How to bias Audio Research VT100 MKIII?

I have a ARC VT100 MKIII,it's time to replace tubes and rebias the amp, but I don't know how.
Any one have done this please give me some advices.
Thank you very much,
Biasing This amp is easy and Dangerous. I have 30 years experience in electrical/electronics. This baby can bite, my hand hurt for 2 days. I think it is 575 Volts inside the case. Be sure you know how to use a multimeter, and you have good 1000V leads. A nice Fluke or equiv. If you are not sure, send your amp in to ARC and they will do it for you. I sent mine in for new tubes and they found a problem in the turn on circuit and fixed it for free.

Call ARC first and they will tell you how to ship to them.

Jim G.

Shipping is very expensive, more so if you ship from Canada.  Very few dealers left here with proper service.


To all thinking of DIY tube replacement: don't!  Let a qualified technician with experience on tube amps do the work.


Don't mess around with the high voltages under that hood!