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NACA 5 optimal length

T

topk

pfm Member
I have read on another forum that you need at least 3.5 meters of NACA 5 speaker cable if you use Naim amps. However, the optimal length would be at least 5 to 7-8 meters (optimal) to have the best sound quality - harshness decreases, more body in the midrange...etc.

Do you have experience in that regard? Is it worth "upgrading" from 3.5 meters to - say 6 meters for NACA 5?
 
This is an old story. NAC A5 length has little or nothing to do with sound quality. It has to do with the correct inductance or capacitance 'seen' by the older, and now perhaps the costlier, power amps, which had no Zobel network on the output stage and, so, the type and length of the cable was actually 'designed' into the amp's specifications. The risk - never witnessed by anyone, so far, thus still belonging to the realm of urban legends - was that using high-capacitance, 'special' cables, the amp could 'oscillate' at very high frequencies.

I don't think you have anything to worry about with any length between 2 and 10 mt; Naim says that over 20 mt one could detect a mild loss at 20 Khz.

Hope it helps.
Max
 
It's such horrible stuff though on a practical level. Has to be wrestled into position. I've thought similar to you, but there's nowhere to hide all that cable. I'm running on just two meters so I'm well under the recommendation, sounds good to me though.
 
I used 6m Naca5 many years ago,after getting grief from her indoors i cut it in half.I couldn't hear any difference and sold the left over cable on ebay.I was using a Nait 5i at the time,which was not upset by the shorter length....
 
Rubbish, use any length, i have with olive gear in the past, no difference in either sound quality or "upsetting" the amp.
 
I use, and have done for many decades, 11+ metres on various speakers and both 135s and my current valved mono's. Unless you run them to the garden shed at the bottom of the garden you've no worries.:)
 
Back when I had DMS isobariks on the end of my 250 I experimented with lengths of 3.5, 5, 6, and 11 meters. The difference in sound quality between lengths was minimal with the bass a gnat's hair more prominent moving from 3.5 to 11 meters. (The differences in lengths 5m and 6m were inaudible.) I suspect any exaggerated differences reported are more likely due to pin/socket alignment issues affecting the quality of the electrical connection due to the stiffness of the cable if not routed carefully from amp sockets to speaker sockets.

I have to agree with a friend who worked at Naim that told me to use the length it took to connect my 250 to my speakers - no more and no less ;-) so I ended up with 6 meters after finalizing the system layout in my room.

Ohhhh...and Max is correct.. Paul S from Naim once posted there's a gentle but measurable high frequency roll off after 6 meters.

FWIW, I would not go below 3.5 meters with older Naim amps since the manufacture doesn't recommend it. The cost savings isn't worth losing sleep over whether they're right or wrong.
 
I started with a 2.9m run when I first got my 202/150X combo & at times I felt the top end was a little forward at times. I swapped to a ~5m length & didn't notice the issue anymore. Maybe I was imagining things but I don't think so in this case as if anything I'd prefer the shorter length as to not have to worry about having to dress the additional length that wasn't required in that setup.
 
Perhaps those on here maintaining that under 3.5 metre lengths will not compromise older Naim power amps would like to inform the company of their error in insisting on it for years.
 
That minimum length must have depended on the speakers used. Anything with piezo, electrostatic or other exotic tweeters is hazardous
 
martin clark said:
Use lengths just long enough to reach from the amp(s) to the speakers. It's all you need, truly.
Click to expand...

Agreed and don't forget to calculate the length using Imperial measure
because as it's British equipment, metric units will not sound right.
 
I've used five metre speaker cables for many, many years - but if you don't place your amps between the speakers it's difficult to use much less.
 
I've witnessed a NAP 90 go into oscillation, but only under extreme circumstances, ie it was connected to AQ cable, then someone disconnected the speakers without powering down the amp. Got very hot, but survived.
 
I’m here to reply to this five year dead thread to report a 7m run of Blue Jeans Cable BJC10 sends my CB nap250 into oscillation. Going back to the NACA5 solved problem.

so, it’s true.
 
Maxbertola said:
This is an old story. NAC A5 length has little or nothing to do with sound quality. It has to do with the correct inductance or capacitance 'seen' by the older, and now perhaps the costlier, power amps, which had no Zobel network on the output stage and, so, the type and length of the cable was actually 'designed' into the amp's specifications. The risk - never witnessed by anyone, so far, thus still belonging to the realm of urban legends - was that using high-capacitance, 'special' cables, the amp could 'oscillate' at very high frequencies.

I don't think you have anything to worry about with any length between 2 and 10 mt; Naim says that over 20 mt one could detect a mild loss at 20 Khz.

Hope it helps.
Max
Click to expand...

It's a Thiele network (inductor and parallel damping resistor) that the Naim amps don't have. They do have a zobel (capacitor and resistor to ground) at the output. I have removed both from Avondale amps and they were fine as long as the speaker cable is low capacitance. It is said that you can't hear a zobel or Thiele network. I disagree.
 
I remember wanting to try Kimber 8TC with my Olives. I was concerned about the Naim advice so I wrote to the dealer, a well known dealer. They stated that I could use the Kimbers without issue. So I cautiously gave it a go.No oscillation or overheating and the sound was a little more subtle, calming a slight hardness in the treble that the NAC cable produced. Was still unsure though and a little nervous so resorted back to the NAC in the end.
 
Yes it's a thiele network and the cable to avoid are the litz type or hyperlitz type because it has very high capacitance and too low inductance.
I've used the Hitachi 102 ssx original with no problems and it was a bi-wired 4m set and also a 4m set of Van Damme hifi series 4mm which probably ideal.
I wouldn't use something like Goertz cable though or electrofluidics.
I think it's more of a problem with older Naim power amplifiers than the new stuff.
 
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