Rewiring handmade 1960's/70's record player.

[XsamX1987]

Oh no don't get me wrong I want to learn I'm not going to just pull the thing apart and slap it back together and hope for the best

I mean I've restored an old motherboard before I had to learn how to solder small items/ voltage /removing dead caps and replacing with new ones hunting down parts

I repaired my TV/dishwasher/tumble dryer/washing machine

[jay_oldstuff]

Id guessed from your avitar you may be in to vintage computers and with what you've said you've worked on in the previous post it doesnt look like mains voltages bother you, so id say with a little guidence this project should be viable for you.

id split it into two parts, first get the deck wired up properly should be fairly easy. then look at the amplifier. pull it out of the case so we can take a look and advise you. shame your not local or id pop round and give some pointers.

[dave walsh]

That extra info is really invaluable Xsam. New Forum members are always wanted but the "retro" boom has sometimes produced a "gung ho" attitude that can be worrying. We don't want any casualties but now you sound as safe anyone can be. Good luck with which ever route you take

Dave

[camtechman]

At least, one thing the OP has is enthusiasm and, with continued determination on his side, and along the way, a few 240v shocks (and who amongst us ever let that dent our drive and stop us)

It reminds me of, when I was a youthful 13 years of age how exciting it was to dive into a knackered E.A.R. record player and, even now at 70 years of age this October and despite 2 heart attacks, aching joints and failing eyesight, I still get a buzz (sometimes literally) repairing/restoring vintage equipment.

All power to you XsamX1987

[Techman]

I think that as long as none of the major components such as the mains and output transformers are faulty, then you could soon have this thing up and running in no time.

It worked as it was with the wiring as it was twenty years ago, so there's no reason why it shouldn't be made to work as it is now. Once you know that it's capable of working, you can then take time out to re-wire and re-build it in a better and safer manner. If either of the transformers are faulty for any reason, then the unit is basically scrap and not worth spending time on.

My advice would be before disconnecting any of the wiring, carefully unbolt the amplifier chassis from the case and take a good clear photo of the underside of the chassis showing all the components so that advice can be given with regards to their state and type. Be careful not to break any of the glass valves when you turn the amplifier chassis over. With your multimeter set on the lowest ohms range, check the resistance across the speaker terminals. This will be a very low reading as you'll be reading the DC resistance of both the speaker and the secondary of the output transformer that it's connected to. The VERY important part of this test is that you should hear a slight crackle from the speaker as you connect the probes, thus pointing to it being in working order. Report the ohms reading you get and whether you heard a 'crackle' sound as you connected the probes from your meter. Obviously all this is done without any power applied to the unit. This should take you just a few minutes to do.

The next test is to identify the primary winding of the output transformer - easy as it'll be the other connections that don't have the speaker connected to them, and measure the resistance across these connections - it should be a 'higher' resistance. Report what you find.

What I would do next is to identify the rectifier valve and remove it. I would then apply mains (3 amp fuse in plug) and see if the remaining valve heaters warm up and glow. Removing the rectifier removes the HT supply from the circuit, thus preventing any possible damage due to a fault. With it still powered up I would then check for the un-rectified AC voltage from the HT secondary of the mains transformer. Be VERY careful with this measurement as this is a HIGH voltage from a low impedance source and it can KILL you if you touch it with a finger - ask for advice if in any doubt!

Having done these tests you'll know if the transformers are ok and unit will then be capable of working once other (much cheaper) faulty components have been replaced.

[XsamX1987]

Thanks every one a lot of kind and encouraging caring words

I will get back to you all soon with a Update