"With the incorporation of our "Steel Guitar Black Box" circuit with it's variable impedance ("Vari-Z™") pickup loading tone control, the sweepable midrange (Color) control, the bright/normal/dark switch, the stereo-parallel effects loop, carefully selected audiophile signal and tone capacitors, non-magnetic metal film resistors, boutique carbon film resistors, and carbon comp resistors in ideal locations, humless DC heater supply, and an all-tube signal path, you'll find a tonal flexibility and purity unlike any preamplifier you've heard before."
Actually, the Treble control effects the midrange frequency. The sweet spot is from 3-4. This will put your midrange in the necessary placement for steel 700-800hz. The Color control is more like a blend to soften the mids. I found that the Color control usually ends up at approximately the same dial setting area as the Treble. I found the Rev to be a little more complicated than the solid state steel amps. Once you play with it and understand it, you can zero in on exactly what you're looking for for tone. You can also play around with different tubes. Currently, I'm using the new JJ 12AX7MG (mid gain) preamp tubes.
The Vari-Z and Tone Switch is also a big factor in finding your preferred tone. Another big factor is your pickup. There's a lot involved.
1976 Birdseye U-12 MSA with Telonics 427 pickup, 1975 Birdseye U-12 MSA with Telonics X-12 pickup, Boss 59 Fender pedal for preamp, NDR-5 Atlantic Delay & Reverb, two Quilter 201 amps, 2- 12" Eminence EPS-12C speakers, ShoBud Pedal, 1949 Epiphone D-8. Revelation preamp into a Crown XLS 1002 power amp.
