Do impedence requirements for speaker cables apply to all Naim amps?

Hello. I am trying to set up a Naim system at an off grid cabin, and want to utilize the runs of speaker cable that are already in place and running through the walls. Unfortunately, it’s just 16 gauge lamp wire (it was installed in the 1980’s). I know about the need for proper impedence matching for the speaker cables for the legacy Naim kit (thus necessitating the recommendation for long runs of NACA5 or SL with those amps). However, I’m wondering if any of the newer amps no longer have this requirement? I was going to take an old Olive 250 that I have and install it, but I remembered the speaker cable requirement and realize I have no way to run NACA5 without taking apart the house, which would be frowned upon. I’m wondering if any other Naim amps could be used?

I use 5m runs of Chord Sarsen with the Atom In my office where NACA5 would be impractical. It is very slim — no thicker than a lamp flex — so I wonder if there was any way you could replace the wiring with similar cables.

Roger

I suggest you google “Ben Duncan Pure Henry”

I have no experience of this item but Mr Duncan seems to be well respected in the audio community and these items seem to have been designed with Naim and similar amps in mind

I’ve no desire to start a barney here, but I have often wondered whether the apocalyptic cable warnings we read in the manuals really can be taken at face value. I’m totally happy that NACA4/5 gives best results, but does the use of other cable really cause actual damage?

So, hands up anyone who has genuine first-hand experience of a Naim amp being properly damaged by the use of non-Naim speaker cabling.

Anyone?

Mark

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I have been running my QED Silver 25th Anniversary cable with my NAC62/NAP140 without issue and it sounds great (although the stars would lead to an explosion!!).

Changed today to Linn K20 (which Sounds beefier but not as “sparkly”) so I am sure the national grid will now be fine and I can call off the NASA flypast.

Some lucky eBayer will get the 9m of QED and be perfectly happy as I have been over several sets of speakers.

I’ve briefly run a particular speaker cable on a NAP250.2 that caused it to get extremely hot. I didn’t leave it connected long enough to cause any lasting damage - at least not that I’m aware of anyway. The performance of the map did go south after about 6 or 7 years though, so maybe it did have a deleterious effect on things…

My amp exploded in flames when I went off piste with non naim cable :rofl::rofl::rofl:

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As usual, ignore all words up to and including the “but” :slight_smile:

“I wondered if this amplifier needed the inductance provided by certain speaker cables to maintain stability and was told “no, you can put any cable on it. The last version, the NAP 250 Mk2 was also cable tolerant. It’s only really the older models that you have to be a bit careful with. I also asked Steve whether the DR amps have exactly the same NA 009 transistors as Statement and was told: “the Statement ones are selected but they are exactly the same. What we do on the selection for Statement is take four that were made from adjacent silicon dies and have exactly the same parameters. Because we use four in parallel on both negative and positive rails, and the output is bridged we have to be really stringent on the matching because there’s no feedback. All the NAP DRs only have one pair of output transistors per channel, so there’s nothing to match against. But otherwise they’re identical so we use the ones that haven’t matched up.”

https://www.the-ear.net/review-hardware/naim-nap-250-dr-power-amplifier

@Richard.Dane @NeilS I have no intention to encourage anyone to try non-naim speaker cables, and indeed I only use Naim speaker cables, but Steve Sells comments in the interview do need some further clarifications.

What does cable tolerant mean? Any cable? or within a certain spec? Steve’s words are quite clear “any cable”

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I think he just means that the newer amps will tolerate a wider range of cables than the older ones. Not all cables.

Regards
Neil.

From what I recall when discussing this, it just means that the current power amps are more tolerant of different cables than the older amps. This would encompass the majority of speaker cables, although “mad” cables - of very high capacitance and low inductance - are still off the table. However, for best performance, Naim’s recommendations still apply.

I read somewhere that back in the day Naim NACA4 and Linn K20 cable is the same cable used for Blackpool illuminations so technically speaking this is also lamp wire :grin:

It all depends to what extent the Zobel network is implemented in the amp output network. Naim traditionally uses the output down stream element to provide the Zobel network, which is done by using the speaker cable and speakers themselves… the offset of instability can be improved by reducing amplifier out put impedance, or other word increasing its Damping Factor at higher frequencies. I understand that in newer designs, especially the higher end amps, parallel output drivers are used, which effectively reduces the amp output impedance… so making the sensitivity to the downstream Zobel network less so.
Other instability aspects can I understand be reduced by adjusting the frequency response characteristics of the negative feedback (where used), and the judicious use of base stopper resistors.

But ultimately an amplifier without an inbuilt Zobel network will need protection in one format or another, and if it relies on the downstream output network then the speaker and cable become a key consideration in that protection.

Important to remember Naim have never said you must use A5. They merely state they believe it gives the best results and that certain high capacitance cables can cause instability/damage.

They both provide the A5 specs for customers to make their own choice and are perfectly happy to give a thumbs up or down if you ask their service dep wether a specific non Naim cable is okay with a specific Naim amp. I don’t think you can get fairer than that.

A few manufacturers test their cables with Naim in the design phase (Atlas for example). Your options are far from limited. And if there is concern… well there’s always A5 which everyone knows works.

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