Boss DS-1 parts layout

[kojjum]

I just bought a used DS-1 that I would like to perform the mods described at FuzzCentral. The problem is just that my PCB is not quite the same as the one described there. I have another OP-amp 7136P and a couple of more ceramic caps and other values on some resistors. I located most of the parts but not all. Does anybody have a schematic with partslayout for this PCB?

Thanks in advance!
//jens

[MartyMart]

Here's a newer DS-1 board, should get you through ! :wink:

http://www.pbase.com/martymart/image/36532354

cheers,
Marty.

[kojjum]

Thanks...almost everything is clear now. One resistor value is still a mystery. My R39 is has a different value than the newer one. Mine is 27k. In the FuzzCentral recepie it says 47k. Do I dare to replace that with 20k or should it be even smaller?

//jens

[RedHouse]

kojjum,

Can you flip that board over and take another pic of the foil-trace side for me? same size as this one if you would please?.

[petemoore]

R39 looks to be right between actives in the signal path.
 This means it is attenuating. Larger Value here will let more into that OA input to the right of it.
 If it were mine I'd:
 Leave it alone.
 B...change it to 47k-56k, leave lead length above the board on that resistor, then clip parallel 100k pot, wired as V/R across it, adjust down in R value to taste, measure the deconnected pots setting [where I liked it, not where it got bumped to], replace with fixed resistor, of closest value that pops up.
 Then I'd probably decide it was just fine where it was to begin with, but never pull the other end off the board to see what I decided on with the pot trick.

[MartyMart]

Kojjum, here's what I know works in my DS-1 mods.
R39  you can go to 20k without problems
R11 change to 51k and R13 to 2k4, this lets the gain "clean up" a bit
R2 change to 620k, bit more input level
R14 change to 1k5 for more top range gain

Cheers,
Marty.

[kojjum]

I'll post it tomorrow...have a professional quality image in my officecomputer.

//jens

kojjum,

Can you flip that board over and take another pic of the foil-trace side for me? same size as this one if you would please?.

[kojjum]

Thanks Marty!

The R11 is not among the changes suggested by Phillip at FuzzCentral. You suggest changing R11 from 70k to 51k. I'll try that!


//jens

Kojjum, here's what I know works in my DS-1 mods.
R39  you can go to 20k without problems
R11 change to 51k and R13 to 2k4, this lets the gain "clean up" a bit
R2 change to 620k, bit more input level
R14 change to 1k5 for more top range gain

Cheers,
Marty.

[kojjum]

RedHouse...here you go!


//jens

kojjum,

Can you flip that board over and take another pic of the foil-trace side for me? same size as this one if you would please?.

[RedHouse]

Thanks kojjum,

I got one for free that had been "bastardized" (traces removed and extra parts soldered on the bottom) and I wanted to see how it is "supposed" to be.

[kojjum]

Here's a PhotoShop manipulated image that perhaps maks it easier to trace.

//jens

Thanks kojjum,

I got one for free that had been "bastardized" (traces removed and extra parts soldered on the bottom) and I wanted to see how it is "supposed" to be.

[MartyMart]

Hey Kojjum, thats very clever !!  could use some more FX looked at in that way  !! :wink:

Hurray for Photoshop !
Marty.