Revv Owner’s Manual - 16
Procedure:
1)
If you are simply checking the bias, use your multimeter in the bias test
points to verify that the tubes are at the recommended bias setting. If the
bias setting needs to be adjusted or new tubes were installed, remove
the D20 top lid to access the tubes and bias control trimmer.
2)
If you are changing tubes, change them now, make sure that the power
cable is unplugged from the amplifier.
3)
Once the tubes are replaced, or you are ready to adjust the bias. Plug
the amplifier back into the mains and turn on the power switch. Make
sure the D20 is connected to a speaker or the reactive load switch is set
to internal load. Let the amplifier warm up for a minute then turn on the
standby switch.
4)
Wait another 3 minutes to let the tubes warm up further. Make sure
your multimeter is connected to the bias test points on the amp. Now,
using the bias adjustment trimmer (located in the small hole inbetween
the power tubes) turn the trimmer until the required reading is visible on
the multimeter.
5)
Once the bias is set as recommended, turn the power off on the D20.
Wait until the tubes are cooled off (approx 10 minutes), then put the top
lid back on the D20, fastening all 4 screws securely.
BIAS CHART for D20
Type
6V6GT
Recommended set point
50mV
4.1