Pioneer SA 506 front cover potentiometer spacer nut replacement? [help]

[ESXi]

Hi there,

So I got my hands on this cool old amp and I'm repairing it, but I found out the aluminium front cover was lose because of a broken nut because the dingo dongo who tossed out the amp literally tossed it.

I am also looking for a suitable potentiometer for the bass filter because it was broken off.
After some searching I found a really nice replacement but I checked the measurement and I think the legs are too short

Here's the nut I am talking about for the front cover (including my shitty measurements )

Forgot to mention the inside dimension of the nut, this is 7mm. Actually the same as the ALPS RK16 100KAX2 I found on ebay.

Talking about this one:
Japan ALPS RK16 100KAX2 LOG Stereo Volume Potentiometer Dual 100K Knurled Shaft

Any ideas on how to get hold on a nut for the front case, and what about the potentiometer, is there a better alternative or should I just extend the legs and live with it or wait for NOS to popup on ebay?

[coromonadalix]

Never saw this dual stage nut before ?   On all the tunners / amps  i've repaired it looked like the second picture

[ESXi]

Never saw this dual stage nut before ?

Seen it many times before, but different ones, and to be mentioned. Not on all amps. Most more modern amps don't use this kind of dual stage nut anymore because the fronts are mode of plastic..

On all the tunners / amps  i've repaired it looked like the second picture

If its this common, do you mind sharing a ebay link or whatever link to a website where I can buy one that is to spec or at least fits on my amp?
Because I can't find it. Thanks mate.
 

[coromonadalix]

well if you search "potentiometer nuts"  you'll have some links and images


You have to knows the inside and outside diameters

you have 1/4 shafts
you have 3/8 shafts
Bourns use 9mm shafts nuts in some models ??

or  in metric Ex:
Thread Size: M7, Hex Size: 10mm
Inner diameter 7mm
Outer diameter 10mm

Ebay link:
https://www.ebay.com/itm/20-Set-Metal-Nuts-Flat-Washer-for-1-4-Potentiometer-/290572560386
https://www.ebay.com/itm/10-Set-Metal-Nuts-Flat-Washer-for-1-4-Potentiometer-Pots/300562740640

[coromonadalix]

you have this one    an 3/8 diam sloted nut
http://shop.frontpanels.de/product_info.php?info=p50_special-3-8--potentiometer-nut.html



If you back one page  you find some strange shaft adapters

http://shop.frontpanels.de/index.php?cat=c20_potentiometer-shaft-adapters-potentiometer-shaft-adapters.html

[ESXi]

you have this one    an 3/8 diam sloted nut
http://shop.frontpanels.de/product_info.php?info=p50_special-3-8--potentiometer-nut.html



If you back one page  you find some strange shaft adapters

http://shop.frontpanels.de/index.php?cat=c20_potentiometer-shaft-adapters-potentiometer-shaft-adapters.html

None of the nuts do even come close to what I am talking about. Did you even open up my dimensions and schematic picture? I have the lock nuts but not the nut that goes over the potmeter for the front aluminum cover. The nut that goes over that nut has another size (see picture). I really don't know what to search for. My suspicion is that the part is custom made for this amplifier. But I am not sure. Haven't found anything even close while searching google images for a full hour.

Picture:

[coromonadalix]

Eh  I was just giving some help and suggestions,  theses links are what we found nowadays.

Since you have dual staged special nuts, make new machined ones if Pioneer does'nt have them anymore   Or if youre lucky find an donnor ??

In 30 years of electronics, i personally never saw in Canada this nut type. 

Some of your   Pioneer sa506 are on ebay right now, starts at 130$ minus shipping ........   surely you can find a machinist to make a few nuts ?

Good luck.

[ESXi]

Eh  I was just giving some help and suggestions,  theses links are what we found nowadays.

Eh alright well don't get me wrong. I was a little bit frustrated because I can't find anything close, but thanks a lot for the effort helping me.

Since you have dual staged special nuts, make new machined ones if Pioneer does'nt have them anymore   Or if youre lucky find an donnor ??

In 30 years of electronics, i personally never saw in Canada this nut type. 

Some of your   Pioneer sa506 are on ebay right now, starts at 130$ minus shipping ........   surely you can find a machinist to make a few nuts ?

Good luck.

I have seen the amps, But don't want to buy a "new"/doner one for this. It used to be a cheap hobby project but already spend like 60 euro on the amp..
Know a machinist that can CNC a part for me but he told me it's gonna be difficult because it's so small and the screw thread on the outside is going to be difficult to do.

[ESXi]

I think I just found a solution for this problem   
https://www.ebay.com/itm/Volume-Aluminum-260mm-potentiometer-extension-shaft-HIFI-DIY-connecting-long-rod/163008546001

I only have to tap a thread on the inside where the hex nut is (bottom).


Expensive for this nut only, but it's worth the try.. The part is not completely spot on(measurement wise) but I will add a spacer disk between it.

[coromonadalix]

Very nice find,  i have bookmarked it and saved the picture(s), you never know  loll

Lucky for you