Post by daddyelmis on Sept 15, 2018 9:32:17 GMT -7
any body have any experience using this bias tool? I only have one amp that requires biasing (my Z28), so investing over $100 in a bias tool doesn't make a lot of sense to me, and I'd prefer doing this myself as opposed to taking to a tech (of unknown experience or quality). I'm comfortable working around my amps. I do have a multimeter but is a low cost one with the probes wired, so just buying the octal sockets would require getting new MM's.
Anyway, this device seems to do what I'd need, I've just never heard of these guys and there's not much in the way of reviews out there.
Post by premiumplus (Dave) on Sept 15, 2018 18:06:17 GMT -7
You can get just the socket/banana leads portion of it and use your existing multimeter and hook it up with clip leads...it's measuring cathode current so it's low voltage. Tape it up if you're nervous. If I were buying one with meters I'd go digital for better accuracy. Mechanical analog panel meters typically have errors between 1% and 3%. You can get a multimeter for $5 that would be more accurate than those panel meters would be, they have them on sale at Harbor Freight all the time. All that said, If you are at all serious about working on tube amps, invest $100 on a decent Fluke meter.
"Tone, tone, tone, tone. Is there a substitute?" -Dr.Z
Douk Audio is a Chinese company so take that for what it is worth. They have a LOT of different kits for sale on the web. I have a couple of those HUA meters in some projects I've built. They seem to work OK but I wonder how robust they are so I wouldn't want them in something I hauled around. Also, in order to properly set bias current I like to monitor plate voltage at the same time. One more thing. Those meters aren't going to give you the resolution you need to accurately set bias.
Last Edit: Sept 16, 2018 15:03:29 GMT -7 by zpilot