Noisy Avalon 737SP.... how noisy should it be

[Martin Quinn]

I got an Avalon on Ebay abroad and when I plugged it in I notice that its
noise floor is about 20 dbs louder than it should be. Theres a hissing,
'rustly' sound coming through. It comes up the more you bring the Mic Pre
input up. I sent it to the repair shop and the repair man told me that it
was a dodgy valve, which he replace, then charged me ?50 for the job.
Brought it home, plugged it in, still the same.

Before I call him back I need reassurance that I'm not goin mad. I have a
Great River MP2NV, a Focusrite ISA430MKII and 2 TLA 5051 preamps. plugging a
bass guitar into these at the same sort of level shows me a signal thats
significantly quieter. I've tried different wiring too (that was my first
thought) but its still the same.

This is the only one I've heard. Should a 737SP be damn quiet for the money!
And could it be bad valves or a dodgy transistor on the input circuit?

thanks guys,

Martin