This is the TrebleDrive, a vintage sounding Dual Treble-Booster that offers two discrete circuit topologies & sound 'characters' selectable through the Red toggle switch. You can select either the left (April) or the right (May) side.
Each side has a dedicated 3-position toggle switch which give you the ability to select the input capacitor for each side. For each of those 2 toggle switches the middle position is the "normal" state meaning that it represents a typical sounding treble booster. The other two positions offer two different levels of added low end.
- Right side (MAY): A treble-booster circuit built around the BC237 transistor. This side offers you a classic Brian May sound.
- Left Side (APRIL) A treble-booster circuit (with a little more gain compared to the MAY side) built around the BC108 transistor & having as starting point the classic RangeMaster.
▹ True Bypass