Amp tech/Bias question regarding bias probes

[maddnotez]

Looking at getting the Eurotubes newer ET One bias probe. I think i may have the old, very cheap version where its just the tube socket with wires that I attach to my own meter but I'd have to search for it and I really like how the ET one has it's own digital meter connected, I need dummy proof. Plus you can play the amp with it connected safely which is a huge bonus to me. (Can you do that with others?)

My problen is that the ET one only has one single octal head and this kind of bothers me. I could be wrong but I think back in the day they had one with 2 heads or even 4?

Im curious if this will be an issue for a complete noob like myself, I want to find a probe that has 4 heads so I can bias them all at the same time or at the very least 2 heads for basing in pairs. My ignorance makes me think wow, why would they not offer this? How freaking dumb......but im a noob and surely im missing something here.

I see other units out there with 2 or 4 heads together i could buy instead but the thing is I REALLY like the Eurotubes version with the digital meter that shows the plate voltage and plate current and all of that. Again, I want this as dummy proof as possible.

I have biased my own amps a couple of times before. I do not like doing it at all but im smart enough where I shouldn't die. Would much rather bring it to my local tech but im in a serious time crunch at the moment where doing it myself is the only thing that makes sense so yeah, was just curious about pros and cons with the ET One and doing one tube at a time and being able to play the amp with it connected vs biasing in pairs.

 

[greatmutah]

The ET one is probably fine. Does it take a little bit longer? Sure but bear in mind a couple things. Unless your biasing each tube individually you’re probably going to be doing either a pair at a time or all 4. Select one and get a read, check and set your bias and let it sit for a bit. Power down the amp and move the probe to the next tube. Check and measure readings. So long as nothing is red plating you’re good and as long as the tubes fall in range of +/- 5 mA of each other you’re good. That’s why we have tube matching these days, though how well they’re matched depends on the vendor.

 

[greatmutah]

FWIW my bias probe is a single octal socket from a bias master that George Metropoulos gave me at his shop and I set up a RCA adapter to run to my multimeter and it works great. I’m also doing one tube at a time.

 

[GuitarBilly74]

Most amps have a single bias pot for all tubes anyway. So as long as you have a good matched set, biasing it off one tube is enough.