BIAS TUBES VM220 ARC

I am not familiar with your amp, but what are your trying to measure? Most tube bias are in the mili-volt range. Are you trying to adjust the bias pot to read 65 mv? It sound like you multi-meter is on the wrong setting.

Hi, sorry for the typing error. Yes i am trying to adjust the pots to read 65 mili-volts. all the other pots i can adjust properly only #v1 and #v2 i get weird readings thanks

Sounds like a bad or poorly matched tube-set. Try switching the offending pair to the other amp and retry. When all is working well, this should be an easy adjustment.

Wholesake, how did you make out with the tube switch? I own an ARC VS-115. Tube switching may help and I hope it does. If not, the problem could be a blown bias resister. I have had to replace bias resisers twice already. Bias resisters often blow if a tube arcs. Please let us know how you make out.

The tube switch did not work, I still show very low readings. in #v1 on one amp and #v2 on other. How do i know if the bias resister is blown? Where do i get them at? and is it easy to do myself. thanks I thought the tubes might be blown, so I order a set (octet) x2 TUNG-SOL KT 120,should i try them first or just replace the resister?