What Is This Switch Doing?

[psiico]

I have an old Epiphone something or other and it has a DPDT switch that looks like this from behind:

Can someone tell me what it's doing? The wire marked from switch is the hot wire from both pickups after the selector switch. The ground wire seen around the sides of it is soldered to the side of the switch box.

I know what the throws connect on those switchs and that's about all I know. Looking at that confuses the heck out of me, lol. Sorry, I don't know much about electronics.

The effect it has is that when the switch is in the up position I get a full, rich sound, lots of low end and nice highs and when the switch is down I get a much quieter and thinner sound. To be honest I don't even know if up is on or off, lol. Is the cap being engaged then making it sound better or is the cap being engaged and making it sound worse? I want to know because I'm replacing pots on another guitar and while I'm in there I want to install a similar circuit in there if engaging that cap makes it sound all rich and full like that.

Any help would be appreciated.

[psiico]

You know, I stared at this for hours and couldn't figure it out but now it just came to me. When the switch is up the cap is off. When it's down the hot wire signal passes through it to the volume pot. So that means turning it on kills the sound, which means I don't want it on my other guitar. No wonder I didn't see a similar mod on any webpages, it sucks, lol.

I'd still like an explanation of what it does and why it affects the tone that way though. And confirmation that I'm right too please.

[lovekraft]

That looks right - if the cap is in series with the output, it's a simple high-pass filter, sucking the bass out of the signal. Why it's there is anybody's guess.

[JoeAArthur]

That looks right - if the cap is in series with the output, it's a simple high-pass filter, sucking the bass out of the signal. Why it's there is anybody's guess.

Yep, it's a "bass cut" switch. One of those three switches on the lower bout of a Fender Jaguar does the same thing, only they used a .0033 cap.

[psiico]

Okay, so I don't want that. Thanks guys. While I'm in there I think I'll rewire that switch as a phase shifter for the bridge pickup. Might as well use it for something since the hole is there.