Ruby ‘63 controls are identical to the British top boost amplifier that it is modeled after. This means that some EQ knobs on the amp will function counterclockwise when boosting or cutting certain frequencies.
The controls work as follows:
Cut
Reduces high frequencies by filtering the power amp. As you rotate this knob clockwise, the amp tone becomes darker.
Bass / Room
Adjusts two different settings, depending on the position of the Alt / Amp / Store switch.
- AMP mode: Reduces the low frequency response of the amp’s tone stack on the Brilliant channel only.
- ALT mode: Adjusts the amount of room tone mixed into the signal.
Treble / Speed
Adjusts two different settings, depending on the position of the Alt / Amp / Store switch.
- AMP mode: Reduces the high frequency response of the amp’s tone stack on the Brilliant channel only.
- ALT mode: Adjusts the amp’s vibrato speed.
Note: The Bass and Treble knobs cut bass and treble frequencies as you rotate them clockwise (in effect, they work in reverse of most EQ knobs).
For more in depth information on the control layout of Ruby ‘63, please see the manual here.