Hi Martin, thanks for your reply.
I have checked the balance.
the channel does pop on start up and there is some sound which is faint and crackling but in camparison to the other channel you can hear there is omething wrong. Since my last post I have left the 901 with a guy who may be able to fix it and I am waiting to hear back. Also, I have just purchased a tape deck Beocord 1101 which gives me a really lovely set up. so looking forward to having it all up and running. The tape deck has a teak finish so I might replace it with rosewood to complement the rest of the system. Very exciting lol, when it all works.
I'll let you know as sson as I hear from the repair guy about the 901 and take it from there. I am hoping to that he will be able to replace the bulbs which have gone...
cheers
james