Pioneer SA 506 front cover potentiometer spacer nut replacement? [help] - Page 1
Forum section: electronics / repair

author: ESXi
author_rank: Regular Contributor
timestamp: October 08, 2018, 01:38:54 pm
content: 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 shortHere'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 ShaftAny 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?

author: coromonadalix
author_rank: Super Contributor
timestamp: October 09, 2018, 08:47:47 pm
content: Never saw this dual stage nut before ? On all the tunners / amps i've repaired it looked like the second picture

author: ESXi
author_rank: Regular Contributor
timestamp: October 12, 2018, 01:25:34 pm
content: Quote from: coromonadalix on October 09, 2018, 08:47:47 pmSeen 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..Quote from: coromonadalix on October 09, 2018, 08:47:47 pmIf 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.

author: coromonadalix
author_rank: Super Contributor
timestamp: October 12, 2018, 10:35:54 pm
content: well if you search "potentiometer nuts" you'll have some links and imagesYou have to knows the inside and outside diametersyou have 1/4 shaftsyou have 3/8 shaftsBourns use 9mm shafts nuts in some models ??or in metric Ex:Thread Size: M7, Hex Size: 10mmInner diameter 7mmOuter diameter 10mmEbay link:https://www.ebay.com/itm/20-Set-Metal-Nuts-Flat-Washer-for-1-4-Potentiometer-/290572560386https://www.ebay.com/itm/10-Set-Metal-Nuts-Flat-Washer-for-1-4-Potentiometer-Pots/300562740640

author: coromonadalix
author_rank: Super Contributor
timestamp: October 12, 2018, 10:38:28 pm
content: you have this one an 3/8 diam sloted nuthttp://shop.frontpanels.de/product_info.php?info=p50_special-3-8--potentiometer-nut.htmlIf you back one page you find some strange shaft adaptershttp://shop.frontpanels.de/index.php?cat=c20_potentiometer-shaft-adapters-potentiometer-shaft-adapters.html

author: ESXi
author_rank: Regular Contributor
timestamp: October 13, 2018, 09:45:44 am
content: Quote from: coromonadalix on October 12, 2018, 10:38:28 pmNone 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:

author: coromonadalix
author_rank: Super Contributor
timestamp: October 13, 2018, 12:05:03 pm
content: 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 anymoreOr 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.

author: ESXi
author_rank: Regular Contributor
timestamp: October 15, 2018, 09:10:37 am
content: Quote from: coromonadalix on October 13, 2018, 12:05:03 pmEh 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.Quote from: coromonadalix on October 13, 2018, 12:05:03 pmI 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.

author: ESXi
author_rank: Regular Contributor
timestamp: October 15, 2018, 09:59:00 am
content: I think I just found a solution for this problemhttps://www.ebay.com/itm/Volume-Aluminum-260mm-potentiometer-extension-shaft-HIFI-DIY-connecting-long-rod/163008546001I 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.

author: coromonadalix
author_rank: Super Contributor
timestamp: October 15, 2018, 10:35:15 am
content: Very nice find, i have bookmarked it and saved the picture(s), you never know lollLucky for you