RedPlate ShredPlate Operations Guide
6
TUBE LAYOUT
All tube brands are acceptable, a long plate is preferred in the V6 (Phase Inverter) position.
Warning
– No user serviceable parts inside so unless you know what you’re
doing please refer to a qualified service person only.
BIAS PROCEDURE
1. When new EL34 output tubes are installed it is important to re-bias the amp for optimal
performance.
2. ALWAYS HAVE A SPEAKER CONNECTED.
3. Use a digital volt meter set to DC volts at lowest scale (MV). Makes sure the black lead is
the common terminal of the meter and the red lead is the DC voltage terminal of the meter.
4. Place the Amplifier in operate mode with the Master Volume set to zero.
5. Set the 100 WATT/ 50 WATT switch to the 100 WATT position.
6. Place the red meter lead in the test point hole (red tip jack) and touch (or clip) the black
meter lead on one of the metal output tube retainer clips.
7. Use a small flat blade screwdriver to adjust the bias pot for the bias number as stated on
the rear panel ( ± 5 MV). The reading is the sum of the idle current for all 4 tubes.
8. Recheck the reading after 10 minutes of operation, and again after a week or two of
operation.
INTERNAL TRIM POTS
The ShredPlate has 2 internal trim pots:
1. Clean Headroom
– can be adjusted to match your guitars pickup output so your clean tone
has the desired amount of character.
2. PI Balance
– Useful for working with unmatched 12AX7 tubes in the phase inverter
position. Refer to qualified personnel for proper setting.