Tube Amp Bias Test Adapter for power tubes 6V6 6L6 EL34 6550 KT88 7027 or 7414 to measure plate current for biasing purposes.

You only get the bias tester shown just below the tube (it has red and black leads coming out of it), thats it, not the big jackson tester, not the digital meter.

Usually you'd plug this bias test adapter into an amp.  You must set your meter to ma (milliamps), i.e. you can see this old 6V6GT read 30.0 ma.

Again, you only get the test adapter with meter leads, it weighs about 2 ounces, not everything shown.

Instructions- Turn your amp off.  Turn your meter to ma scale.  Plug the test adapter into your meter and plug power tube on top.  Turn on amp (minimum volume).  Read current after it

stabilizes after about a minute.  You may wish to adjust your bias.  Turn off amp and let amp sit several seconds before removing test adapter, and returning your power tube as normal.