After over 13 years my Beresford TC-7510 has developed a fault. The right channel has slowly been showing signs of distortion which is now a permanent presence rendering the unit un-listenable.
The distortion is apparent via the units headphone socket and when being fed via an amp to speakers using coaxial or optical input.

Anyone got any ideas what the issue might be?
Is it worth fixing?

Thanks in advance,
Steve