Alternative stack boost...

[wjdunham]

Nothing terribly new here, but a small variation on the theme that I thought I'd share. Since I never use the rock/jazz switch on my #124 (always leave it in rock mode), I implemented a slightly different version of what others here may call "raw" boost. The goal was to find a boost setting that was somewhere in between full PAB and no boost, but that wouldn't have that boxy mid that the PAB can have.
After using a couple of 500K pots to find the right values, I re-wired the DPDT switch to lift the mid pot with a 100K and bass with a 220K. Typically a single 470K is used to lift both, I found this too close to the full PAB for my taste. This mod works really well with a strat, really fattens up the OD, and will give the clean a nice edge without getting honky.
Bill

[JayB]

Nothing terribly new here, but a small variation on the theme that I thought I'd share. Since I never use the rock/jazz switch on my #124 (always leave it in rock mode), I implemented a slightly different version of what others here may call "raw" boost. The goal was to find a boost setting that was somewhere in between full PAB and no boost, but that wouldn't have that boxy mid that the PAB can have.
After using a couple of 500K pots to find the right values, I re-wired the DPDT switch to lift the mid pot with a 100K and bass with a 220K. Typically a single 470K is used to lift both, I found this too close to the full PAB for my taste. This mod works really well with a strat, really fattens up the OD, and will give the clean a nice edge without getting honky.
Bill

You can even tailor the frequencies by adding a cap in parallel to those resistors.

[Structo]

I'd like to try that.
What I am not following is when you say that:

I re-wired the DPDT switch to lift the mid pot with a 100K and bass with a 220K. Typically a single 470K is used to lift both

I see a 100K and 22M and the two .01uF caps (or a .005uF) on the typical Rock/Jazz switch layout.

So with your mod you are switching in a 100K on the mid and 220K on the bass pots?
So these are in place from the pots to ground when switched to this new boost?

[wjdunham]

Yes Tom, I completely remove the components from the rock/jazz circuit and hard wire it in rock mode, al-la the DLite. Then use 1/2 of the DPDT to switch the bottom of the mid pot between ground (normal) and 100K (boost) and the other half to switch the bottom of the bass pot between the normal 10K and a 220K (boost).
I like the idea of playing with different caps across the resistors as well, I need to buy some cap substitution boxes...

Bill

[Structo]

Cool, thanks.
I may have to give that a try.
I'll prototype it on my D'lite and if I like it enough it will go into the 100w.