11
TUBE LAYOUT & FUNCTION
V1 - V4
Class A/B power output tubes: EL34, 6CA7, KT77, 6L6, 5881, KT66,
6550, KT88, KT90, KT100
V5
Phase Inverter: 12AX7
V6*
FX Loop: 12AT7 only.
V7
4
th
gain stage & Cathode follower: 12AX7
V8
2
nd
and 3
rd
gain stage: 12AX7
V9
1
st
gain stage: 12AX7
* Optional
TIPS & SIDE NOTES
If you want a half power function without the removal of tubes, simply pull out either the
T.5A V1&V4 or T.5A V2&V3 fuse located with the bias controls. The transformers
were designed to take serious abuse. No need to do math to figure out the correct
impedance when doing so. Experiment with different impedances and go with what
sounds best to you. If you wish to keep the intended sonic design, then select the
amplifier’s impedance at ½ (half) the value of the speaker load when in half power mode.
For example, a 16 ohm speaker cabinet plugs into the 8 ohm LOUDSPEAKERS jack of
the amplifier. You can also turn the optional FX LOOP into a volume boost, a second
master volume if you will, by taking a small instrument cable and jumping the SEND and
RETURN jacks in either SERIES or PARALLEL mode. Then using one or both controls,
engage the loop on and off to adjust your level of volume boost.
