Hi, i got a Unison Research S9 integrated amplifier, recently my amplifier suddenly muted when listening to music half way, then i switched it off, waited for around 30 minutes and switched on again, to my surprise this amp can be played lik usual, but i found the V2 bias no longer available, i pressed all the Valve bias switch, V1, V3 and V4 is normal, but V2 shiw nothing, i even tried to adjust the V2 bias, but stil the same. Would like to ask what is happening to my amp, will it be the V2 damaged, hope any sifu can hep me on this problem!
A bit late to the discussion but did you ever find out what the problem was? I just bought an Unison S9 and the 3rd tube just went dead on me after the first week. The tube itself works fine in every other socket but not in the 3rd. Fuses seem fine since the 4th tube lights alright. Curious if I may have the same issue and if there is an easy fix.