Just came into 3 busted DOD 680 analog delays....

[BraindeadAudio]

Need to repair em, I have one with an SAD4096, and 2 with the Reticon chips. Anyone ever work on one of these?   They seem pretty rad with the transformer and everything.

Also got about 6 Digitech Echo plus units all with different problems.

Guess Ill make this thread my troubleshooting in case anyone ever needs help fixing one.

Chat away!

[madbean]

Are these the ones that were on eBay a month or two ago?

[BraindeadAudio]

Nah I got them as a comissioned repair along with the others out in austin.

[BraindeadAudio]

Ok, one of the units, the earliest one, has a bad power switch and the Normal/P.A. switch is missing. Board was crudely repaired by someone with what looks like a soldering gun and scorched the solder traces, will have to place jumper wire. 120Pf capacitor placement completely gone, Soldered between the 2 points as shown on schematic.

http://3.bp.blogspot.com/-jao2BMt3h6E/TrBE-MlkyiI/AAAAAAAAACw/O0yl3LAF77w/s1600/dod680.gif


Updates and gutshots coming once I replace the power switch and Normal/P.A. switch.

[BraindeadAudio]

Gut shot after wiring it back up


Was making odd noise, traced it to a bad cap and replaced it and turned it on,


And we have a working unit!

Only thing is the AC wall plug has to be rigged to the power switch so I gotta get a correct power plug, but it sounds amazing.


I have to trouble shoot the other 2 units now because I had to salvage parts from those 2 to make this one a working unit, but at least now I have a base working model to repair them from.

Brian, this would be an awsome unit to make a board for! 
Im sure most of the mojo of this unit is the unobtainable chips though.
If anyone sees one of these grab one! Theyre awsome

[bigmufffuzzwizz]

Great pedal. I was recommended one by a buddy and it really gets the job done well. I loved the unique spaceship sounds attainable from this pedal. Mine has a different silkscreen than yours pictured though. Do you notice a bleed through of delay when bypassed? Someday I'll have to switch it to a 3pdt...

[BraindeadAudio]

I have one with the other silkscreen, it also doesnt have the Normal/P.A. switch. I dont notice a bleed on the one I fixed.

According to a few sources these Reticon BBD chips are worth a pretty penny.

[bigmufffuzzwizz]

Thats probably the one I have, which doesn't have the normal/p.a. switch. What does that do?

[BraindeadAudio]

It seems to boost the signal a bit, i Am still figuring the unit out completely. It gets really buzzy and loud when that is engaged though hence why I think its a boost.

[lincolnic]

Is it possible that it switches the pedal to line level for use in a PA system, rather than instrument level for a guitar?

[BraindeadAudio]

that is entirely possible. That may make it work for a keyboard.

[reedha]

hey i have a 680 delay and it makes extreme white noise when turned on...any idea why and is it fixable? thanks

[jwin615]

hey i have a 680 delay and it makes extreme white noise when turned on...any idea why and is it fixable? thanks

Start with any electrolytic caps.
I'm not familiar with the pedal but sounds like it's AC input, so should have a some power stuff going on. Start there.

[lars]

Anyone ever work on one of these?

Yeah, I've done a little bit of work on one:
https://www.madbeanpedals.com/forum/index.php?topic=15117.msg142049#msg142049