Marantz variable resistor / volume pot

[snorbans]

I acquired a Marantz 1060. An early one, but it sounded good, weakness in one channel, nothing major, I cleaned the controls, contact cleaner into the volume pot, worked it back and forth, left it to dry, came back, a track had lifted. I assume it was so oxidised that the cleaning weakened it to the point it lifted but I read that the cement can be weakened by deoxit, living proof that Deoxit trumps Servisol, not always in a good way, I don't see anyway round replacing it.

So I need to replace a Marantz 1060 volume pot which is a common part between models of the time - RM0254021. I will look for an original but if the part could be replaced, and the looks turn out OK, that might be a way to go (the actual part being an expensive option after postage from the US where they mainly show up).

RM0254021 | Variable | 250KOhm | A (with loudness taps)

Glad of any advice.

If I was to replace, the best option seems to be

Alps Blue 250K stepped attenuator - RH2701 - The shaft is 2cm and the shaft width 6mm - does this work Ok with the existing knob? I see some information here as to the wiring. Any tips?

 

[rcs16]

Your problems are form fit function. finding a current production log taper volume pot of correct value with a loudness tap is near impossible. Second you have to match the shaft length/mounting and the portion for the knob. Probably the original is a knurled shaft, so you have to match that as well. not so easy.
show a link to that pot with a loudness tap, if it original great, good luck, people know these things are rare and charge accordingly.

 

[snorbans]

I think you are right, I should aim for the same for the sake of loudness function. More to investigate on this

I would love to hear if anyone has used other part numbers with adaption or without, Marantz 250k pots such as

RM02540220/3

The RM254023 has too long a shaft, it could be cut I guess but that is a risk and deprives Superscope owners of a part.

Terminals are 6 + 2, with the 2 for the loudness function. Both my 2245 and 1060 use the same RM0254021, its a pretty specific part though, there is a lug that fits into a panel on the front to prevent rotation.

I'll have to wait till one comes up, and use an Alps for now

 

[catrafter]

250K ohm dual volume controls with a loudness tap and a splined shaft are used on many Marantz models and come up all the time on the auction site.

Tom

 

[ConradH]

It does amaze me that nobody of known quality seems to be making a standard audio taper dual volume pot with a loudness tap. I've used the fake Alps blue ones you can get on eBay and they're quite variable, but by buying a few and selecting them you can often get by.

 

[snorbans]

Thanks Tom. I probably need to be patient and wait, but I have found a RM02540220, also 6+2, 'removed from a 2250 but will work in any 22xx series receiver that needs a 250 kOhm audio taper pot', since my 2245 has a RM0254021, that suggests they could be interchangeable. Shaft measurements look OK. Looking at photos, some have lugs to prevent rotation, some don't, lugs can be removed.

 

[snorbans]

The RM025040220 arrived and has the same shaft length as the one I'm replacing, the lugs need a little filing to allow the pot to fit without any gaps, I will post some pictures though this kind of thing takes me weeks to get round to. The resoldering will be daunting too, but it looks like it could work out.

I have 2 1060's, one has a serial number in excess of 533000, the other, 1042, its this old boy that's shown its age and succumbed to the contact cleaner.

Having removed the faulty one, and dissembled a little it was the track that had detached, I feel unlucky so hoping for some luck now to provide balance!