Boss DS-1 with Keeley mods?

[SPAZ]

                                    http://www.diystompboxes.com/DIYFiles/up/Build_Your_Own_DS-1_Distortion.pdf

[Mark Abbott]

Thanks for all that information. It is very helpful.

The Jack Orman mod and Brian's mod are quite different. Jack's mod decreases gain, while Brian's increases the gain. I will try both and see what works, I'm staying open minded about it all at the moment.

I do have great chunks of the Keeley mod in my DS-1 so who knows what sort of results I will get?

Thanks again everyone.

Yours Sincerely

Mark Abbott

[WGTP]

I could be mistaken, but Brian's mod should also reduce gain.  Lowering the 470K resistor to 220K allows more feeback to the input reducing the gain.  The larger cap (.022uf) does the same for the highs rolling off around 330Hz, which is pretty low.   

[Mark Abbott]

Dear WGTP

Lowering the value of the 470K resistor will increase the negative feedback to that stage. However, the 470K resistor performs two tasks, as duly noted it provides negative feedback for this stage, but the 470K with the 100K as provides bias for this stage. Thus if the 470K resistor is decreased to 220K there is more base current thus more gain.

Anyway, that is my take on the situation. I believe the increase in gain will be greater than ther effects of increased negative feedback. 

Yours Sincerely

Mark Abbott

[WGTP]

Thanks Mark, I'm sure you know more about it than I do.  That is why I prefaced it.  This stage is similar to the BMP stages.  I was suprised to see it at first.  I'm guessing the transistor used would effect the gain also???   

[Goran]

Hello everyone!
I have a question regarding Keeley mod.....im a total noob in this so im not sure if i should put polarized or non polarized capacitors on positions C2,C8,C9,C14 since original caps are polarized(if im not mistaken:)
Common logic should tel me polarized!

Thank You for Your reply in advance!!

Goran

[Earthscum]

I modded my DS-1 for Bass, but it sounds awesome thick with guitfiddle...

I did the "Fat Mod" from Orman (obviously I was pleased with it, if you read the comments). The other thing I did that really cleaned it up was to mod the diodes. I switch between Si-Si with no added cap, and Ge-LED with a .047u or .47u (can't remember without cracking it open) cap across them. The only time I use the Si-Si is when we play Beastie Boys' 'Gratitude'... then I just crank the dist all the way up and kick on my old KMD Phaser and let the phaser drive the DS-1.

The other mods I did were a couple cap changes. Particularly the cap right before the first gain stage (where you do the Fat Mod). If you are lacking meat, try changing that one out to a higher value. Mine is sitting with a 1u right now. I think I actually ended up changing most of the coupling caps, except for the buffer stages. I don't have a TRUE distortion anymore, I don't think... more like a super-wicked OD.

What it did: I play Ibanez GS205 through a Peavey TNT with BW's. I have the model that has shelving controls to EQ to crossover. When I hit the DS-1, it sounds incredibly like a tube amp being driven by a good quality OD.

I dig it... but remember, I play Bass.

[Renegadrian]

I like Keeley...

[Mark Abbott]

I can't afford that kind of Keeley. 

Yours Sincerely

Mark Abbott

[rousejeremy]

I wonder how many guitarists there are out there that "accidentally" discovered her while searching for pedal mods?