I may be new to this forum but not Naim Audio equipment. I’ve been an owner since the mid 90’s starting with the ‘slim’ olive products of NAP 90 & NAC 92 then, like many, moving up through the range but never quite reaching the summit. For me, a degree of pragmatism and the law of diminishing returns applies here.
My reason for breaking with tradition and writing this post is simple. During a recent search for my ‘end game’ speakers I listened to and very much liked, the ATC SCM50 active stand-mounts and therefore wanted to find out the best way to connect them to both my Naim system and a pair of REL S/510 subwoofers. I was given lots of advice through dealers near and far as well as forums such as this one. The problem was that the majority of advice I gathered was contradictory. Everyone had their own ‘correct’ advice and I became a little confused. However, my determined streak took over and to that end I went back to first principles and contacted ATC, Naim Audio, Design-a-cable, Canford Audio and Orso Audio in search of the ‘real’ correct answer.
Forgive me if I am being too simple here but the ‘problem’ I encountered stems from the Naim NAC252 and Supercap producing an unbalanced output signal. The potential difficulty lies in the detail as the ATC active speakers ‘require’ a balanced input signal. There are two main schools of thought here in regards to a solution. One is to use a ‘pseudo’ balanced cables from the Supercap directly to the active speakers (such as this one) whilst the other suggests using a transformer/converter provided by such companies as Canford Audio (here) or Orso Audio (here). Digging further there are also active and passive options of the converter route. Confused yet? I was!
To cut a very long story short, the answer is to connect directly from the pre-amp/power supply combo to the active ATC speakers using a pseudo ‘balanced cable’. A simple search for “four pin din to xlr’ will reveal a suitable offering from Design-a-Cable for less than £100. The cables are supplied as a stereo pair and are designed for just this kind of scenario. As it turns out, the very source of the issue (NAC 252 & Supercap) also aids the solution: the relatively high output voltage of the 252 is more than enough to ‘drive’ the speakers (ATCs words not my own).
During my quest I did find that the design Engineers at ATC don’t exactly all agree with this school of thought but the majority won my vote. I think this might be where the two different schools of thought might have originated. However, they were actually brilliant in answering my ‘noddy’ questions and did state that the majority of their customers who also own Naim equipment use ‘pseudo’ balanced cables.
Some however do go down the transformer/converter route. Why? In the words of ATC and Naim, a transformer/converter would come into play if a system issue (such as interference) was encountered. ATC said that an active transformer would be best (they strongly recommended Lundhal) but if not really required it would simply act as a weak link in the signal chain. In my trek down this road I found a small audio company called Orso Audio which are one of their distributors in the UK and were recommended to me by Lundahl themselves. If required they can make a custom box with converter/transformer inside with DIN inputs and XLR outputs so that no custom cables would be required.
Furnished with this information some might remain hesitant in using a ‘pseudo balanced’ cable for fear of causing unwanted damage to the Naim equipment. To quell my own fears I contacted Naim again, they said…
“No, this should put no strain on the pre amplifier or power supply. All the cables are doing is presenting your speakers with line level for the internal amplifier to amplify.”
And when asked about how to connect they also said…
“To make this setup work you will simply need to get two 4 pin DIN to XLR cables, which will run out of the Supercap directly into the two speakers. It is not possible to make your system balanced as the preamplifier is only able to supply unbalanced signal, so it is important to not run your cables alongside any power cables as unbalanced cables are far more susceptible to picking up noise.”
As it turns out, I was (as usual) digging too deep into a subject and got caught up in minor detail. The correct answer was unusually the most simple (and cheapest) solution. Before signing off may I just say that (for anyone who has any doubts about me) I absolutely do not work for any of the companies previously mentioned. I, like you, am just an average ‘Joe’. I have saved all emails from the likes of Naim and ATC just in case someone needs a little more reassurance as I once did. May I also say that I was a little disappointed in the ATC dealers I visited. All were more than one hundred miles apart and all never knew the answer or had suitable cables at hand to offer for a home demo. I found this absolutely astounding. Knowing that Naim go rather well with ATC I expected better from shops who sell high end products. The cables are not expensive and take up little space in a stock room so I therefore fail to see a good reason for this shortfall.
And for the final piece of evidence, well, it’s my ears. I am currently sitting in front of my system with a pair of active ATC SCM50s and they do sound rather good. It’s strange… the infamous Naim ‘hum’ is no more. First time in thirty years I’ve not had that.
In my journey I cannot applaud enough the efforts of ATC and Naim for their answers and efforts. At one point ATC contacted Naim directly to make sure the information they were giving me was 100% correct. This, for me, is the ‘gold standard’ in customer service. So for Tom and Charlie at ATC, Alex at Naim and Rob at REL Acoustics… I owe you at least one beer for the time spent and countless emails sent in reply to me. If only all customer service was this good.