[Don Maico]

One of the input valves seems unsteady that is one channel does not work too well without twiddling the relevant valve around. It either hums, makes a scratchy noise or nothing. My guess is that the valve seat needs replacing

[roymail]

http://hotglassaudio.com/home.htm

[bulgin]

Hi Don

I'm a longtime Leak Stereo 20 user. My guess is that it could be a "Leak"ing cap problem. Here in South Africa, we have a marvellous guy Wim Bouwman (aka Mr Valve), resident in Johannesburg. Wim is also a Stereo 20 fan and has a cap replacement kit on 2 pc boards, supplied complete with d/sided tape backing, which fits underneath out of sight. The idea is to leave the old caps and their cans in place but disconnected and replace these with Mr Valve's cap sets. Mine has been tweaked this way some years back and it was the best change I ever made.

I'm sure if you google either Wim Bouwman or Mr Valve, you'll find his email address.

Cheers

bulgin

[timothyharnett]

One of the input valves seems unsteady that is one channel does not work too well without twiddling the relevant valve around. It either hums, makes a scratchy noise or nothing. My guess is that the valve seat needs replacing

Are you in North America or elsewhere?  In the UK you'd use either Classique Sounds, London Sound or GT Audio.  I use Classique for my St 20 - Paul is a Leak specialist.

The good thing is that ST20s are cheap to repair.

[Don Maico]

Thank you for your reply