in MODE 1 the gain controls operate like a "jumped plexi"
in MODE 2 gain A is a traditional gain like that of a JCM-style amp, and gain B allows you to modulate the gain in the middle of the preamp
K1 and K2 are boosts on the first and second gain stages respectively, you can boost mids and highs or boost all frequencies with a robust low-end. These are hugely influential on the gain structure of the amp.
Bass - Mid - Treble: Standard controls with an unexpected large range, don't be afraid to turn these knobs...
Shift- Allows for a boost in the Hi-Mids and/or Lo-Mids
Pre-Vol- A volume control after your preamp, this is the standard "master volume" on most amps
Depth- an NFB dependent low-end boost
Presence- an NFB dependent treble boost
NFB- Our favorite control on this amp, this controls the Negative Feedback, a key component to how any amp sounds and feels. Large amounts of NFB will tighten up the amp while rolling off the high-end sizzle, whereas small amounts will let the preamp through in all its harmonic glory, at the expense of possibly getting a little wooly and or harsh. Once you have this control, you'll wish all your amps had it...
POST MV- This master volume control happens after the preamp, effects loop, and phase inverter, controlling your signal right before it hits your power tubes. This allows you to push your phase inverter hard, getting a lot of growl that used to be associated with the power tubes, without the volume usually comes with it.
