boss ds-1 repair

phil_b

I just bought this on ebay as a faulty pedal. The description says the distortion knob is stuck in one position and can not be adjusted.

I am hoping a new pot will fix it. As I wait for it to arrive can anyone tell me what type of pot I need. If I can order one whilst waiting for the pedal it would speed things up a lot.

ICBM

The pot is 100K linear, but if I remember correctly there are different versions used depending on which series the pedal is - the early knobs have a set screw (needing a solid-shaft pot) and later ones need a split/splined pot.

I would hold off until you have the pedal, anyway - it’s not unlikely you can free it with a bit of care and some WD-40, in which case you don’t need a new pot...

phil_b

thanks for the advice. Patience is not my strong point but you are right it will be better to wait

SteveRobinson

phil_b said:

I just bought this on ebay as a faulty pedal. The description says the distortion knob is stuck in one position and can not be adjusted.

Well you couldn't turn that down [Badum tish!]

randella

Fiver says you fix the pot and end up setting it exactly where the old one was

ICBM

randella said:

Fiver says you fix the pot and end up setting it exactly where the old one was

lol... wis

phil_b

well the pedal arrived.

the pots seem to turn fine so I plugged it in and the level and tone pots function correctly. the pedal has zero distortion and turning the dist pot has no affect. I opened it up and the pot measured out ok and the connection are fine.

then checking the board for any obvious damage I noticed capacitor C8 was missing. it has been snapped of and only the legs are left soldered to the board. the body of the capacitor was not in the pedal so this shows the pedal has been opened up before. This may be the fault or it could be damage after someone was poking around in there.

a quick google shows C* should be a 0.47uF cap and is part of the distortion control circuit so there is still some hope there that this could be the only fault.

 

ICBM

Yes, if C8 is missing that will turn it into a clean boost (if there is even any boost, it will give the second IC stage very close to unity gain) pedal... sounds like someone has been fiddling without knowing what they were doing.

randella

There goes my theory then

At least the cap will only cost you pennies to find out.  I wonder what they were up to?

LastMantra

Good buy! Assuming it was cheap of course. 

phil_b

LastMantra said:

Good buy! Assuming it was cheap of course. 

not really. I over paid to be honest but I do like tinkering with stuff

phil_b

well after having to wait a while for the correct value capacitor to arrive I soldered on into the gap on the board.

and I got luck and the pedal now seem to be working fine. happy with that

phil_b

It still a mystery to me how a circuit board can loose a capacitor however