Eeyore wrote:

Arfa Daily wrote:

"Eeyore" wrote in message
...

N Cook wrote:

Cured the main problem but the owner seems to live with what to me seems
an excessive amount of stray mains interference, without any signal leads
and input contacts shorted to ground.
This amp is 110V running off a 240/110 V autotransformer with the chassis
having an earth to mains earth (UK)
Probably illegal and should almost certainly be linked out. You might want
to consult your liability insurance

I don't think I'm following what you're saying there. Explain ??

I misread it as a chassis to mains earth switch. Such things have been known.

What DID he mean by " with the chassis having an earth to mains earth " ?

Either the chassis is earthed (grounded) or it isn't !

Graham



As I understand it, he used an autotransformer to step down[1] the UK
mains to 110, then fed the amplifiers own mains tranny from that, adding
an earth wire from the amplifiers chassis to mains earth. His general
complaint has, I believe, nothing to do with the mains supply
arrangements, rather interstage noise generated by the vibrato/reverb
circuits etc.

[1] probably incorrect term I know. I`m sure someone will soon be along
to set me straight. ;^)

Ron(UK)