"Keith G" wrote in message
...

"Keith G" wrote


Found the hum on the AEG Solidtube tonight - after swapping 3 valves to
no effect, I thought it was a poor earth connection on the casing at one
point as it could be temporarily affected by gripping it here and there.
Then reading the service .pdf that someone kindly put me on to (Ian?
Iain? - I'm on a different machine, so I can't see who it was) I checked
and found it was the bass attenuation switch:


Typing ******** as usual - its a -20 dB 'pad' switch!


The sun always shine on the righteous, they say - let's just hope it
don't *hum*...!!!


OK, not so righteous it seems - the hum has become erratic and irrational
and it hums with the switch the other way now, so I guess it's gonna have
to go off for a pro repair.

(Too fiddly and will probably need parts....)


Before you send it off. A colleague tells me that this mic
has a spring through which the case is grounded.
Check that it is making good contact.

Iain