Naim Power Switch

[Suffolk Tony]

Hi folks,
In pursuit of continuing quest to save the Planet, I've recently taken to switching my amps off regularly, rather than just leaving them on permanently. However, the latching action doesn't always engage & I have to fiddle around before the blasted things will switch on properly. I've sprayed with switch cleaner, which seemed to help, but now I'm contemplating replacing these switches. I'm wondering what the spec. is, and what might be the best make to use? I'm sure my trusty Naim dealer could help, but being a poor old pensioner I'd rather not have to pay Naim-type prices.

All help & advice gratefully received.

 

[coupe-sport]

Is this on your NAP500s Tony ?

 

[Suffolk Tony]

Yes.

 

[hp1]

For the 500ps its the same alps made switch as used in all the full width naim kit since the olive range started , I think its a t3p.

 

[Suffolk Tony]

Thanks hp1. I've done a bit of a search on that part no., but can't seem to find anything. I'm wondering if i's worth replacing these switches - it's a fairly minor inconvenience. Maybe a tadge more switch cleaner & work them off & on a few times? No reason for them to be worn out, so I'm wondering if this can be caused by lack of use.

 

[chrisn]

RVFM PT-M3BL from Rapidonline is the perfect replacement from the fit point of view and I have fitted a couple to olive kit. They are 4 Amp as against 5 Amp for the originals which has always bothered me a bit, but 4 Amps is still less than the fuse specification.
Also I have never managed to get a sticking Naim switch to unstick reliably no matter how much you fiddle.
Correction - I meant to say the 4 Amp switch comfortably exceeds the fuse specification

 

[Suffolk Tony]

Wizard! Many thanks Chris, on order.

 

[davidsrsb]

RVFM PT-M3BL from Rapidonline is the perfect replacement from the fit point of view and I have fitted a couple to olive kit. They are 4 Amp as against 5 Amp for the originals which has always bothered me a bit, but 4 Amps is still less than the fuse specification..

The fuse should have the lower rating. Now we know why Naim said to leave the amplifier switched on.

 

[hp1]

The alps ones are hard to get but worth it over the copy one from rapid, i dont think it will last too long switching a nap 500 trafo .

I think a good naim dealer would get you one from the factory,probably money well spent if you factor in fitting it.

 

[Loz828]

I am currently looking at an Olive XPS, dont know if the switch is the same as a NAP500 but an ealier poster said the Olive full width were the same, maybe this helps.
The switch is made by ALPS, and the markings on it say SDS3P 250V/5A - I can't post pics here but could PM you one (I think) if you want me to.

 

[Suffolk Tony]

Thanks for your help Loz. I've found it on eBay from Japan, but think I'll try the one I've already ordered first.

 

[Loz828]

Thanks for your help Loz. I've found it on eBay from Japan, but think I'll try the one I've already ordered first.

As someone said previously, if you ordered the one from Rapid it's only rated at 4A, it's up to you but the 500 toroid must have quite a large inrush so you might be pushing it. Also on my power switch there are 5 wires (because it's 120V) which makes the soldering quite tight and not something I would want to have to do over and over again, Naim tend to cut and dress wiring to exact legnths so the opportunity to cut/strip/resolder can be limited without making your very pricy investment look a bit messy, and that will make you sad
Also it looks like there are PCB pins on one side of the switch (on both the ALPS and Rapid) which Naim simply cut off close to the body.

 

[chrisn]

I corrected my earlier post as I meant to say the 4 Amp switch exceeded the fuse specification in the items where I have fitted one.
The Nap 500 has a T3.15AL I think so someone may be able to advise you if it is OK.

 

[Suffolk Tony]

Yes, they're definitely fitted with 3.15A slow-blow fuses - just checked.

 

[Suffolk Tony]

As someone said previously, if you ordered the one from Rapid it's only rated at 4A, it's up to you but the 500 toroid must have quite a large inrush so you might be pushing it. Also on my power switch there are 5 wires (because it's 120V) which makes the soldering quite tight and not something I would want to have to do over and over again, Naim tend to cut and dress wiring to exact legnths so the opportunity to cut/strip/resolder can be limited without making your very pricy investment look a bit messy, and that will make you sad
Also it looks like there are PCB pins on one side of the switch (on both the ALPS and Rapid) which Naim simply cut off close to the body.

Once the switches I've ordered arrive, I'll have a peek inside the PS and see exactly how best to fit one neatly. I like to think I'm a pretty tidy solderer, but obviously if I think I can't complete the task without making a pig's ear out of it then I shall desist, pop it back on the shelf and put up with the minor inconvenience. They'll probably outlast me the way they are anyway...

 

[peterm]

I believe LesW found a source of black rocker switches with exactly the right dimensions to fit the front panel cut out on Naim amplifiers that use the push button switch. I have one in one of my amplifiers (I bought it like that).
The switches Naim used are notoriously fragile, both mechanically and electrically, over time.
I seem to remember Les saying that with the more robust rocker switch his modded amplifiers should be good for 30 years (and Les recommends switching them off when not in use).

 

[Suffolk Tony]

I believe LesW found a source of black rocker switches with exactly the right dimensions to fit the front panel cut out on Naim amplifiers that use the push button switch. I have one in one of my amplifiers (I bought it like that).
The switches Naim used are notoriously fragile, both mechanically and electrically, over time.
I seem to remember Les saying that with the more robust rocker switch his modded amplifiers should be good for 30 years (and Les recommends switching them off when not in use).

Considering the minimal use these switches have been subject to, the fact they're Alps, and considering the bulletproof nature of the rest of my Naim kit, it's pretty disappointing that they're so flaky. I'll maybe give Les a call if these other switches prove not to be up to scratch (although reading some reviews they do seem to be very good).

 

[Loz828]

Yes, they're definitely fitted with 3.15A slow-blow fuses - just checked.

My NAP250s are fitted with 6.3A fuses as they are supposed to be, because they're running on 120V, and you frequently see electrical parts inside units rated well below its minimum protection, so I wouldn't worry about that even if it was an issue for you - which it isn't. But even a 4A switch behind a 6A fuse - meh who cares, bad design maybe and by no means poo poo the need for proper fusing/circuit protection, but if the switch catches fire it's more likely to be arcing than an overcurrent which conveniently sits between the max switch rating and fuse blow rating - unlikely, and even if it did its inside a whopping aluminium case - you're more likely to die in a horrific gas explosion.
I was more concerned about the durability of a "clone" switch with a 4A rating as you give that 30A (wild guess) inrush every time you turn it on / off which you seem to want to do. I say "forget the planet - save the Naim".

 

[Pete MB&D]

My 135 clones burnt out 16a rocker switches, when I took them apart the contacts had vaporised just leaving a ring of metal.
I replace them and leave them on all the time.

Pete

 

[hp1]

Although its impossible to see in side these switches I do try to keep the contacts clear by unplugging the mains supply and operating the switch about 30 times on and off periodically , I use about 30 of them and have had no problems including 3x500s .