I purchased a pair of Cardas Clear Sky X4 in about a 17 ft length to pair with my Nait XS3 and Monitor Audio Gold 100 5G speakers. Because of the long run, I wanted a good quality cable.
After hooking up, the speakers were emitting a humming noise that has never happened before with any other cable (long or short).
I spoke with the sales person and they said that:
“Naim amplifiers like yours have unregulated outputs and as such, that is the issue. The Clear Sky has too much capacitance for the Naim amplifier you are using with it. Obviously other amplifiers with conventional designs ( like your Benchmark) have no problem using that cable at that length. The length is a major issue along with the unregulated outputs of the Naim amplifier. It is just NOT a great idea to run the speakers that far from that amplifier- eventually, it will damage the amp. Naim gear like this is designed for desktop to small system use and was never designed to push 20 feet of cable, not to mention the impedance curve of those speakers.”
I’m not sure that is correct, but now I’m questioning my setup and whether long cable runs are okay for the amp. The speaker/amp combo has been great for at least 3 years now. I didn’t know cable capacitance played a major role in compatibility. Some input from this group would be appreciated.
It’s not about the regulation (FWIW most amps are unregulated - ironically Naim are one of the only makers of fully regulated amps, although the NAIT XS3 is not one of them), however, Naim amps don’t have extra induction networks on their outputs, relying instead on the speaker cable. They like a speaker cable with low capacitance and moderately high inductance. More info on this here;
Incompatibility of speaker cables with Naim amps gets worse with shorter lengths, not longer. (Not that 17 feet is particularly long in terms of what the amp can handle.) The problem is that you’ve chosen an incompatible type of cable. Either use Naim’s NACA5 or another cable known to be compatible such as something from Chord, Tellurium Q or others and you’ll be fine.
The other issue with Naim amps is their sensitivity to “capacitative coupling” which means that speaker cables shouldn’t be run together for any length, in trunking for example.
OK, this thread has scared me a little bit. I had no idea the speaker cables are that critical and could potentially even damage the amp? Is there a list of ‘compatible’ cables somewhere? I have AudioQuest Rocket 33 cables and everything is working fine, but now I am worried. I can’t find information about ‘capacitance’ or ‘inductance’.
I appreciate the responses. Just for the sake of conversation, I have two other cables I alternate between. While I’ve never heard any humming, would you expect any long term issues with these listed below? Echoing whatu1tme2b asked, how do you figure out cable compatibility if you didn’t want to use Naim’s cable?
Kimber 8TC
DH Labs Q10 (external bi-wire)
Also, is it better to run a long speaker cable or long-ish interconnect? Being unbalanced RCA, would 12ft be a problem?
The 8TC is high capacitance and low inductance, so the exact opposite of what a Naim power amp needs. As an experiment I once tried my own 8TC (that I had been using on some tube amp) on a NAP250.2 and it not only sounded pretty poor but the amp ran hot, so I removed it before any damage was done.
Naim traditional systems liked to run short i/cs and long speaker cables - this also had the advantage of allowing the system to be away from between the speakers.
Unless the brand publishes the spec’s, its not easy.
However, Naim will happily run with normal twin (2 core) (parallel or twisted) pairs, the list is long and many.
I would just avoid the unnecessarily complicated types such as quad in addition to the real no-no’s of Litz or woven/plaited types.
Close coupled or twisted pairs would typically have middle of the road inductance of aprx 0.5uH/m so a longer 5m (or more) length would be better than 3.5m.
How are you supposed to know what type a cable is? I am using AudioQuest Rocket 33’s.
My Nait 5si is not running hot when using these cables. Is there any danger in using cables that could be ‘incompatible’ with a Naim amp?
A Naim amp is consumer electronics and the cables are pretty main stream. Not something that only professionals buy and install. I certainly do n’t have deep knowledge about all that is said here…To be honest, I just can’t believe that there might be any potential danger.
My dealer even recommends AudioQuest Rocket 33/44 with Naim amps. I remembered seeing that when I bought my amp 5 years ago. I just checked their web-site and they still do.
Not necessarily, yes a quad cable can be used for biwire, but it can also be wired as 2 conductors for each + and -.
Whatever a quad config makes for increased close proximity area between + and - resulting in higher C and lower L.
I understand, there is no satisfactory answer.
It’s a shame on those cable vendors who do not publish spec’s such as C and L.
Same to some extent with dealers, they tend to recommend what they have in stock or an agency for.
Maybe this is a stupid question: If a cable can cause amps to run hot, does that mean the situation is unsafe and a possible fire hazard? My amp is not running hot b.t.w
It would be a shame if my apartment burns to a crisp due to a cable being ‘incompatible’ with a Naim amp
The worst case scenario is that the amp would reach 70°C and shut down automatically, so there is no safety risk.
Naim offer cables that are optimal for use with their amps, and provide the inductance, capacitance and length requirements against which other brands can be compared. Other cable brands or dealers should be able to provide information about compatibility of their products. If they can’t give you those reassurances, look elsewhere.
