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Techman · 19th Jun 2016, 10:36 pm

There will be the usual coupling capacitors to replace and any cathode decoupling small electrolytics. The main HT smoothing electrolytics may well be ok. You could try reforming them or run the thing up via a lamp limiter and check voltages etc. to see what's happening.

Speaking for myself, I would just make a few static checks, and then with a voltmeter connected to the HT line I would give it full mains for just long enough to see the rectifier start to conduct and then cut the power as the HT got to about 30 - 50 volts. I would repeat this a few times, gradually letting the HT voltage get a bit higher each time while checking for any slight warming of the capacitor cans and any other smoke, sparks etc. that shouldn't be there - but that's just me!

If you're going to do any major work on the amp chassis, I would advise removing those output valves and packing them away in soft wrapping somewhere, as it'll be no good asking for replacements for those in the 'wanted' section if you end up busting them - and it doesn't matter that they have the Osram label.

19th Jun 2016, 10:36 pm	#100
Techman Dekatron Join Date: Nov 2009 Location: Lincolnshire, UK. Posts: 5,000	Re: Restore a Beau Decca There will be the usual coupling capacitors to replace and any cathode decoupling small electrolytics. The main HT smoothing electrolytics may well be ok. You could try reforming them or run the thing up via a lamp limiter and check voltages etc. to see what's happening. Speaking for myself, I would just make a few static checks, and then with a voltmeter connected to the HT line I would give it full mains for just long enough to see the rectifier start to conduct and then cut the power as the HT got to about 30 - 50 volts. I would repeat this a few times, gradually letting the HT voltage get a bit higher each time while checking for any slight warming of the capacitor cans and any other smoke, sparks etc. that shouldn't be there - but that's just me! If you're going to do any major work on the amp chassis, I would advise removing those output valves and packing them away in soft wrapping somewhere, as it'll be no good asking for replacements for those in the 'wanted' section if you end up busting them - and it doesn't matter that they have the Osram label.