552 DR upgrade advice

I have just received back my DR upgraded 500 and 552 but I seem to have a problem with the 552 insomuch as the volume seems much louder for a given position than it was before the upgrade and I almost can’t get it quiet enough for my normal listening. I used to use the range between 7 and 8:30 (clock face) and if I wanted it really loud I could go to 9-9:30. However, now it seems far too loud by the 8 o’clock position and I find my normal listening range has almost no movement of the volume control from minimum. I am feeding it with a Linn Klimax DS/3 but have also tried a Denon cd player to rule out a faulty DS both of which exhibit the same behaviour also, using my AV processor, the unity gain setting remains unchanged thus ruling out the NAP 500 DR. So, before I think about sending it back, could those who have experience of this upgrade tell me what you have found? I know it will need to be “run in” but is this normal? Other than that it does sound fantastic.

Also, does anyone know the maximum attenuation that the 552 can actually provide for a given input?

Thanks in anticipation of your help.

This has never been mentioned previously as far as I am aware. I would ask you dealer to speak to Naim straight away, as it doesn’t seem right.

I wonder if the volume knob has been re-aligned slightly differently on the pot’s axle. There’s nothing else I can think of that would cause this.

Maximum attenuation is down to the ALPS pot, which won’t attenuate down to nothing (infinite), but i don’t know the quoted figures - for maximum attenuation, you would need to engage mute.

Thanks both, I don’t think it can be the knob positioning as it does attenuate to almost silent when turned right down. Its just the useful range that seems reduced

Do you know if the pot. was replaced as part of the service? I suspect there is some sample variation between individual pots…or is it something else that has caused this change?

The pot wasn’t changed as far as I am aware. It was a full service and DR upgrade.

There should be a full list of components changed, so you should be able to see from that - although I believe with a DR upgrade, there isn’t much they don’t change.

I was given no Naim work note for the head unit but the one for the 552 PS simply says service and upgrade to DR , changed logo, reservoir caps, applied DR upgrade and tested ok.

I have checked this evening and the volume control has no effect for the first 10 degrees of travel from minimum (4.5mm) then it goes to my normal listening level in the next 10 degrees (4.5mm) and to far too loud in the next 10 degrees (4.5mm) so the usable travel for me during normal listening is 5mm or so which doesn’t seem right albeit there is no sense of it sounding off at all.

Then I would certainly ask your dealer to investigate.
The pot on my 282 has a vey small usable range. I found adding a Chord Hugo makes a very effective volume attenuator :slightly_smiling_face:

Got my 552 a few weeks ago DRed. Nothing has changed at the volume setting. It’s like you describe above 9 - 9:30 o’clock very loud, at 8 o’clock normal listening. Sometimes the points shift slightly, but not very much.

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Thanks thats helpful. I guess I need to compare mine with another one in order to know whether I do have a problem. I’m not keen to send it off again if this is within normal parameters but finding someone else with a 552 maybe a challenge as the dealer that arranged the upgrade doesn’t have one

I’ve noticed a difference between my old 52 and 552. The 552 seems to have a little more gain on the volume pot. With my 52, about 10;00 on the dial, was concert loud. With the 552 it’s now around 09:30.

What I have sometimes noticed, especially during fresh burn-in, or when something’s off in the system, is a compression of headroom, which makes things sound loud even at 08:00 on the volume dial. This tends to go away after time or, alternatively, I’ll end up dismantling and rebuilding the system.

If there is no perceivable change over the next few days you could try going down the ‘rebuild’ route? At least you will have eliminated all possible options?

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