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Digitech PDS 20/20 help, I have a problem.

Started by EliogabaluS, January 08, 2006, 09:13:01 PM

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EliogabaluS

January 08, 2006, 09:13:01 PM Last Edit: May 18, 2006, 07:01:56 AM by EliogabaluS
Hello guys

does anybody have that schematic?

i connect the delay and sound like this:
http://rapidshare.de/files/10753978/MOV06382.mp2.html

what can be?



Best regards
:icon_wink:

Khas Evets

#1
January 09, 2006, 02:52:01 PM
I have one of those pedals as well. I don't have a schematic, but I've been thinking about an op amp upgrade. The op amps are TL062's and I was going to try OPA2604's or maybe TL072's.

niftydog

#2
January 10, 2006, 08:31:14 PM
have you eliminated all the variables? Tried a new battery or a power supply? etc etc.

This could be a very difficult fix if it's not just a flat battery or something. I've never encountered schematics of this range.
niftydog
Shrimp down the pants!!!
“It also sounded something like the movement of furniture, which He
hadn't even created yet, and He was not so pleased.” God (aka Tony Levin)

EliogabaluS

#3
January 11, 2006, 12:39:34 PM
Quote from: niftydog on January 10, 2006, 08:31:14 PM
have you eliminated all the variables? Tried a new battery or a power supply? etc etc.

This could be a very difficult fix if it's not just a flat battery or something. I've never encountered schematics of this range.

yes.

dr

#4
January 11, 2006, 02:40:55 PM
.....sounds like my 20/20 did when the repeat button got smashed and shorted on...I also had a small solder blob inside the regen pot (it had been replaced when I got it)....I'd check the repeat switch first..... 

toneless

#5
January 11, 2006, 05:24:21 PM
Quote from: dr on January 11, 2006, 02:40:55 PM
...I also had a small solder blob inside the regen pot (it had been replaced when I got it)....

I'll second that! You can't check many things in a digital delay anyway. Check any internal trimpots, too.

EliogabaluS

#6
May 17, 2006, 04:09:39 PM Last Edit: May 17, 2006, 04:14:01 PM by EliogabaluS

StephenGiles

#7
May 17, 2006, 04:13:27 PM
I can't download that schematic from Rapidshare, clues anyone?
"I want my meat burned, like St Joan. Bring me pickles and vicious mustards to pierce the tongue like Cardigan's Lancers.".

EliogabaluS

#9
September 30, 2006, 11:53:39 PM
what can i do???  :icon_cry: :icon_cry: :icon_cry:

i change the op-amps TL072 (when i change this op-amps, the effect is always activated, i can't change to bypass) , change the 330uf electrolitic, the 78L05, the 1N4001, all pots and it follows with this sound: http://rapidshare.de/files/35055197/VOC001.WAV.html

moldava

#10
October 01, 2006, 09:34:28 AM
could you please reupload to RS?

dr

#12
October 01, 2006, 02:48:59 PM
....have you checked the two switches yet? one may not be making contact, or one may be smashed in and would be shorted on all the time, and it is keeping it from toggling the flip-flop......

EliogabaluS

#13
October 01, 2006, 03:50:26 PM
Quote from: dr on October 01, 2006, 02:48:59 PM
....have you checked the two switches yet? one may not be making contact, or one may be smashed in and would be shorted on all the time, and it is keeping it from toggling the flip-flop......

yes  :icon_confused:

moldava

#14
October 01, 2006, 05:39:16 PM
Quote from: EliogabaluS on October 01, 2006, 11:41:53 AM
Quote from: moldava on October 01, 2006, 09:34:28 AM
could you please reupload to RS?

reupload what?

Sorry,the pdf schematic to rapidshare...

BTW,do you have acces to an oscilloscope? the best way to troubleshoot this is ton inject a sine wave and test it after the different stages
(pre filter,compressor,a/D input,that guides you around biasing problems,d/a,expander,post filter,etc)

those stages should be in another page of the schematics set...

EliogabaluS

#15
October 01, 2006, 07:41:20 PM
here is:  http://img422.imageshack.us/my.php?image=pds20207rz.jpg

but, i don't have the page 1   :icon_confused: (digitech send me only page 2)

EliogabaluS

#16
August 20, 2008, 03:06:41 PM
hi everybody!

after a long time, im trying (again) to repair this delay.

I found a trouble at the power supply, only give me 3,74V when is a 9v power supply.

what can be?

i think maybe is the jfet j111

here is the schematic:



regards
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