partially uncovered with solder.

Marty Mart,

I built a 4049 Double D but I'm not happy with the sound.  It sounds fairly close to the clips I heard at RunOffGroove, but after remelting the soldering joints on this one, it just sounded the same :?  I've read somewhere besides using UBE that the reliability or consistency of the 4049's are in question.  Aron said this is why he discontinued development of the Insanity Box.  That's why for my next build of the Insanity I ordered a few 4049's to compare them with each other.

aron

QuoteAron said this is why he discontinued development of the Insanity Box. That's why for my next build of the Insanity I ordered a few 4049's to compare them with each other.

Some would gate, others would not. Maddening!

syzygy

Quote from: aronSome would gate, others would not. Maddening!

hey Aron!  How can you tell if the chip gates or not?