Mystery Amp

Mystery Amp?

2 x EF86, 1 x ECC82, 2 x EL84, 1 x EZ81 - Possibly a GEC.

I can't find anything about this amp on the Internet. Luckily it has the circuit diagram stuck inside the bottom plate. I would love to know the maker, but there are no makers marks anywhere, not even on the diagram. However, it seems to me to be very well built, and the designer included test points too. All I have done is clean it up, deoxidised the valve pins, sockets and pots, added an IEC socket with earth lead to the chassis and a jack plug socket to the front after removing the blanking plate. It sounds really good for guitar in the Mic channel, but even better with an ECC83 instead of the stock ECC82 in the PI position. I can't believe there is no hum whatsoever, even though the original Plessey filter caps must be knocking on 50 years old. It is a little bit hissy as you would expect, but it's not really noticeable. Tone controls are not much use her. I am saving it for a rainy day to modify for guitar use.

I think it's a GEC amplifier similar to this one:-
http://www.youtube.com/watch?v=X0hqxSQ6Zss