Debugging Supernait 3 Midrange Distortion

What’s the crossover point of the midrange/tweeter horn to the large bass driver ?

400 Hz

I’m no expert. But, reading through articles in some years - there is often mention about crossover distortion within an amplifier itself - how it deals with the transition from A to B. I have read in the past that Naim amps have relatively little to no crossover distortion.
Although some golden ears have switched to purely class A/tube because of running very efficient speakers that shines a spotlight on that distortion that is there nonetheless.

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Here is the interesting development of continuing to work this morning.

At first I took out the Rivals and replaced them with my home theater Klipsch RF-7IIIs. There was still the noise though not as prominent, and the sonic signature of the RF-7IIIs was pretty significant (much more forward highs).

Then I brought the Rivals back in and used the subwoofer out of the Supernait 3 to go into my Anthem MCA 325 home theater amp. So bypassing the amp section of the SN3.

The noise was still there and clearly the Anthem is an inferior amp so it sounded worse in general.

FINALLY I went RCA out from the NDX2 into my Luxman CL40 tube preamp, which then went into the Anthem MCA 325 - bypassing the Supernait 3 entirely.

Lo and behold, aside from the sonic differences of the mismatched Luxman/Anthem gear, the noise is gone. In fact, going back to “River in the Rain” and “Everybody Hurts” - where there was noise and fuzz in the mix before suddenly I hear a tuba in River in the Rain swelling with the strings and the guitar is clear and strong. The washed reverb guitars in the bridge of “Everybody Hurts” sounds like a cascading clean wash of guitar, and suddenly I am hearing pizzicato strings in the mix as well.

Keep in mind this is through a 40 year old vintage preamp and home theater amp, versus the Supernait 3.

This is good news bad news, which means my hearing is not shot but also it seems like the preamp section of the Supernait 3 is the culprit. So I am not sure if this is a factor of all SN3 preamps but it is just more audible in my highly sensitive speakers, or if there is a defect in my Supernait 3.

At the least it seems like I’ve honed in on the issue.

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Another approach might be to try to borrow from someone another capable power amplifier and take a feed from the preamp output of the SN3. It doesn’t have to be a Naim power amplifier. For example I am using a Nova as streamer/preamp into an old Quad 606 amplifier to drive the Naim SL2s in my second system and that sounds better to me than the Nova driving the SL2s direct.

Edit: I just read your latest post. I think you should get your SN3 checked out because I think it may have a fault.

Best

David

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It could be David I hate to go through all of this with my dealer and Naim but I don’t know that there is a choice.

One final question in all of this - is the HiCap DR the power for the preamp section of the SN3?

If so, is it possible the HCDR could be contributing to the noise of the SN3 preamp section? Reason I ask is that the HCDR is the one USED piece of gear I have in my system, and potentially there could be a fault with that power supply.

I can take it out of course but my Naim boxes are in storage across town which is where the cap is for the HiCap section on back of the SN3.

Yes, you should try removing the HiCap. How old is it…?

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Thinking back to my Nait 5 experience, I’d have had a cheap and very light CD player I’d bought from Richer Sounds, an budget hifi outfit. That would have had a SMPS in it so may have been the source of my problem with that amp. It doesn’t explain the supernait demo but I don’t know the setup details for that, the dealer was highly experienced and the supernait was his recommendation.
Anyway looking at the cabling pictures I see several items that would use SMPS and 3 mains powered Naim boxes. What are the details of where they’re plugged in? I see what I take to be a block on the floor but what’s plugged in where isn’t clear.
You could also try the hicap below the XPS in the hope it will make the Burndy hang clear of the floor or at least relieve stress on it.

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I think the answer is yes too, like IanRobertM. Maybe your dealer could loan by post a cap so you can try the SN3 without the HCDR, or even sell you one. Anyway definitely you need to try it with the SN3 powering itself.

Personally I doubt this is anything to do with cables touching other cables, burndy not hanging free or any of that sort of voodoo. It sounds from your description much worse than that and I am now convinced it’s an equipment fault.

Best

David

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Just to verify, I cannot run the SN3 without the HCDR without plugging the blanking caps back into the SN3, correct?

I can drive across town and dig through my storage unit to get it but it would be easier if I could just unplug the HCDR and plug the AC back into the SN3

Agree with David that I don’t think it is anything like cables touching or stress on cables etc. I think I’ve narrowed the issue down at this point to the SN3 preamp section.

I do have an IsoTek Corvus power strip back there but it is all my subwoofers and router/networking stuff plugged into it. All the Naim components are plugged directly into the walls. I’m also using 3/4" insulation around any hanging cables to prevent them from touching any other cables.

One final related question - if I want to run the Luxman preamp in place of the SN3 preamp but use the SN3 amplifier section, I can just plug the source into the Luxman and plug the Luxman into the AV input etc of the SN3 and switch on AV Bypass, correct? This will bypass the SN3 preamp completely?

Correct.

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I’m not sure you can be sure of that because it depends exactly how Naim have arranged that circuitry. You could always give it a try though. If it’s better you know something, but if it’s not, you don’t really know much more. I suppose if it works without the SN3 blanking plug in place, then you do know something!

And yes you do absolutely need the coupling plug. It won’t work without it if you remove the HCDR. I see a trip across town in your near future!

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DDAB26DA-6EA4-40A5-8786-69F15C0517D8-815-000000FA522F4C64

Due to OCD I would be taking off speaker/sub ornaments and realigning the back wall treatment panels so it was perfectly in proportion and not offset like you have it on the back wall - just to rule out that possibility.

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Probably worth blocking that doorway too. You will need to let the plaster dry out before painting it of course. Do let us know how you get on.
Best

David

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The HCDR serial shows 2019 oddly though it is in the blank area after the 450xxxx and before the 465xxxx, whatever that means.

Thanks - unfortunately since that door goes into my office, I had to align the front wall bass traps (actually the rear wall for my home theater which is on the opposite side of this room) between the door and the curtain on the left of this picture.

If I aligned the system itself with the wall panels the system would be off-center in the room which is an acoustically poor choice.

So unfortunately it’s one of those aesthetic things I have to live with. I do have much more panels arriving in the next month that will better mask the front wall panels (diffusion panels of varying width and height that will go in front of that wall).

Also although there is some sculpture type stuff on the subwoofers none of the subwoofers have been connected for the duration of this experiment. Normally that sculpture would sit on top of the NDX2 where it does no harm.

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OK, so… anyway the HC is a recent build (around 2 or 3 years old). So it is not in need of a service.

I would still look to remove it & run without. YMMV - as always…

PS. Sorry - Maths failure here. Your HiCap is around 12 to 13 years old. So maybe due for a Service)

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Thanks yes I am going to run by the storage unit and dig out that plug so I can remove it.

I did just try to run the Luxman pre into the AV input of the SN3 and use AV Bypass but the noise was still very prominent in that configuration - so if it is the HCDR it was still plugged in and affecting the sound.

The only configuration I have tried so far that is completely free of noise and distortion is when bypassing the SN3 completely and running the NDX2 into the Luxman/Anthem combo.

I just A/B’d the SN3 and the Luxman/Anthem combo for my wife, and she confirms there is much more noise in the Supernait, and remarked without prompting the same instruments she heard clearly through the Luxman/Anthem that were not even audible in the SN3 due to the hash and noise.