Standby hum/noise?

[Structo]

Not sure about the OT you have, but when I upgraded my OT iron I went with a Prosonic OT from Angela.

It is a pretty hefty OT for 50 watts.

It could just be the fact that your OT is an open frame transformer and it is not shielding the flux as well as one with end bells.

I don't see your grid resistors on the power tubes, are they in the middle of the socket?

And, are the Vishay resistors on the power tubes the 100 ohm virtual center tap for the heater supply?

I wish I could think of something to try but it really does look like a pretty well dressed amp.

[Guitarman18]

Hi structo,

I think you are right about the lack of end bells adding to my problem, but that's life I guess!!

I don't see your grid resistors on the power tubes, are they in the middle of the socket?

The control grid resistor are the ox blood coloured Vishays you can just see, connected from pin 1 to 5 and yes, the flesh coloured resistors are 100 ohm, 1% flameproof 2W Dales for the artificial centre tap for the heater supply.

I'm gonna pull the OT and see where it wants to be using the 'headphone trick'. If I end up having to mount it in the next room to reduce the hum I'll have to think again. .

Apart from that one issue, this is a great sounding amp and beautifully quiet when in use, well worth the effort!


Cheers,

Paul.

[Structo]

Well it certainly is a fine looking build, too bad the OT is giving you grief.

I wonder if a choke would help with the hum?

[Guitarman18]

Thanks!

I'll keep you posted!