Bias adjustment

Typo Field Flukes 

Typo They "did" hold a good Bias, smoked um... Cable drop...

VTL are broke, not working, capoot, crashed, burned, killed um'.
You feel bad.. Yours is easy to fix.. Mine is a friggin' nightmare, TRADE YA!!!!!! 340 WPC, POOF!!!!

16 valves, setting there looking like 16 valves setting there...

Hope you can see the humor...

Regards

In reference to adjusting the bias on vacuum tubes, I have a question that no one, no manual, no tech has brought up and I am really interested to know. It is simple: When someone tests or adjusts the bias using a VOM or mA meter and the amp is ON with all vacuum tubes in place.......
1- Should the measurements and adjustments be made with NO load on the amp? In other words no speaker leads connected; no sub-woofer connected?
2- With everything connected and functioning?
Why? Is it possible one gets a different reading and how much difference if there is a load or not?  Any thoughts on this?

Biasing can be performed, with or without input connections, but- with a load on the outputs.      Otherwise (no output load); one can lose a transformer.      Nothing (no signal/music) playing, while being done (amp at idle/you’re setting it’s, "idle current").     Amp should be warmed up (maybe 30 minutes), before checking/adjusting).

Oh my goodness.  If what you are stating is FACT (and I do believe you) then in both cases on my different amps I have been measuring the bias INCORRECTLY.
1- On my SLA-70 Signature amp - which weighs about 50 lbs and sits on a top shelving unit - to test the bias I need to disconnect the speakers so I can take down the amp and place it upside down to unscrew the bottom plate and then proceed to check the bias [as it is inside the amp].
2- On my integrated amp SLI-80 the jacks are on the top so all I need to do is to insert the plug and read and adjust the bias.  And I have been doing it with music playing.

In either case, neither the techs from Cary nor the service manual mention anything regarding "how to" with the exception of where the bias should be.
Thanks for your input. I appreciate it.
Richard

So it appears that the Cary tech was correct.  Your readings were wrong. I have to say, due to poor communication with the manufacturer you end up proclaiming that you'd never buy a Cary product again if your life depended on it despite the issue was user error as Cary correctly pointed out.  Ugh.

I didn't even think that anyone would consider setting bias with music playing. Yes, you want your speakers connected when you check bias but DO NOT play music while measuring. The whole point is that you're checking the bias while the amp is at idle, and running a signal through the amp is not idle. Depending on how you had the volume knob set you could have easily been running the amp 50mA or more ABOVE idle when you were measuring and hence frying your power tubes.