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)
Other than probably something to do with the awkward cross-linking of the 2
sections of 2 7025, of normal and vibrato channels . It is possible to
minimise the noise using one "normal" signal input and nothing in the
"vibrato" inputs but the vibrato volume set on about 3 of the scale, not 0.
Is there a recognised fix/amelioration of this effect. ?


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Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/