19-08-2026, 01:30 PM
Anecdotally, I've found the Lockfits to be fairly reliable in these later sets - not perfect, but certainly better than in earlier sets like the Sov2. No idea why, but perhaps Mullard improved their processes?
I'd also be wary of the AC187/188 output transistors (and the bias generator TR3, which is a "T2", which is probably an AC128 or something that didn't meet the voltage spec) - they can suffer from tin whiskers.
But to be honest, the least reliable part of a Sovereign III, including all related sets like the Knights, is the connectors - especially the amplifier connection. They seem to be even worse then the circular 5 pin connectors that causes so many problems with the earlier sets.
And switches and headphone sockets are definitely in the frame. As are the pots (including the power switch on the volume control).
Generally, most faults with these sets are simple things like that. I've needed to do much less component-level diagnosis on these compared to earlier models. Several random faults were caused by oxidisation on component leads (between base metal and plating), but that's not unheard of elsewhere.
I'd also be wary of the AC187/188 output transistors (and the bias generator TR3, which is a "T2", which is probably an AC128 or something that didn't meet the voltage spec) - they can suffer from tin whiskers.
But to be honest, the least reliable part of a Sovereign III, including all related sets like the Knights, is the connectors - especially the amplifier connection. They seem to be even worse then the circular 5 pin connectors that causes so many problems with the earlier sets.
And switches and headphone sockets are definitely in the frame. As are the pots (including the power switch on the volume control).
Generally, most faults with these sets are simple things like that. I've needed to do much less component-level diagnosis on these compared to earlier models. Several random faults were caused by oxidisation on component leads (between base metal and plating), but that's not unheard of elsewhere.
