Naim bananas and Nait 1

[Martyn Miles]

To correct, I didn't say 'ordinary' cable.
I need to correct my post.
Evidently the cable wasn't 79 strand.
It was a flexible type ( freely available ) recommended to my friend by an ex. Naim R & D employee.
He appreciated that Naim cable wasn't the most easily fitted cable, and research had been done on alternatives.
I hope this clarifies matters.

 

[booja30]

IIRC the important parts are the length (min 2.5m) and the separation between the two conductors (~3cm?) which give it the necessary properties. K20 is fairly cheap by the meter and meets the requirements, and is like a wet noodle flexibility wise compared to NACA5. I thought it was worth pointing out so someone doesn’t read this thread someday and end up frying their amp.

 

[Gervais Cote]

IIRC the important parts are the length (min 2.5m) and the separation between the two conductors (~3cm?) which give it the necessary properties. K20 is fairly cheap by the meter and meets the requirements, and is like a wet noodle flexibility wise compared to NACA5. I thought it was worth pointing out so someone doesn’t read this thread someday and end up frying their amp.

My Naim NAP 110 runs 8 Celsius degrees higher for a given sound pressure (dB) and has a harsh treble when hooked up to an entry level 2x 16 gage speaker cable in comparison with either the NACA5 or Linn K20.
Must means something......
I saw similar situations with other British amps that don’t have any inductor (coil) at their output.

 

[colasblue]

Nothing disastrous is likely to happen if you use cable other than NACA4 or NACA5 or the same sort of construction from another supplier. Van Damme make a speaker cable like it for a lot less money.

The cable was introduced quite a long time after the actual amp design so it isn't true to say that amp was designed for this specific cable. It does seem to sound best with that particular sort of cable though.

I've used Naim amps with QED 79 strand cable and they're fine with it but a proper Naim cable is a sonic upgrade.

They will also work perfectly well with two lengths of RS 56 strand cable (single core) lightly twisted together.

 

[TimF]

Another reasonable cable that works very well with Naim amps is Supra Classic, available in several various AWG to suit. I have used the Classic 6.0 for ages it seems, along with Linn K20.

 

[Hazelberry]

I couldn't believe NACA5 when I first encountered it. Why Naim promotes a speaker cable with practically the flexibility of rebar mystifies me. It's as if they go out of their way to claim that such a dreadful user experience is a beneficial one.

Actually, one thing. Can it be bent with heat?

 

[MJS]

I couldn't believe NACA5 when I first encountered it. Why Naim promotes a speaker cable with practically the flexibility of rebar mystifies me. It's as if they go out of their way to claim that such a dreadful user experience is a beneficial one.

Actually, one thing. Can it be bent with heat?

Yes, Use a hairdryer to soften it up and then bend it around your fireplace, bookshelf etc. When I designed the Witch Hat N2 speaker cable I used its flexibility as a selling point.

 

[TimF]

I couldn't believe NACA5 when I first encountered it. Why Naim promotes a speaker cable with practically the flexibility of rebar mystifies me. It's as if they go out of their way to claim that such a dreadful user experience is a beneficial one.

Actually, one thing. Can it be bent with heat?

Totally agree, funny, flexibility of rebar....I guess we aren't true audiophools if we cannot endure the pain and agony of silly crap like this!

 

[Bob McC]

It's bad advice to tell someone to just use ordinary cable with old Naim amps. They were designed for a specific type of cable (which is a shortcoming IMO). There's something missing on older Naim amps that other amps have. @Arkless Electronics would be able to say what it was but he's not on PFM at the moment.

If the correct cable and minimum length isn't used then the amp can become 'unstable' and fry. So K20 (or something with similar capacitance), minimum 2.5m each side, is what you want for CB and olive amps.

Feel free to take @Martyn Miles's advice, but you risk damaging the amp. I'm not a cable believer myself -- I use 2.5mm^2 stranded copper or extension cord cable in a pinch (for non-Naim amps of course).

Twaddle.
I am looking at an old Naim product leaflet that predates Naim NAC4 when they recommended RS cable twisted at one turn per metre for their amps.
QED 79 strand was electrically identical.
I ran a NAP 160 for over ten years with both types.
It worked perfectly as long as you followed the length advice, which wasn’t 2.5 m incidentally, it was 3.5 m.

 

[booja30]

Twaddle.
I am looking at an old Naim product leaflet that predates Naim NAC4 when they recommended RS cable twisted at one turn per metre for their amps.
QED 79 strand was electrically identical.
I ran a NAP 160 for over ten years with both types.
It worked perfectly as long as you followed the length advice, which wasn’t 2.5 m incidentally, it was 3.5 m.

You've said yourself the cables needed to be twisted. Great, do that. But my point was that just unknowingly plugging any cables into the back of an old (CB or olive) Naim might cause it to be unstable.

It doesn't have to be NACA4/NACA5/K20 -- I didn't say that. But If you buy cheap K20 then you don't have to remember to twist your cables when you set them up.

 

[JimmyB]

I've run my Nait with NACA4, K20 and Heybrook wire (the single strand stuff, Heywire?). It's never seemed to have had a problem but then I've never run it naked and tested it for straining.

Always normal banana plugs and I took the soldered on straight bananas off the NACA5 and replaced with Michel plugs @90degrees to reduce strain on the sockets.

Currently I think I've got Supra running from it 'cos it's white and a better match for the decor.

Not sure what this says but maybe I'm just not pushing it hard enough to blow it up (particularly with the Heywire)

 

[Craig B]

With classic Naim lacking a Thiele network (as opposed to a Zobel network, according to @Arkless Electronics), the minimum loop inductance (specified in µH/m) should at least come close to that of Naim's specified minimum length of 3.5m of their own cable (1µH/m for NACA5, therefore circa 3.5µH total as minimum). Balancing this, the maximum parallel capacitance (specified in pF/m) should not far exceed that of Naim's specified maximum length of 20m of A5.

AIUI, it is the twisting of, or increased spacing between, the two conductors that raises loop inductance for a given wire size/type. As mentioned in another thread on here, I put together a spreadsheet with a lookup table containing the published electrical specifications of those popular speaker cables for which the maker has bothered to publish such. Any particular choice made is then compared to Naim's own minimum (based upon the total loop inductance of 3.5m A5) and maximum (based upon the total capacitance of 20m A5) lengths. IOWs, the calculations performed return the minimum and maximum lengths of the chosen cable that match the key Naim minima/maxima electrical specs.

What I find interesting is that many cables require quite a bit more length to meet the minimum inductance, but are then approaching the upper capacitance limit. For example, QED 79 Strand need be 5.3m to meet 3.5µH, however, 5.52m matches the 320pF parallel capacitance of 20m of A5. At least the QED 79 returns a useable range; Kimber anything is way OTT either way round, 4TC for example, requires a 15.56m minimum length (for 3.5µH) vs. a 2.35m maximum length (for 320pF); with the 15.56m necessary to get 3.5µH resulting in 2116pF!

P.S. The 'shocker' is Naim's own Super Lumina, 4.73m minimum vs. 4.82m maximum to match 3.5m and 20m A5 respectively. 20m of 'SL' would present 1328pF! Thankfully, this is typically available in 3m, 5m, 7m and 9m lengths; £5,937 for the latter (598pF, so 'only' £9.93/pF!).