There is some basic stuff here showing parts replacement.
http://www.chambonino.com/work/hifi/hifi5.htmlSome original Leak info here:
http://www.44bx.com/leak/varislope1.htmlYou will probably have discovered that most Leak power amp users don't like them. I tried mine with the TL50's but didn't either. All the phono EQ options (of which there are several on some models) sounded harsh and very noisy. There is too much gain for most line sources. See info at above site.
Classique Sounds in Leicester strips them out to make passive preamps so the box looks good in a Leak system. Slightly desperate solution.
Good Luck