Can i bias an amp with anything other than a bias probe?

[Young Angus]

Okay so ive got new tubes to put in my ENGL, but i dont have a bias probe and dont really know where to get one short of ordering one in from overseas.

I do however have a dad that works for the Australian Broadcasting Corporation and has access to all sorts of technical broadcast test gear and such, including oscilloscopes, which i heard a while back can be used for biasing but i dont remember what context i heard this in or even if it was right.

So whats the deal? Ive got a scematic of my amp which tells me where everything in the guts is, so can i bias it by using another tool bar an actual bias probe or should i really just bite the bullet and get a probe.

I will get a bias probe so that i can continue to bias my amps, but just for now i want to get my ENGL running with the new tubes, so is there a way to do it?

Cheers

[Kent S.]

Re: Can i bias an amp with anything other than a bias probe?

Yeah, the preferred way, with a dummy load (for the amp speakers, proper wattage and impedance for the amp),a y-cable, a variac (to set to input voltage exaclty to the amp ... some consider this nitpicky and optional),a sine wave generator (or full function generator), an oscilloscope, and an input cable from the function generator to the amp input. The proceedure is straight forward enough, hit any amp sight for a walk thru, or better yet buy any tube amp maintenance book. Be careful, pay attention, and use common sense as well as all safety protocols.