I’ve got an intermittent issue with my NAC 552 and/or ND 555 which is that the left channel drops out (it works fine when I press the mono button on the pre-amp so I don’t think it’s the power amp?). I’d be very grateful for advice and suggestions about the likely culprit, please. I’ve unplugged and replugged all leads. The pre-amp is still under warranty.
Do you have any other sources connected to the NAC552 to test. Otherwise, try a different input. If the result is the same then it may well be the ND555. In which case try the RCA Phono output.
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Probably a stuck relay in the 555; if switching to rca output it all works, then you have found the culprit.
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Thank you for the quick responses - this really is a useful forum. I have heard that stuck relays in the pre-amp can be an issue (didn’t know there is also a relay in the 555). The trouble with intermittent faults is that they are so hard to pin down.
I have sent the units to the very helpful team at TomTom Audio who are seeing if they can get to the bottom of the issue (including by connecting different sources). I can hear the ND555 source faintly even when the pre-amp selects a different input, which suggests to me that the pre-amp selector may not be working right?
Same thing happened to me a while ago. doing all the tests with different sources in the end the culprit was the nd555. in practice it worked in one channel with the din connection, but it worked correctly with rca connection. Brought in for assistance it turned out that the culprit was the rca circuit relay (although with rca it worked). However, changed 3 relays and everything is back to working fine.
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That is so valuable, thank you. I will pass that on to TomTom. Did you notice any difference in the sound through the rca rather than the din?
Same here a couple of months ago with the ND555 it was a stuck relay.
Sent off to Naim via my dealer and a super quick turn round by Naim team.
Onestly, no difference for me.
I’ve been quoted £800 for Naim to replace the relay in the ND555 (which is out of warranty). Does that sound right?
My repair was under warranty and I think a lot of the other people on the forum also had the work done under warranty.
As this fault is common and impacts a relatively new product and has been experienced by a number of people on this forum alone - you’d think it would have qualified for a product recall.
Chances are if you own an ND555 at some stage sooner than later you’ll experience the stuck relay issue.
For a known quality issue that doesn’t seem right to me… 
it should be f.o.c.
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I’m surprised it’s not still under (UK) warranty as the ND555 is only just 5 years old. Did you take out the additional 3 years extended warranty when you purchased the unit?
I bought it second hand and it’s over 2 years old. The extended warranty doesn’t transfer to the new owner. Apparently £800 is the standard charge for a repair, which seems a lot to replace a relay to me.
Ah OK, yes, as second owner you only get the original 2 years as it’s not transferrable. Did you purchase it from Tom Tom Audio, another dealer, or privately?
I bought it from Lotus HiFi. TomTom are kindly looking into this for me (I’ve bought quite a lot of other stuff from them new) and will send it back to Naim. I won’t be terribly impressed if Naim want to bill me £800 to fix a simple quality issue with their top of the range streamer but will let you know how it plays out.
Thanks. I guess had it been bought through a Naim dealer such as Tom Tom Audio then some goodwill may have been leveraged. FWIW, I think that £800 is the standard UK charge for a 555 repair out of warranty.
That’s what I’ve been told for the 552. I don’t know what the standard charge is for a ND555 (if there is one). I’ll let you know what it ends up costing. At the moment, it is with TomTom along with the NAC552 to make sure it is the streamer (rather than the pre-amp) which is the problem before sending it back to Naim. TomTom have been very helpful. I think it will ultimately be up to Naim as to what they charge to replace a cheap part like a relay. If it’s “standard repair charge” or nothing, then I don’t really have an option (other than to just use the RCA outputs rather than the DIN, which I’m not very keen on).
Sorry, I mis-typed - Meant 555 (now amended).
Exactly, or at least honour the repair cost. If not, poor show.
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