Bass mods with TONE pot for GGG's DOD250 build

[rratajski]

http://www.generalguitargadgets.com/pdf/ggg_dist_250_lo.pdf
For bass, I know that it's a good idea to increase the input/output caps (c2 and c7).
I want to add a tone pot to JD/GGG's DOD250 build. I have to ideas for the tone stack below, but I need some handholding here. I don't know how to make this come to life. I would like to see some kind of diagram to show me where and how to wire this. I can perfboard it from leads off of the main board, but where/how do I do that? How am I going to wire up the tone pot (100K linear?)?

Thanks for your assistance in advance.


Option 1

Option 2

[Mark Hammer]

The effects of the input and output caps is negligible.  C2 is the one you want.  The way the unit works, as gain is increased , C2 progressively rolls off more low end, until at max gain the rolloff starts around 720hz.  Not exactly bass friendly.

So, step 1, replace the .047 cap with a .47uf or 1uf unit.  If the latter, the negative end of the cap goes to ground.  That will have several consequences:
1) You will not experience any discernible bass rolloff as you increase gain.
2) You will notice more distortion than before because the brunt of the signal "lives" at the low end, soit starts to sound like you have somehow added more gain

As for tone control, the simplest thing to add, with the least passive bleed is going to be a 10k pot wired up like the SWTC ( http://hammer.ampage.org/files/SWTC.gif ), with a 1k resistor in series and a .1uf cap to ground.  That will provide a treble rolloff with starting points ranging from about 1.6khz down to 140hz.  Given that the rolloff is shallow, you will still be able to hear enough snarl.  In fact, I might even suggest increasing C7 from .001uf to .0068 or even .01uf to roll off more unneeded treble.

You can also consider one of the tone circuits Jack Orman has here: http://www.muzique.com/lab/swtc.htm