Hello All, sorry about the delay in updating you of the current repair of the amplifier! Here is what the Tech has stated...
Hi Mike
"An update and a few pics for you. I finished changing all the capacitors. Power was then applied in stages. The stabilisers made some strange noises and one part lit, but the other one was arcing due to the loose base having torn out the lead out wires. I installed a couple of NOS S130s and powered up again. The slow start relay was giving a few problems, so this has now been wired out. Although a good idea in theory, with valve rectifiers giving slow turn-on, it’s not really necessary.
The voltages were all checked but the valves seemed out of balance, and they are a mish-mash of types,/sizes so before going any further I treated it to NOS pairs of 6L6 and 6F6 for the different amplifier sections, as this is what I believe was originally intended
During testing, ocassional ‘arcing’ could be heard. I could not see an obvious reason for this but to me it sounded like AC problems. so it was powered down and all the voltage selectors and fuse holders were double-checked. It was while doing this I noticed the state of the wiring to the primary of the large mains transformer. This had been wired in rubber cabling for the voltage taps and all three were crumbling away ( see photos ) As I followed the leads back above chassis they literally fell apart in my hand.
As only the 240v wire is used, this was rewired with new cable, and the rest double heat-shrinked to keep then out of harms way. I was concerned that they may break off at the transformer whilst carrying this out, but the wire itself was good and strong, which is more than can be said for the insulation !!
Tthis seems to have fixed the problem. The whole chassis now powers up without fault and gets remarkably warm quite quickly. There is a hum response when tapping the input connections, and all the voltages look reasonable. The output stage balance was re-adjusted for the new valves and they are drawing a fair bit more current, which is to be expected as their emission is ‘as new ‘ To my surprise , the original paper in oil coupling caps seem fine with no leakage
The next stage will be the radio chassis. There is so little ‘gain’ on the main chassis ( inputs direct into phase splitter ) that it will need the preamp sections of the radio chassis to get any drive and see how many watts each amplifier actually outputs. There is still the question of the two missing valves. There already seem to be more than enough valves/stages on the radio chassis for this set up so it’s hard to fathom what two more valves are likely to be adding. All will be revealed soon, hopefully. "
So amplifier completed! So we need to find what the two missing valves or maybe they are not needed...
Will let you all know what happens next!
I have also been sorting out the turntable so will post a video for everyone once we have totally finished. I am so looking forward to the complete restoration!... keep you posted!!!!