RT2/50 Tube Layout

[destratification]

I know there are a lot of rt owners on this list. Anyone know definitively, looking at the back of the amp, which power tubes are chnl 1 & chnl 2? I screwed up the bias settings with a poor multimeter and don't want to overheat or damage tubes by listening for the difference. Got a new meter and ready start over. I searched on the randall forum but found differing answers... thanks.

 

[jkdsteve]

Looking at the back of the amp:

Power tube pair on the left is Channel 2, right pair is Channel 1

I found this out simply by turning the bias, volume etc. all the way down, power off and pulling a tube pair....when you power back up...the missing pair has no bias reading

I believe the ax7s immediately between each pair is also the phase inverter for that pair....maybe the other ax7 (directly in the middle of the other two) is used as a signal buffer?

 

[jmgman69]

I know there are a lot of rt owners on this list. Anyone know definitively, looking at the back of the amp, which power tubes are chnl 1 & chnl 2? I screwed up the bias settings with a poor multimeter and don't want to overheat or damage tubes by listening for the difference. Got a new meter and ready start over. I searched on the randall forum but found differing answers... thanks.

Channel 1 is if looking at back of amp(right side)

 

[destratification]

now why didn't I think of that
thanks jkd