Poor CD sound using 32/5 Hi-Cap 250

Having used and owned various Naim amplifers for the last 30+ years, I’ve presently got a problem I’m hoping someone on here can help with.

The present system is: upgraded LP12/Ittok/Karma 32/5 Hi-Cap Nap 250 with (later type) Mk1 Linn Kans -Kan 2 stands Nac5 and black snaics, Marantz CD67 player.
The 32/5 Hi-Cap 250 were serviced by Naim in Jan 2020 at considerable cost I may add, since getting them back I’ve had a problem with CD sound quality.

If the CD player is connected via BNC input using the fitted NA328/2 variable gain cards set at their lowest output setting, the SQ is terrible, the vocals and high end are hard/shrill and aggressive, the vocals especially are literally “shouting right in your face”

On checking inside the 32/5, the originally fitted 328 boards appear to have been replaced with 328/2 boards, prior to having the amplifiers serviced, CD sound quality was acceptable with the original 328 boards, but with the replacement 328/2 boards it’s horrid. Are these 328 boards not supposed to have a rolled off top end FR ? certainly not from what I’m experiencing !
The CD player is presently connected via the Tuner input, which is better but still not as good as I’d really like.
The amps have been on 24/7 since being returned and I’ve played loads of music through them, although I’m also aware they will perhaps improve slightly over a longer period as they settle/burn in.

Unfortunately due to the Valhalla failing on the LP12 I’ve not be able to try it with the serviced amplifiers, but I’m hoping it will sound fine.

Incidentally If I substitute a humble Cambridge A5 integrated amplifier in place of the Naim’s in the same system, CD sound quality is transformed to being very good indeed.


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I’d suggest you get your dealer, who presumably arranged the service, involved. Something certainly sounds amiss.

Thanks for your reply
The service was arranged through my local Naim dealer who I’ll be visiting tomorrow to discuss the issue. hope he’s got a flack jacket handy !
Just noticed this evening the power on bulb on the CB250 has failed already ! with less than a week’s use…average life of these bulbs according to the manufacturers should be 5000 hrs…

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A visit to the dealer hasn’t proved much help, he commented that the older CB Naim amplifiers were designed back in the day for Vinyl replay, prior to CD existing and therefore not being really optimal using CD as a source !
Up to a point I’d agree, but that does not explain why prior to having the amps serviced CD replay SQ was perfectly acceptable using exactly the same system.

I suspect the replacement 328/2 boards have changed the CD SQ for the worse it was definitely better with the originally fitted 328 boards, unless of course some other changes have also been made to the 32/5 that are not so obvious.

It will be interesting to hear how the LP12 sounds with the serviced amps once I get it working again.

Nonsense. My 32.5/hc/250 sounds great with CD. None of the problems you are now experiencing. Something is definitely off.

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Sounds to me like your dealer is giving you the run around. I would give Naim support a call, or maybe @NeilS has some suggestions?

Absolutely no issue running a good quality CD source into any CB gear. The 328 boards were introduced as a means of making early CD replay more palatable to those ears more used to vinyl. Does anyone remember the Micromega Logic CDP ? It got 5 star reviews when it came out and I bought one as my first CDP for use with a 42.5/110 combo. It wasn’t a good buy as the Naim gear just revealed how rough it was at the top end. I ended up trading it for a Linn Karik which was far more revealing and yet totally non fatiguing.
I think what’s maybe happened here is that your freshly serviced CB kit has opened the window a little too wide for your CDP.


The CD67 is a good player not some early days unpolished digital cd player.

Maybe, but it’s no Linn Karik either. Long unserviced Naim CB gear can sound a bit wooly and mellow compared to a freshly serviced set - like a different amp really.

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That’s very interesting, with you using the same CB kit, are you using a BNC input for CD if so with which cards 328’s /328/1 /328/2 ? or are you using a line input ie Tuner etc ?

I found decent cd sources to work really well into my serviced 32.5/Hicap/135s back in the day. This was with CDX2/XPS2, CDX2/555PS, CDS3/XPS2 & CDS3/555PS.
In each case, the cd player was connected to the Tuner input of the 32.5 via a DIN-DIN Hi-line cable.

As others have said, your experience would indicate that something is amiss.

Best regards, BF

I tend to agree with both Mr. Tibbs and HH.

The CD67 was a good budget player, but a serviced and effectively new 32.5/Hicap/250 is too revealing for it. Years ago I tried both a 67 and 67 SE (and a 63 and 63 SE) into a 32.5/HC/250 (olive for HC and 250) and they just weren’t good enough for me.

That said, it seems as if something is amiss, given that you mention the power-on bulb in the 250 failed. The other piece is that a fully serviced bit of Naim effectively requires break-in much like a new unit; this seems to be particularly true for CB and olive gear.

So: I’d contact Naim service directly and get their advice. I’d also check and verify setup - your system is VERY revealing of setup, and it’s very possible that there is a setup issue.

Hope the above helps!

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I hadn’t really picked up that the CD player was a relatively modest Marantz. I had a 32.5 Hicap and 250, with Mk 1 Kans for a good few years. It’s a fantastic combination but ruthlessly revealing. I used mine with an LP12 and Ekos/Troika but wouldn’t have let a Marantz near it. I suspect as others have suggested that the service may have opened the window rather too wide.

The acid test is to use the LP12. If that sounds ok then it’s a CDP upgrade, maybe to a CDS2. That said, the bulb failing sounds odd. It could just be one of those things but I’d feel happier if the dealer were to speak to Naim about it


Hi vinyl_rules,

Are you saying that the 328 boards were replaced at Naim for a different board revision? If so, do you have an RMA number for the 32-5?
Is the 250 connected correctly to the Hicap & not the 4 pin DIN on the 32-5?
I’m afraid a filament lamp can fail at any point in its lifetime, so that could be just bad luck.


I remember my CB 250 blowing lamps quite regularly, but that a long lasting non-filament bulb was introduced that solved the issue. It was shaped like a tiny tin can, with a flat top, rather than being a long thin thing with a pointy end. Surely Naim haven’t reverted to filament bulbs for the CB 250?

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We did have an LED replacement, but we had trouble sourcing them I seem to remember - plus we have lots of filament bulbs in stock!

Perhaps we should look into finding LEDs again, I think a resistor change maybe required too (?)


When I had the filament bulb it was a straight replacement, if memory serves. So, in the OP’s case, if you have fitted a filament bulb and it’s blown it’s just coincidence. This may sound harsh but with the high price you charge for service it’s really not on to be fitting bulbs that were deemed to be a pain back in the 80s. Just fit the proper led and don’t rely on people prising off the green button with a screwdriver and pulling out the bulb with a little plastic tube. That’s just rubbish.

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Point taken. :smiley:

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I had the BNCs replaced with RCAs and have been playing an Apollo/Qutest combo into a phono input using line level boards. Been alternating between a Chord Shawline and SL interconnect. Sounds great regardless of whether I use Phono 1 or Phono 2.

I previously ran a CDX XPS into the Tuner input using a Lavender interconnect. Sounded great too.

I will check which boards I have when I get back from running errands.

Personally I think this “chrome bumper wasn’t designed for CDs” stuff is nonsense. Julian said as much. CD always sounds great through my CB gear.

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The dealer is either bullshitting you or doesn’t know what he’s talking about, neither of which is encouraging. All amps of that period were to designed to work with line inputs, and CD is just another line input.

Still, I would look to test the turntable with the new system and/or a different CD player.