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Anyone Know of a Long Shaft Blend Pot?


Obrienp
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Hoping to tap into the collective knowledge of the forum here. I have a custom made P/J with controls mounted through body. It currently has VVT controls but I always wanted volume/blend/tone. At the time of the build, the luthier was unable to source a long shaft blend pot and not wanting to delay things even more, I compromised on CTS long shaft pots in VVT.
 

I looked around for ages trying to find a blend pot that might do the job. There seemed to be a shortage of this kind of stuff in the UK during lockdown. I got hold of an Alpha blend pot but it just didn’t quite make it through the body far enough to get the nut to engage with the thread. The luthier offered to take some wood out of the control cavity to make the top thinner but at my risk and I decided I didn’t want to risk weakening it.

 

Now that supplies are coming back into the the UK, I decided to renew my search but I haven’t been able to find a suitable long shaft blend pot with the dealers I know of. Does anybody out there know if a long shaft blend pot is made and where I can get hold of it in the UK?

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10 hours ago, paul_5 said:

Have you tried North West guitars? They’ve got loads of this kind of stuff.

 

https://www.northwestguitars.co.uk/blend-pot-250k-split-shaft/

 

Hi. Thanks for the suggestion. I’ve tried an Alpha and unfortunately the shaft isn’t long enough for the nut to bite on the thread. None of the usual suspects list a long shaft 250k blend pot.

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Would it feasible to add a small section to the top of the pot you have by cutting the top off of another pot and attaching it to the Alpha (epoxy, drill and screw, whatever)? A bit Heath Robinson, but a potential solution if solid enough.

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1 hour ago, ezbass said:

Would it feasible to add a small section to the top of the pot you have by cutting the top off of another pot and attaching it to the Alpha (epoxy, drill and screw, whatever)? A bit Heath Robinson, but a potential solution if solid enough.

I did wonder about that.  I might give that a try if all else fails. I would need to sleeve the thread and extend it, which would mean having a larger dimension retaining nut. Knowing my luck it would come off mid-gig with the blend 100% bridge pickup!

Edited by Obrienp
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@Obrienp Never seen any blend pots with long mounting thread, (not shaft - that's the bit the knob goes on). The obvious answer is to remove a smidgen of wood inside the cavity where the pot sits, carefully 😉 so more thread sticks through, if you're OK with woodwork handtools, if not see a luthier.

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9 minutes ago, KiOgon said:

@Obrienp Never seen any blend pots with long mounting thread, (not shaft - that's the bit the knob goes on). The obvious answer is to remove a smidgen of wood inside the cavity where the pot sits, carefully 😉 so more thread sticks through, if you're OK with woodwork handtools, if not see a luthier.

The luthier that built it did offer to do this but at my risk. Also the whole thing is shielded to blazes, so it will mean destroying a lot of that in the process and redoing it. However, I think you are right: it is my only option if I want a blend pot. My bad for opting for through body controls. I just assumed there would be long threaded blend pots like there are for standard pots. They do seem to refer to these as long shaft in the catalogues but yes, it is really the depth of threaded portion that is important.

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I can't imagine why a luthier wouldn't 'just do it' without any talk of 'at your risk', if he's not proficient I'd seek another luthier. Re-doing a bit of copper foil or shielding paint ain't exactly difficult either, IMO 😇

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4 minutes ago, KiOgon said:

I can't imagine why a luthier wouldn't 'just do it' without any talk of 'at your risk', if he's not proficient I'd seek another luthier. Re-doing a bit of copper foil or shielding paint ain't exactly difficult either, IMO 😇

I’ll probably do it myself anyway. I think risk was minimal but I wanted a cheap approach rather than his more thorough but more costly method. No doubts about his ability. He is extremely proficient but also extremely busy. I guess the one follows the other in that trade but it does mean having to wait until he has a slot.
 

 I’m just being lazy regarding the shielding. It took a while to get it as quiet as it is now and I don’t want to mess that up.

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Hi Pat, might be sticking my neck out a bit but I have a similar problem and my be able to 3d print an adapter for short to long shaft to make it to a through body mounted pot. I could only find knurled split shaft 1M short pots  for the active pickup project I'm working on at the mo.  It may be possible to swap bits out from simiar manufacturer to create your own custom pot, but it can get a bit spendy though. I'm still early days with the adapter, I'm not sure if there is the clearance to make it work without drilling or aestheticly displeasing gaps but I'll keep you posted if I find a solution.

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8 hours ago, Hacksawbob said:

Hi Pat, might be sticking my neck out a bit but I have a similar problem and my be able to 3d print an adapter for short to long shaft to make it to a through body mounted pot. I could only find knurled split shaft 1M short pots  for the active pickup project I'm working on at the mo.  It may be possible to swap bits out from simiar manufacturer to create your own custom pot, but it can get a bit spendy though. I'm still early days with the adapter, I'm not sure if there is the clearance to make it work without drilling or aestheticly displeasing gaps but I'll keep you posted if I find a solution.

Thanks Mate! That sounds really interesting. Yes, I was wondering about having to enlarge the hole if I sleeved the threaded collar. I really don’t want to have to do that.
 

I have put the project to one side for the while as it is my main gigging bass and I have a few coming up. Once the Acinonyx, that I ordered months ago, finally arrives, I will have an alternative solid bass to use and I will be able to crack on with it. I was kind of resigned to having the control cavity routed out a bit more. It’s got to go back to the luthier anyway because it has some fret sprout. Apparently the woods available to luthiers these days are not what they used to be: not seasoned enough and consequently subject to shrinkage but he thought this was one of the better blanks. Anyway, if there is away of avoiding routing it would be great.

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8 hours ago, Hacksawbob said:

Thanks. That looks promising.

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11 hours ago, Obrienp said:

I was just going to place an order until I found out the shipping cost: £12. About 5 times the cost of the pot.

https://www.ebay.co.uk/itm/322519387326?epid=885878986&hash=item4b17a74cbe:g:4hoAAOSwxvBZofei

 

still taking the fosters a bit but works out cheaper. go off the mfr part number on the mouser site and see if you can find a UK supplier.

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21 hours ago, Obrienp said:

I was just going to place an order until I found out the shipping cost: £12. About 5 times the cost of the pot.

They have the B2 6mm plain shaft version too.


The shipping is pricy, but it’s a specialist part from a supplier that isn’t set up for small orders, so understandable.

 

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RS Components have the Bourn Pots listed above with more reasonable shipping:

 

Bourns 500kΩ Rotary Potentiometer 2-Gang Panel Mount, PDB182-GTRB1-504MN

https://uk.rs-online.com/web/p/potentiometers/7703071

£2.48 each

 

Bourns 250kΩ Rotary Potentiometer 2-Gang Panel Mount, PDB182-GTRB1-254MN

https://uk.rs-online.com/web/p/potentiometers/7703062

£2.84 each

 

Next day shipping £5 or free for orders over £30.

 

 

 

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1 hour ago, Smanth said:

RS Components have the Bourn Pots listed above with more reasonable shipping:

 

Bourns 500kΩ Rotary Potentiometer 2-Gang Panel Mount, PDB182-GTRB1-504MN

https://uk.rs-online.com/web/p/potentiometers/7703071

£2.48 each

 

Bourns 250kΩ Rotary Potentiometer 2-Gang Panel Mount, PDB182-GTRB1-254MN

https://uk.rs-online.com/web/p/potentiometers/7703062

£2.84 each

 

Next day shipping £5 or free for orders over £30.

 

 

 

Thanks for that. I’ll give them a go.👍

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Noll sells Alpha blend pots in 250K with 10mm long bushes, they  are A/C taper though, not M/N: https://www.noll-electronic.de/potentiometer/

 

Omeg will happily make you some with 12mm bushes as well but you may need to buy ten.

 

A few of us who play in my long open source preamp thread at that other place have also worked up various bush adapters. This guy did the nicest job IMO: https://www.talkbass.com/threads/the-passinwind-open-source-preamp.1259692/page-49#post-25906207

 

In my usual fashion I just went to my local hardware store, bought a few lamp fixtures and some superglue, and came up with this for some Tayda/Alpha dual pots I used in a DIY filter preamp build:  

 

TaydaPots_adapted.JPG.3b213b29fd3a773c814d601ba6cba1b9.JPG

 

There are still the stock 7mm dia. bushes underneath the threaded lamp rod, which is 3/8" with a slightly coarser thread than is standard for potentiometers. My hardware store sells a few different style nuts that worked fine though. I had these in my bass while waiting for the Omeg ones I bought to come in and they held up fine.

 

And finally, V/V/T works better than a blend pot in a way that matters a great deal to some of us and not at all to others. And vice versa...no need to rehash that here.😉

Edited by Passinwind
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20 minutes ago, John Cribbin said:

Switchcraft used to, or maybe still do, an extended version of these for when a body was to thick for the one shown to be fitted. Maybe there's an equivalent fitting for pots? IMG_20220517_155313916.thumb.jpg.3466b40b465f0c5b35caa2965bcb7ba0.jpg

From the thread I linked to:

 

1530409094_PotBushings.jpeg.9fca0e5be8c7e8a141e169639aef38bc.jpeg

 

 

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