RedPlate BlackMagic Operations Guide
5
POWER ON/OFF PROCEDURE
1. Check the Standby switch to make sure it is toggled downward for Standby operation.
2. Toggle the main power switch to the up position (this switch is located at the top of the IEC
input module). The front panel pilot light should be lit.
3. Wait one minute and then toggle the Standby switch upwards to the Operate position.
4. POWER OFF
– Toggle the main power switch downward, there is no need to go into
standby first although it will not hurt anything.
MAINTENANCE SECTION
Your BlackMagic amp has been designed for years of trouble free operation. The vacuum
tubes will need to be replaced over time. We recommend new output tubes every 160 - 240 hours
and new preamp tubes every 320 - 480 hours.
The front and rear panels have a protective finish that can be easily scratched with abrasives
so always use a damp soft cloth to clean them (never use paper towels).
TUBE LAYOUT
All tube brands are acceptable, a long plate is preferred in the V5 (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 6L6GC 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.