Alpha Pot mods

[David Schwab]

I have to try that Stabilant out. I still have that sample.

[NateS]

OK - finally got time to destroy a single (unganged) Alpha. The Shaft is ~6.5mm, then it's turned down maybe 5mm to pass through the collar/yoke, then flats milled on either side so that it's about 2mm thick - this passes through the plastic disc, (which it turns out is rather brittle as plastics go), then this bar is peened to make the little wings that hold the plastic backplate disc in place.

I don't see much how the shaft can be saved, but if you wanted to go through the trouble to turn another one (I do have a mini-lathe but haven't retrieved it from storage since moving) - you could make one which was pinned instead of deformed to retain the plastic backplate. Hardly worth it though. I think I'll try again at finding a bottom wafer pot (like the ones Tayda sells - thanks for the info.) As for the law bending resistor - I considered it, but it means that my magnetic pickups (which are single coils - GFS Mean 90's) - would have a pretty substantial load on them at full volume (50k or so), which I'd expect to significantly change the tone.

[NateS]

Ah but it should be possible to more or less straighten out a log tapered pot using the reverse log taper resistor AND wiring the pot backwards.

[J M Fahey]

One of the wonders of living in a Country with a good but small Industry is that I have unthinkable direct access to Factories.
I can have dual pots made, any shaft they have, any mix and match tapers,in 100 lots, for little over the regular price.
They use the "external wafer" type, so itīs easy for them mount any combination.
Although they donīt mention it on their catalog, Iīve had dual reverse log pots for Parametric EQs and active crossovers made simply by having dual log ones mounted with the wafers exchanged.
Try that with Alpha or any other "big" Factory.
:::: Vantronic S.A ::::

PS: they claim to have a minimum 300 unit minimum order, but they always made 100 lots for me.

[David Schwab]

One of the wonders of living in a Country with a good but small Industry is that I have unthinkable direct access to Factories.
I can have dual pots made, any shaft they have, any mix and match tapers,in 100 lots, for little over the regular price.
They use the "external wafer" type, so itīs easy for them mount any combination.
Although they donīt mention it on their catalog, Iīve had dual reverse log pots for Parametric EQs and active crossovers made simply by having dual log ones mounted with the wafers exchanged.
Try that with Alpha or any other "big" Factory.
:::: Vantronic S.A ::::

PS: they claim to have a minimum 300 unit minimum order, but they always made 100 lots for me.

Cool! Do they make concentric pots?

[jrfrond]

One of the wonders of living in a Country with a good but small Industry is that I have unthinkable direct access to Factories.
I can have dual pots made, any shaft they have, any mix and match tapers,in 100 lots, for little over the regular price.
They use the "external wafer" type, so itīs easy for them mount any combination.
Although they donīt mention it on their catalog, Iīve had dual reverse log pots for Parametric EQs and active crossovers made simply by having dual log ones mounted with the wafers exchanged.
Try that with Alpha or any other "big" Factory.
:::: Vantronic S.A ::::

PS: they claim to have a minimum 300 unit minimum order, but they always made 100 lots for me.

I might have to consider them for an upcoming project that needs a custom dual pot of 1MA/10KL.

[jrfrond]

Mark, if you are using it straight, you are wasting it. You need to dilute it 4:1 with pure (water-fee 99%) isopropyl alcohol. When you do this, you can flow it in with a needle applicator and also use it to flow into recalcitrant tact switches and the like. The stuff is often lifesaving, but it's pricey and you need to use it properly. These are the applicators we use here: GC Electronics Chemical Injector | 8383 | GC Electronics

Stabilant is a conductivity restorer, NOT a cleaner, though the alcohol does do a bit of cleaning as well, leaving behind the Stabilant film. It's used by MANY big electronic companies, aerospace, military, etc. Back in the 80's, it was called "Tweek", and marketed to the audiofool industry, but they've graduated to smarter and more knowledgeable clientele. If you call the company, they will tell you anything you want to know, and are very nice people. I'm totally sold on the stuff.

I have a little applicator on my bench with my "secret formula": Stabilant 22A diluted, with a few drops of DeOxIt 100 added to it. It's my miracle cure, especially for mixers with bad switches. Instead of taking them apart, we pull the caps and run the stuff down into the switch. Works about 90% of the time.

[J M Fahey]

@ David Schwab
They did, a long time ago, for car radios (Volume and Tone; the "other knob" on the opposite end was Tuning); donīt know whether they still have the dies and hardware.
We are talking 30/40 years ago.
Will ask informally, maybe some old employee remembers something.
*If* possible, it would definitely not mean just mounting 100 off from regular parts they already have in stock but going a production run, way higher quantities.

@ JRFrond
1MA+10KLin sounds reasonable, a friend of mine had something similar built, Iīll ask him.

[NateS]

Tayda was actually pretty quick on shipping. And the swap was trivial with the style Mark first linked. As in I think I can hold my breath for the length of time it took to swap them.