Slight buzz from my Bogner 100B?

[67Mopar]

I'm getting a low-level buzz through my speakers when I take my 1993 Bogner 100B off of standby. It has never had a capacitor change, so I'm wondering if this is the cause? Where can I order these small style capacitors if they need to be changed? The buzz doesn't get louder as I turn it up, so it's more just an annoyance at this point.

[ryu]

I'd check the usual suspect first (tubes)
when you play elsewhere is the hum still present?
it might just be a light radiating or if you have something else plugged into the same line like a washing machine or something like that
18 years old cap surely need a change

[67Mopar]

I'd check the usual suspect first (tubes)
when you play elsewhere is the hum still present?
it might just be a light radiating or if you have something else plugged into the same line like a washing machine or something like that
18 years old cap surely need a change

Thanks ryu. The buzzing continues no matter where I have it plugged-in. I can hear a light physical buzz from the PT, then that buzz seems to be transferring itself through the speakers when the amp is taken off of standby. I assume this is caused by the windings in the transformer? Poor filtering? Combination of the two maybe? I have a quad of RUBY EL34 BHT's that I will try today. I tried two quads of "S" Svet's in the 100B, but the buzzing remained.

An observation:
The BHT tubes are suppose to be able to handle the higher demands of the early Bogner amps. When I tried the BHT's in my white-chassis '95 101B, they began to red-plate when switched to Class A! The bias read 60mA when I tested it with my Bias-Rite in Class A mode. I have "S" Svetlana's in the 101B now, and those seem to handle Class A just fine. I have heard that changing the Class A load resistors from 270 Ohm to 300 Ohm takes some demand off of the tubes...?

[ryu]

a slight hum (physical) from the PT is normal, maybe try to tighten it back, with vibrations sometimes it can get loose
but from what you describe I'd say try changing your filter cap, you'd better do it anyway
I liked svet C and ruby bstr with the 101, bht are marketed as being bstr that can handle higher plate voltage but they really don't sound the same IMO

I didn't experiment with the class a mode, maybe PM joey on this board about that

[67Mopar]

a slight hum (physical) from the PT is normal, maybe try to tighten it back, with vibrations sometimes it can get loose
but from what you describe I'd say try changing your filter cap, you'd better do it anyway
I liked svet C and ruby bstr with the 101, bht are marketed as being bstr that can handle higher plate voltage but they really don't sound the same IMO

I didn't experiment with the class a mode, maybe PM joey on this board about that

Thanks. I did send Joey a PM earlier today. He's THE MAN when it comes to tech stuff!

[67Mopar]

I found it. The buzz was coming form the effects loop.

[ryu]

what is it exactly?