Weber Bias-Rite - Should I get one with Octal and 9 pin?

[Craftmatic]

I ask because I need to bias an amp with octal power tubes (6V6) but I am wondering if I ever get an EL84 amp someday - do they need to be manually biased too? Or are most EL84 amps cathode or fixed bias?

[phsyconoodler]

There are both cathode and fixed bias EL84 amps out there,but you will likely not run into many fixed bias ones unless you are doing repairs for a living.
For the extra few bucks it's probably a good idea.

[Structo]

I don't know about that one.
I think there are a few 4xEL84 fixed bias amps.
The Carvin Belair for one.

[Craftmatic]

There are both cathode and fixed bias EL84 amps out there,but you will likely not run into many fixed bias ones unless you are doing repairs for a living.
For the extra few bucks it's probably a good idea.

But cathode biased EL84 amps don't need to be biased. Right? And fixed biased can't be biased (unless you change circuit values). So what else is there in 9-pin tube based amps that would need manual biasing (with a meter and a trim pot)?

I'm not that up on electronics.

[Craftmatic]

Anyone else?