NAP 500 + Mogami 2972 speaker cable: what minimum length?

I’ve been using Mogami 2972 speaker cable for years, but have a 9metre pair because my previous listening room demanded it. I could now trim these to 5 metres to get a neater cable run in my current room, but will 5 metres work in terms of capacitance and inductance for safe running of the NAP500 DR?

Anybody have an idea?

2972 is a 4 core cable, how do you have it connected?

Hi Chris,
I have red and yellow twinned to +ve, brown and orange to -ve.

This was the recommendation of John Burns at Pear Audio.

Should have given specs: from Mogami website, Inductance seems to be between 0.6 - 0.7µH/m depending on config.

Capacitance range:



You want the 1-3 wired figures Kevin. I have mine wired the same as recommended for this cable. Can’t remember what the reqs are for Naim amps.

I believe that the inductance when wired in diagonal pairs would be reduced, which may not be optimal for a Naim power amp, and which would be compounded by the reduced length. My understanding of all this is somewhat limited though, perhaps Mogami would be able to tell you, as at least they bother to publish their cable specs unlike many suppliers.

PS - Even if you don’t reduce cable lengths I’d remake those connectors. Worth getting 4mm plugs soldered on.

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Those connections look b… awful. With @james_n here. Get them remade, ASAP.

Hi James
I see at the bottom of that page that it says wiring diagonal pairs “greatly reduces mutual inductance.” Naim power amps don’t like low inductance, so I wonder if this would be a problem?

Hi Chris - Moderate capacitance is fine (i think Superlumina is higher than A5 at ~66pF per metre)

As for inductance, the 3.5m min naim recommends gives a value with A5 (1uH per metre) of 3.5uH so Kevin’s 9m cables (in the 1-3 config) gives 6.3uH. Taking this down to 5m gives 3.5uH so meets the recommended value.

@Mike-B probably has all the specs for the various Naim cables.

I would guess this is not a huge problem with a conventional stranded copper cable like this, it’s not as if it’s Litz stuff. Still, I don’t entirely understand how one would interpret their comment about greatly reduced mutual inductance when they are wired as diagonal pairs. I presume the quoted inductance figure of 0.7 applies when you are only using two of the four strands as opposed to pairing them.

I don’t have any that is reliably verified or published by Naim other than for NACA5
Inductance = 1uH/m & capacitance = 16pF/m

However getting back to the OP ( @KJC ) & the question of Mogami W2972
Its capacitance is slightly higher than ideal, but not excessive & not worth considering IMO.
However the far more important inductance - thats the output load the amp is looking for - is not so far off OK if (IF) used as a 2 pair cable
The spec shows 0.7uH/m between 1-2 & 1-3.
But it doesn’t show what it is in 1+3 - 2+4 ‘quad’ config.
5m x 0.7uH = 3.5uH & thats the minimal recommendation
My concern is that in quad it will measure lower than the 0.7uH/m spec & will actually be lower than the Naim recommendation


Hi James,
I have thought about doing that since it seems sensible to me,but it was John Burns recommendation to use the Pomona screw/crimp paired banana plugs because he says in his experience it sounds better than any soldered connection. I do find the fixed space housing helps keep the plugs in the downward facing sockets very securely, particularly useful when shifting the speakers around on their castors…
But, yes, I am still considering using a better soldered plug. Recommendations welcomed. What are yours in the pic?

I suspect the spacing is the same as that on Naim plugs, which is certainly what I would be using at the amp end, although possibly less critical at the speaker end given the gold plated sockets on the Shahinians.

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Hi Kevin - Well I wouldn’t argue with John Burns as he’s the Shahinian expert but I personally prefer the longevity and consistency of a soldered joint. The plugs I used when I made up my speakers cables came from Chord along with the heatshrink - nothing fancy just gold plated Deltron types. If I ever go back to Naim amplification then I’ll just replace the amp end with the Naim SA8 connectors.

How’s the dedicated listening room settling in ?


Thanks Mike,
I think (?] Mogami are always recommending using all 4 conductors and their terms of 1-2 vs 1-3 just refer to how the wires are paired up for connection e.g.

Neighbouring pairs, 1+2 (to +ve) & 3+4 (to -ve)
vs the alternative
Diagonal pairs, 1+3 & 2+4

and I assume the Mogami technical specs refer only to these 2 possible configurations.

I’m using 1-3 , so from your calcs it seems like a 5 metre pair might be pushing things a bit. Maybe I’d be better going 6 or 7 metres just to be safe…

Hi Kevin, I’m reluctant to comment on what the various 4 wire connection configs will do.
However ‘neighbouring’ pairs will probably result in the same/similar 0.7uH/m as it is with single cable, on the other hand I suspect diagonal (quad) pairs will be less, but how much less ??? err ???
If I had some quad cable in the bits box I would get the meters out & find out.

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The way I read it from the spec sheet, they are just giving the inductance figures for one pair of cables. Otherwise the ‘remark’ at the bottom of the page about using diagonal pairs doesn’t mean anything…to me, anyway, but I am easily confused!

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I’ve edited my previous post as reviewing it again indicates my grey cell logic has gone fuzzy
I meant to say there will be less inductance using the 4 wires in a diagonal config.

The Mogami spec sheet remark - “Connecting the conductors as diagonal pairs greatly reduces mutual inductance” - supports my supposition that wired as diagonal (quad) double pairs will result in less inductance than single pairs & as such is less ideal for Naim output stage loading. Its a pity Mogami don’t give an actual number, ‘greatly reduces’ is not a number

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I guess the simple answer would be to ask Mogami - they seem like the sort of company who would give you a straight answer.

I dare say there’s no real cause for concern here. Still, if it was me, I wouldn’t spend £20k on a power amp and then use speaker cables that were kind of OK, I’d want the match to be bloody perfect!