Bias adjustment


I need to set the bias on my vacuum tube amplifier.  Does anyone know where I can BUY an amp meter that reads milliamps?  Most I have seen are for large AMP applications.
128x128richfrank
I bought a Fluke multimeter with a hard case for $45.00 on Amazon. Got it within 3 days.  Fluke is one of the better brands.  
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