RedPlate CDS3 Operations Guide
Page 6
©
RedPlateAmps 2012
All tube brands are acceptable, a long plate is preferred in the V6 (Phase Inverter) position. The Overdrive tube is also
the Tweed preamp tube. 6V6GTA can be substituted for the 6L6 GC tubes for less wattage (cathode mode only) but do not
mix the 2 types.
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 6L6 GC output tubes are installed it is important to re-bias the amp for optimal performance. No biasing
needed for 6V6 tubes because they can only be used in cathode bias position.
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 read lead is the DC voltage terminal of the meter.
4. Place the Amplifier in operate mode with the Master Volume and Reverb controls set to zero.
5. Set the 50 WATT/ 40 WATT switch to the 50 WATT position (Fixed Bias mode).
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 a reading of 72MV ± 5 MV (FYI - the plate voltage is 470
volts). The reading is the sum of the idle current for both tubes.
8. Recheck the reading after 10 minutes of operation, and again after a week or two of operation.
INTERNAL TRIM POT
The CDS3 has 1 internal trim pot for the PI Balance
– Useful for working with unmatched 12AX7 tubes in the phase
inverter position. Refer to qualified personnel for proper setting.
RedPlateAmps Warranty
At RedPlateAmps we pride ourselves making products that are built to last. The workmanship in your RedPlate amplifier is
warranted to be problem free for the lifetime of the original owner, or in the event of resale a onetime transfer to a new
owner for coverage for 3 years from the original manufacture date (please inform us of an ownership change to insure
coverage). The actual electrical components in your amplifier are warranted for a period of 3 years. Exclusions are vacuum
tubes, reverb tanks, cables, speakers and cosmetics which are warranted for 30 days. Improper handling, product misuse,
product abuse, unauthorized repair work or unauthorized modifications may nullify your warranty. Eligibility for coverage and
covered items are at the sole discretion of RedPlateAmps.
RedPlateAmps
1812 W Cinnabar AVE
Phoenix AZ 85021
www.RedPlateAmps.com
email:
Thanks again for joining the RedPlate Family
– Henry