You can get a PDF manual here:
Call 919-355-0010 and ask for a tech. Gerald Walsh is very helpful. Ask what the bias should be set at. Sometimes it differs a little from the manual. Speakers should be hooked up. How hot do they run? I just traded in a Cary V12R amp (they run very hot) that I really enjoyed on a new Cary 120S amp. I still can't beleive how good it sounds. The bias on the V12R was set at 238 and the 120S is set at 150 and has the meters built in so you just need a screwdriver. Be careful not to turn the screws much. 1 or 2 degrees makes a big change, so call Cary to get the right specks. If the amps are good, you're going to love them. Good luck. polk432
I haven't owned these, but certainly the amp has to be turned on. It's not clear if you need to unhook the speaker cables and/or interconnects. FWIW, the parent company (Cary) suggests disconnecting the amps from speakers and sources before biasing, though on my Cary SLI-80 I have occasionally checked bias with everthing connected. I would caution that many amps require the speakers to be connected while in operation, so I would suggest contacting AES.
FWIW, here are the Cary intructions for their amps.
How do you correctly bias a Cary Audio vacuum tube amplifier?
I spoke to Gerald about the very same thing. He said that it's ok to insert/remove the plug into the bias jack while the amp is on....your speakers may not like it, but it shouldn't cause any harm to the amp.
I initially followed the directions in Cruz123's post, but since have had no problems just plugging/unplugging the test jack while the amp is on. I do have my multimeter already turned on and set to the correct range BEFORE I plug in the test leads. The suggested bias point for the Six Pacs is 220mA.
Roblanger, the multimeter supplied is set by the seller (?factory) to 200mA and reads only up to 10. About half way turned reads 2.3. But shouldn't it be 0.2 (there are only 3 LEDs, 00.0, so the theoretical maximum it reads is 10.0.
So, to read 230 mA, should I read 0.2 or 2.3???
I've asked this of Gerald, too, but I dont know if he followed me! Do you? Mathematically, it should be 0.2, which is 200 mA, but that doesn't seem right, as the bias goes all the way to nearly 10.
FWIW, the amp can be biased without speakers and inputs attached. Per bias instructions supplied by Gerald at Cary. I gave up on the useless Multimeter and bought an analog meter which measures up to 500 mA, just as you have.
Problem solved. Thanks again! But I wish I knew how the previous owner biased his amps with the supplied multi-meter.