Power supply upgrade. How do you know it is working?

I got hold of a Flatcap XS and wired it up right to my Nait XS Amp. I turned on the Flatcap XS first, then the Amp (don’t really get why the new external power supply isn’t now the ‘power source’ for the amp and you have to still turn both on).

It isn’t exactly obvious it is doing anything. E.g. a little LED saying ‘external power supply working’ on the Amp would be a nice touch. How can you tell? Obviously each device is on from the Naim glow, but that’s not proof they are working together.

I know ‘listening’ is one obvious answer. But I’m suspicious of subjective analysis and it hardly seems the scientific way to tell something is on and working as it should.

The Nait needs to be plugged in to the mains as the Flatcap only powers the preamp part, not the power amp. If you have removed the link plug and connected the Flatcap using two Snaic leads, a four pin and a five pin, and it is working, then the Flatcap is working, otherwise you’d have no sound.

It is only your ears that can determine if the addition of a Flatcap is worthwhile, and presumably you tried it before buying.

I don’t recall not hearing immediate improvement from any PS upgrade I’ve made.

I’m sorry to read of what seems like your disappointment, having connected it ‘right’ and switched on both FCXS and Nait XS. What is your source(s)?

I have, connecting a 555PSDR to a 272 - immediate and dramatic improvement.

Which begs the question as to why you made the upgrade.

1 Like

I think El Marcos double negative means he always did hear a SQ uplift from every Psu he added.

I’m sorry, I used a double negative. I’m confirming that every PS I’ve ever upgraded to has had an immediate and positive effect.

No, it’s me who should apologise. I’m a bit tired!! Time for bed I think.


This was my immediate reaction. I’ve been here a few times at a number of levels. The difference has never been subtle and always been positive. It appears that this upgrade isn’t working, either because the PS is not operating as intended, or it’s just not a good upgrade in this particular instance, which is unlikely but not impossible, I guess.

Did you audition it before you bought it?

I had very poor results when I put a flatcap xs on my nait xs2
To be honest…I never rated the flatcap in the slightest…
I tried a new cable that “linked” the audio without sending it through the flatcap and that was slightly better
Save your money and buy a supernait 2 or 3!!

I’ve never auditioned any Naim kit in my home. Listened to some at the dealer. And the first gen Supernait that I listened to at the dealer was the most disappointing kit I’ve owned. I was so happy to move that on.

No issues with any Naim power supplies not making a distinct and noticeable improvement on the equipment they were hooked up to. Flatcap, HC, HC2, XPS, SC2, all great.

Sorry. My post was to you but my question about auditioning should have gone to the OP.

To be honest, same here. HiCap, XPs2, 555PS, 555PS-DR yes. FC no.

Conversely, I loved what a Flatcap 2 did when used on a CD5. And adding it to a NAIT5 was also really worthwhile.

1 Like

CD5 was my first taste of the power of the power supply.

A Flatcap 2 worked really well with a 32-5 and CD3.5 too.

That was a seminal moment for me too. Never doubted the benefits of the PS since I added a FC2 to my old CD5.

Also the same here…was very dubious about the whole power supply shenanigans until my dealer put a flatcap on my cd5. Took about 20 seconds to make the decision that it was staying. Definitely the start of a slippery slope some 10 years or so ago! Don’t even get me started when he then convinced me to try a Powerline on the CD5 as well…

I can’t think of any Naim component I’ve used that didn’t have a PSU powering it. Even the stageline used a HiCap2 to boost it. Naim are very canny marketeers! :wink: