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Old 10-19-2004, 10:53 PM   #1

Join Date: Dec 2000
Posts: 986
Hi-Pass Filter trick

I had a revelation today. It's so simple yet so usable. I don't like the HPF's because, although they're cool for using your volume knob like a gain knob, or a clean/crunch adjustment, I often play clean jazzy solo stuff with the tone control down. The problem I have is when you've got the tone knob down, and you're working the volume knob, you get a crappy sound because at the tone knob you're cutting the highs, while on the volume side you're letting the highs pass through while reducing the lows. You're sucking "tone" from both ends. If you have a neck single coil it's even worse. Here's my solution:

Instead of having the Hi-Pass cap jumping across the switch hot lug and the volume output lug, I run it through the tone pot. First, the wire that leads to the tone knob has to be coming from the switch hot (1st lug) not the output (center lug) and the tone knob has to be wired in the stock "modern factory guitar" fashion, with the wire from the pot going to the center lug of the tone pot, and the capacitor going from the right lug to ground. This leaves the left lug of the tone pot open. We will use that left lug. The little capacitor that jumps the two lugs on the volume pot needs to be removed from the switch hot lug only leave it connected to the center lug. Finally jump a wire from that open lug on the tone pot to the newly disconnected capacitor wire.

*Here's what it does:
When you have the tone knob all the way up, there's no change. The pickup hot is feeding 100% through the Hi-Pass cap to the center lug, and everything is as it was. But as you turn the tone pot down, the Hi-Pass cap becomes less and less "connected" to the pickup hot (due to the tone pot's resistance increasing) and therefore allows less and less "Hi-Pass" filtering to occur. Eventually, when the tone knob is all the way down, the Hi-Pass is disengaged. I did it today on a RG550 and it's awesome. It now makes the tone knob totally usable even when you're also playing with the volume knob! If anyone can tell me that there's a problem with this, I'm glad to listen, but I don't think there is. If it's been invented before, I appologize! Theoretically, I imagine that a 500k tone pot is ideal, since you want as little coloration as possible when the tone pot is at "10" but I don't think it really matters.

ashbass interpretation of Frank's idea
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