August 12th, 2011, 05:42 AM
First post here, great site! Anyhoo, I Love the amp as is pretty much but want a bit more thump. It has become my small weekend rig/ amp. A lot of Jet City JCA 20 players have been adding this control to there amps and was wondering if it can be done with a Rebel 20. Any schems or layouts or options other then the control would really help! VG
August 12th, 2011, 12:31 PM
The Depth mod is what is often called a "Resonance" control. This is part of the Negative Feedback circuit.
It is the opposite of a Presence control. Presence allows treble frequencies to bypass the negative feedback loop, making the amp sound brighter. Resonance does the same thing, except it bypasses bass frequencies from the NFB.
If you can find a schematic for the Rebel 20, it would help.
I'm not sure if the Rebel 20 already has a NFB (fixed resistor since it does not appear to have any Presence knobs).