Re-tubing my Audio Research Ref 110


After taking advice here I've ordered 8 matched KT120 valves and 4 6H30 (getting difficult to get as can't import from Russia now!)

I've read the ARC instructions but want to make sure I've understood correctly - don't want to blow it (or me) up.

I turn it on for 15-20 with the speakers connected but no signal going through (so disconnect the source or mute?)

The I attach the multimeter, one to the yellow and one to the black beside each pair of tubes/valves. Does it matter which wire goes to which?

Then I turn the blue screw (guess the one adjacent to each set of the two tubes is the one?) The manual says I need to adjust to get 0.65V DC on the meter but that's for the original spec 6550 tubes. Is it the same for KT120 tubes?

And do I just stick the other 4 x 6H30 tubes in - do they need anything?

 

 

 

willmarchant

Showing 1 response by audphile1

Do the KT120 just drop in as a direct replacement for 6550c?

Did you contact ARC to confirm this and to find out what the KT120 should be biased to? 
 

Other than that, @jasonbourne52 provided the steps. Just have you source(s) powered off when biasing to be on the safe side.