Bias Procedure - RedPlate RP50D Operation Manual

RedPlate RP50DUO Operations Guide
Warning – No user serviceable parts inside so unless you know what you're doing please refer to a qualified
service person only.
1. When new 6L6 GC output tubes are installed it is important to re-bias the amp for optimal performance in the FIXED (50 WATT)
mode. 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 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.
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.
RedPlateAmps Warranty
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 warranty 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 or product misuse or product abuse or 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: info@RedPlateAmps.com
Thanks again for joining the RedPlate Family – Henry

BIAS PROCEDURE

At RedPlateAmps we pride ourselves making products that are built to last. The workmanship in your
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