Beard P.101, new-to-me.

[rileydriver]

I've recently acquired a Beard P.101 amplifier & could do with some advice.
I have no handbook & am puzzled by the biasing arrangements. The power end of things is a rank of 8 6500's, with green LED's which glow brightly at switch-on, then go out randomly... usually... though one may stay on. There seem to be rheostats beside them, presumably for bias adjustment, but I don't know whether the adjustment is supposed to be to 'glow' or 'no-glow'

Does anyone have advice - or a handbook, please?

I am old enough to have grown up with tubes (or 'valves' as we quaintly call them in the U.K.) 7 'mains hum' was something we accepted as part of the experience of listening to the 'wireless' in the 1950's. I had hoped that with a modern(-ish) design this would be a solved problem: no such luck!
I seem to suffer with two hums; one is mechanical, making the cabinet buzz quite intrusively, the other is a constant (unrelated to volume) hum through the 'speakers.
I have checked that everything is earthed (once, not twice & all at the same outlet socket) & it is still present, though quieter, with no input at all connected.
The noise isn't very loud, but is intrusive; do I have to live with it (which will probably actually mean that I return to 'solid state') or can anyone help?

Thank you.

[Alettagla]

I dont"t know the p1001 but I own a Beard p100. Anyway this method for biassing is quite common. The biasing procedure is as follows. Turn al bias controls completely anti clocckwise. (LED"s Go out). Then start biasing each tube one by one. You do this by slowly turning one of the controls clockwise. When LED goes on you imediately stop. Next you turn it anti clockwise again until it just turns of . and thats all This procedure you repeat for al tubes.

BEWARE when the leds keep glowing it means your bias setting is far to high so you will very quick damage your tubes. Since the standard bias setting
with the above procerure is already very high for these tubes.
I regurly check if one of them is not glowing permanently

But congratulations you have an incredible amp!!! unfamous but one that can compete with a lot of famous amps out there.

Somewhere on this forum there is also a schematic of the p100

[rileydriver]

Thanks. I took the lid off & made adjustments after allowing an hour for warm-up. Surprise no.1; not all the adjusting rheostats seem to turn the same way! One adjuster seems to go round & round again (with a click, sometimes) but doesn't seem to alter the LED, which remains dark. Surprise no.2 (I should have remembered this from my teens); re-biasing one valve can alter others - rather like balancing carburettors used to be. When I got it wrong ( wrong direction of turn for one adjuster) I was rewarded with a really brightly glowing valve & a blown HT fuse - doing its job protecting the valves from their foolish owner.
Third surprise; hum improved... a bit... then it returned.
Re-biased again today - small adjustments this time, no blown fuses, no burnt fingers!

Any advice about the humming? Should I consider changing from 6550's to EL34's? I'm inclined to leave well alone at present & just enjoy my new toy, but it would be more fun with less hum!

[Jorge Vaz]

Hello!!

Anybody have a service manual for Beard P-101,
Please, I buy it.
Urgent

Best ragards

Jorge Vaz

[Jorge Vaz]

Thanks for your help.
My email is: ct1iaz@gmail.com

The best for you

Jorge Vaz