Another Valve Limiting Amp question

[blackfoot]

Last year as part of a job lot I picked up an elderly Langevin Valve Amp converted to a 6386 based limiting amp with attack & release controls. The amp wasn't my main interest in the sale so I haven't paid much attention to it. I've recently listened to it & it's pretty nonlinear & unpredictable with a slight hum. My local tech had a look & came away shaking his head. Anybody had any experience converting something like this? Is it just somebody's folly & not worth pursuing? Or could It be a one trick pony & I haven't found it's trick yet? I'd really appreciate some advice.

[Kurt]

Maybe it's trick is to hum and be unpredictable?

[Chris H]

Re the slight hum , if it's in a rack next to other gear, try it out of the rack to see if the power supplt of the gear next to it is causing the hum.
Next i would get someone like Rob or Andrew Kay, familiar with vari mu design, to check it out, draw a schemo etc to see what the design is, see if it's worth perusing to do any necessary repairs, adjustments and mods.