Rebote 2.5 distortion

[soapamp]

I already search all the tread here about Rebote 2.5 noise, hiss, distortion.   I tried to fix my pedal built.  It has some distortion that came with the delay.  Delay pot at 9 o'clock still has the distortion.  How can I debug it.? 

[Auke Haarsma]

This is a really helpful thread to pin point problems with a build:

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

[soapamp]

Tonepad Rebote 2.5  http://www.tonepad.com/getFile.asp?id=98

It has delay sound and able to control all the pots.

Problem:  Distortion sound at the end of delay, will be more when Level over 3 O'clock.

Parts Changed as below
1) Delay pot change to 100kb
2) Repeat pot change to 100kb
3) Level pot change to 100ka
4) change 1uf to 150n of TL072 pin 7
5) change .1uf to .01uf, 15k to 6.8k at Repeat Pot Lug # 2

Another parts are still same as stock listed.

[Treso]

So does it work ??
I have the same problem. Soapamp  can you write more precise about this mod please ?

thanks

bye

[ppatchmods]

3 things that i have found on this circuit that will cause noise:

1. carbon comp resistors that may be a little old
2. a noisy/bad pt2399
3. a noisy/bad opamp

[Treso]

Resistors are new metal film 0.6W with 1% of tolerance.
Opamp is TL072CP. And i tried to change with new new on, but no effect.
Meaning that I have to buy new PT2399. So bad.
Here is the sound sample.
http://wap.esnips.com/doc/f6993fb0-8702-4d9d-9b7b-c4e4568e4b49/distortion-rebote-2.5
Please listen to the sample.

[soapamp]

Thank you for all advised. I already build 3 units and all of them are difference in small details.  PT2399 is the main problem

[deadastronaut]

ive built the rebote.and echobase....i think if i remember correctly , the pt2399 delays

will always get dirty on the trails/decays anyway..mine do..

i may be wrong...but mine dirt up a bit on long delays for sure...

i put a big pot on it to double the delay length and it got nasty , so changed it back...

thats my 2p/cents .

[gtudoran]

That distorsion/hiss is normal for PT2399 there is no solution for it.

Best regards,
Gabriel Tudoran
Analog Sound

[cpm]

That distorsion/hiss is normal for PT2399 there is no solution for it.

well there is (to some extent), but not in such a simple circuit like this one.

[ppatchmods]

i have built many of these circuits and i can say with confidents that some pt2399's are quieter than others. some have dirt on repeats as early as about 250ms and some not until about 450-500ms. in my experience (some have more i know) it is a combo of the resistors, opamp & pt2399. i read somewhere that shipping scanners could have some affect but that is hear say and could be a good myth for the busters... 

[cpm]

i have built many of these circuits and i can say with confidents that some pt2399's are quieter than others. some have dirt on repeats as early as about 250ms and some not until about 450-500ms. in my experience (some have more i know) it is a combo of the resistors, opamp & pt2399. i read somewhere that shipping scanners could have some affect but that is hear say and could be a good myth for the busters... 

i believe that an actual cause of that variation may be, as you said, the components around the chip. How fine-tuned is the low pass for cleaning noise, the gain applied throug the delay ic, the band pass for the feedback... even in one same design, some caps have huge tolerances that can alter the filter points, etc...

by the way, i cant believe that 500ms noise-less PT  (¿in a rebote like circuit?)