Technical speaker cable advice

[Chris81]

Good morning,
I'm looking for some technical help related to cables (no random namedropping advices please).
If I understood it right, older Naim amplifiers need low capacitance and high inductance cables to work stable.

How do I know if a cable has a low capacitance and high inductance, which numbers/values are low/midfield/high?

Which technical kind of cable is good for using it with valve amplifiers?

Thank you very much and have a nice day.

 

[Werner]

How do I know if a cable has a low capacitance and high inductance

You can often see this. Widely-spaced conductors = low C, high L. Conductors close to each other, or twisted/woven = low L, high C.

 

[toprepairman]

Oh no, here we go again....

 

[RJohan]

I have regulary used my Naim Nait 2 with cheap 'what ever' cables. No problems. No need to worry.

The whole discussion comes from some early 'audiophile' cables in the mid 1970's that was designed to have low inductance and therefore also had high capacitance. They killed a number of amps, not just Naim. Are such beasts still made?

 

[Del monaco]

I used my Olive 82/180 with Kimber 8TC. For over 2 years, no problems whatsoever.

 

[Chris81]

Please don't start a general discussion about (older) Naim amplifiers or matching cables, that isn't what I'm looking for.
My question for an advice is only related to these both questions.

How do I know if a cable has a low capacitance and high inductance, which numbers/values are low/midfield/high?

Which technical kind of cable is good for using it with valve amplifiers?

Thank you very much for respecting that.

 

[Tony L]

Which technical kind of cable is good for using it with valve amplifiers?

Valve amps have no special cable requirements. You can choose pretty much anything you like the look of, including NAC A5 if that is what you have knocking around. I’d just go for good thick copper of a reputable brand if you are looking to buy new, e.g. Mogami, Van Damme, Supra etc, but that would be my recommendation for any amp. The only amps that are fussy tend to be hair-shirt UK solid state and lack output stage stability if used outside a recommended cable type, e.g. Naim, NVA etc.

 

[John Phillips]

... How do I know if a cable has a low capacitance and high inductance, which numbers/values are low/midfield/high? ...

@Werner has provided the correct "rule of thumb" in his "Widely-spaced conductors = low C, high L. Conductors close to each other, or twisted/woven = low L, high C." (C = Capacitance and L = Inductance - it's conventional in engineering to use L for inductance).

In most real-world situations you don't really need to know more than this to choose a cable. Natural physical laws constrain any realistic cable's characteristics within a fairly narrow band.

But if you really want to attach numbers and see what range to expect, see figure 1 on @Jim Audiomisc's page here. The green dots represent measurements on about 30 different cables, each plotted against its inductance (micro-Henries per metre) on the vertical axis and its capacitance (pico-Farads per metre) on the horizontal axis.

The red square on the extreme right is the woven cable from 1979 with high capacitance and low inductance (as @Werner wrote). And on the extreme left you have cables, also as @Werner wrote, that have widely-spaced conductors so low capacitance and high inductance. For any individual cable sometimes the supplier will provide its characteristics, and its specific place in the L-C spectrum can be identified.

And I am sure @Tony L is correct re valve amplifiers not being sensitive to cable choice.

 

[Gervais Cote]

Cable as mentioned in post no. 2, 3.5 meter long as a minimum is all you need to know for a Naim amp.
No name dropping so either black, white, grey or transparent as long as the cross section is bone-like.
My comments are based on several trials and errors with my numerous Naim amps and integrated and I always prefer relying to my ears than technical specs.

 

[Chris81]

@Tony L @John Phillips : Thank you very much. The link was helpful (I haven't finished reading it).

Does the cable type alter the frequency response or interact differently with a valve amplifier?

What are the advantages of the different types of cables (low capacitance and high inductance vs. high capacitance and low inductance).

@Gervais Cote : Thank you but again, that isn't what I'm looking for because I know that.
I don't even have a Naim amplifier. I have a Croft Epoch Elite with a 5 R Elite. I'm only interested in the technical differences like this from the link...

"Unfortunately, high capacitance can cause instability with some power amplifier designs, sometimes prompting oscillations at ultrasonic frequencies.and in which case which type of cable makes more sense."


...and an answer to this question:
"How do I know if a cable has a low capacitance and high inductance, which numbers/values are low/midfield/high?"

 

[Tony L]

"Unfortunately, high capacitance can cause instability with some power amplifier designs, sometimes prompting oscillations at ultrasonic frequencies.and in which case which type of cable makes more sense."

To my knowledge it is only early Naim and a few real hair-shirt solid state amps such as NVA, DNM etc that suffer from oscillation, so if you are outside of that tiny ecosystem then you can ignore it and consider anything that is marketed as a speaker cable.

I’d not over-think it personally. I’ve sat in on more cable dems than anyone sane should ever do, and whilst I can certainly hear subjective differences between the outliers (e.g. Naim vs. Kimber or DNM), the vast majority of speaker cable occupies a sensible middle-ground and I have found myself the happiest with fairly fat standard copper cables such as Mogami, Supra Classic, Van Damme etc. I avoid thin, I avoid flat, and I avoid fancy materials or construction as they all tend to push things to one or other extreme of the bell-curve. Basically I don’t want my cables to define the system sound so I just go for what I view as the centre-ground electrically, which is a typical studio style cable made of good quality thick copper. The only ‘fancy’ cable I have is Chord Rumour II on the JR149s and it is absolutely not what I would choose (way too thin IMHO). I only use it as it fits through the rubber grommet on the back!

PS My controversial statement of the thread is: ‘if you can identify a speaker cable by its sonic traits then it is an outlier and is best avoided!’. I’ll just leave that one hanging there and walk away….

 

[John Phillips]

@Tony L @John Phillips : Thank you very much. The link was helpful (I haven't finished reading it).

Does the cable type alter the frequency response or interact differently with a valve amplifier?

What are the advantages of the different types of cables (low capacitance and high inductance vs. high capacitance and low inductance). ...

On cable type, @Tony L is correct according to my PoV. There are a very few exceptional cases - loudspeakers with extreme impedance curves - where you might, for example, need very low inductance cables to avoid audible treble droop. In these few cases actually siting monobloc power amplifiers close to the loudspeaker might be a better fix than finding outlier loudspeaker cables to compensate for arguably crazy loudspeaker design.

Regarding interaction with a valve amplifier, I am not aware of anything to worry about regarding cables. However, with valve amplifiers you can sometimes get an interaction between the amplifier's output impedance (typically higher than solid-state) and the loudspeaker's bass-end non-constant impedance curve dipping very low. The cable is blameless here but bass frequency response can sometimes get changed in subtle but audible ways.

On advantages and disadvantages broadly, there's not broad truth IMHO. I know others may dispute this. But for me, it's only, as @Tony L writes, the few extreme cases (as I wrote above) where there might be some advantage to be found in particular types of cable.

 

[Craig B]

You can often see this. Widely-spaced conductors = low C, high L. Conductors close to each other, or twisted/woven = low L, high C.

I'd be inclined to separate 'twisted' vs. 'woven' (no pun intended), as AIUI twisting ± pairs of conductors increases inductance in otherwise low capacitance cables, whereas, woven (braided?) will dramatically increase capacitance.

 

[Chris81]

Thank you both again. For safety, I'm not going to buy fancy, expansive cables. Currently I'm using DNM but as mention by @Arkless Electronics that it does alter the sound I'm curious to try out a conventional (twisted) cable like the van Damme (I have used it in the past) again. Because I moved my setup from my tiny "only listening room" into our living room I recognize that the DNMs lean bass and brighter sound doesn't work anymore to my ears.

I asked for the difference, because I don't like to swap cables and I was looking for cable that I can use with a valve amplifier without changing the sound as much as the DNM does but also is working with stuff like oder Naim and Exposure amps, if I want to use one of them.

I have had an Exposure Dual IV regulated in the past which started to swing at higher volume with the van Damme cable, so I sold it and bought an Exposure cable which I traded later against the DNM out of curiosity. I preferred it with several speakers in the past with different amps in another flat but now I think I need another cable again.

Because I currently own the Croft 5 R Elite (valve) power amplifier I asked what so consider if there is any countable interacting with different kind of cables like the Exposure in the past.

 

[Arkless Electronics]

Cable doesn't have a sound. In the rare cases that it influences the sound it is due to the way the speaker interacts with the electrical characteristics of the cable. In the case of the thin ribbon DNM cable it has considerable resistance. This adds to the output impedance of the amplifier (which is usually negligibly low in the case of most SS amps) and reduces the damping factor, allowing the speakers impedance curve to interact with the total source impedance it see's and acting as a speaker dependent tone control, ie if the speaker happens to dip to say 5 Ohms around 2KHz then there will slightly reduced output at that frequency as more of the output is lost in the cables resistance than at frequencies where the speaker is 8 Ohm.

If a cable has high inductance then this has a frequency dependent effect. The higher the frequency the higher the impedance of the cable. In most circumstances this will be negligible and can be ignored. If a speaker has a major impedance drop at high frequencies (pretty rare) then this will cause a treble drop. ELS's can drop to 2 Ohms or so in some cases up at around 20KHz and this could then interact with high inductance cable to reduce top end. A few speakers have HF correcting crossovers with a major impedance dip at high frequencies but not many... original SL6 is about the only one that springs to mind but there will surely be others.
The voice coil of the tweeter has inductance and so the impedance of the tweeter is generally rising at the high end anyway and lessening/removing any risk of this happening. A few outliers like Maggies are pretty much a resistive load and in this case quite a low one at 3.5 Ohms and so cable inductance could have some effect.

Capacitance is pretty low even for high capacitance cables and the only effect is possible interaction with some badly designed amplifiers which are not unconditionally stable which could cause them to become unstable ie they oscillate, sometimes with fatal consequences for amplifier and/or speaker in extreme cases. In such cases the capacitance would also cause the amplifier to boost treble.... but only at frequencies bats could appreciate!
Note the cable does not boost treble. Cables have no sound. It is the capacitance making the amplifier boost treble! It would be VERY unlikely for this to happen at a frequency below say 30KHz so as I say for bats only.... and only with dodgy designed amps anyway.

Although the construction of a cable will effect the above parameters they are all directly proportional to the length of the cable. In the vast majority of circumstances only the resistance will have any effect.

TLDR; Use short lengths of pretty thick cable and all the above cable characteristics will be so microscopic that they will have no effect at all on sound and all cables will sound the same, ie totally transparent. ie if fairly short and thick then even placing monoblocks on pedestals behind each speaker and using only 6" of speaker cable would make no discernible further improvement.
Ideally place power amp between speakers or monoblocks next to each speaker and use longer interconnects.
Aesthetes concerned about hiding speaker cables and using say 12 - 15m lengths hidden in walls, in ceiling, under floor, will, perversely, need the thickest most welding cable like speaker cable to ameliorate the length...

 

[Chris81]

Thank you very much for the explanation, that exactly was what I was looking for.

 

[Craig B]

I asked for the difference, because I don't like to swap cables and I was looking for cable that I can use with a valve amplifier without changing the sound as much as the DNM does but also is working with stuff like oder Naim and Exposure amps, if I want to use one of them.

This narrows things down nicely. Your cheapest, easiest to live with (very flexible) option will be Linn K20.

Electrically, this is the same as original Naim NACA4, as both are essentially BICC outdoor lighting cable, and like all such cables, worth no more than their weight in copper. The spacing web between was a happy accident, as the original design intention was such that this outdoor cable could be easily nailed to masts round the village fête/carnival site/military encampment.

If you believe that you may eventually try Naim or classic Exposure amps down the road then best to go for 3.5m lengths per side as minimum (circa 20m as maximum).

 

[Craig B]

Cable doesn't have a sound. In the rare cases that it influences the sound it is due to the way the speaker interacts with the electrical characteristics of the cable. In the case of the thin ribbon DNM cable it has considerable resistance. This adds to the output impedance of the amplifier (which is usually negligibly low in the case of most SS amps) and reduces the damping factor, allowing the speakers impedance curve to interact with the total source impedance it see's and acting as a speaker dependent tone control, ie if the speaker happens to dip to say 5 Ohms around 2KHz then there will slightly reduced output at that frequency as more of the output is lost in the cables resistance than at frequencies where the speaker is 8 Ohm.

If a cable has high inductance then this has a frequency dependent effect. The higher the frequency the higher the impedance of the cable. In most circumstances this will be negligible and can be ignored. If a speaker has a major impedance drop at high frequencies (pretty rare) then this will cause a treble drop. ELS's can drop to 2 Ohms or so in some cases up at around 20KHz and this could then interact with high inductance cable to reduce top end. A few speakers have HF correcting crossovers with a major impedance dip at high frequencies but not many... original SL6 is about the only one that springs to mind but there will surely be others.
The voice coil of the tweeter has inductance and so the impedance of the tweeter is generally rising at the high end anyway and lessening/removing any risk of this happening. A few outliers like Maggies are pretty much a resistive load and in this case quite a low one at 3.5 Ohms and so cable inductance could have some effect.

Capacitance is pretty low even for high capacitance cables and the only effect is possible interaction with some badly designed amplifiers which are not unconditionally stable which could cause them to become unstable ie they oscillate, sometimes with fatal consequences for amplifier and/or speaker in extreme cases. In such cases the capacitance would also cause the amplifier to boost treble.... but only at frequencies bats could appreciate!
Note the cable does not boost treble. Cables have no sound. It is the capacitance making the amplifier boost treble! It would be VERY unlikely for this to happen at a frequency below say 30KHz so as I say for bats only.... and only with dodgy designed amps anyway.

Although the construction of a cable will effect the above parameters they are all directly proportional to the length of the cable. In the vast majority of circumstances only the resistance will have any effect.

TLDR; Use short lengths of pretty thick cable and all the above cable characteristics will be so microscopic that they will have no effect at all on sound and all cables will sound the same, ie totally transparent. ie if fairly short and thick then even placing monoblocks on pedestals behind each speaker and using only 6" of speaker cable would make no discernible further improvement.
Ideally place power amp between speakers or monoblocks next to each speaker and use longer interconnects.
Aesthetes concerned about hiding speaker cables and using say 12 - 15m lengths hidden in walls, in ceiling, under floor, will, perversely, need the thickest most welding cable like speaker cable to ameliorate the length...

Your best ever post on the subject, sir!

Clearly explained, whilst simultaneously lacking in vitriol.

Full marks!

 

[peterm]

I agree with the oracle but I must admit to rather enjoying some of the "vitriol"! (usually justified I feel).

 

[peterm]

This narrows things down nicely. Your cheapest, easiest to live with (very flexible) option will be Linn K20.

Electrically, this is the same as original Naim NACA4, as both are essentially BICC outdoor lighting cable, and like all such cables, worth no more than their weight in copper. The spacing web between was a happy accident, as the original design intention was such that this outdoor cable could be easily nailed to masts round the village fête/carnival site/military encampment.

Often quoted and makes a mockery of Julian's quote in an old magazine review (Malcolm Seward's?) that Naim won an out of court settlement from BICC over them selling a cable designed by Naim under the Linn brand name (but in a different colour with a different name on it) and that funded the research into a new cable (NAC A5) that was SO different in material and user friendliness that it beggars belief that Naim "designed" both cables to do the same job.
They must have spent at least 30 minutes looking through cable manufacturer's catalogues!

To paraphrase an old Naim advert, Mr Vereker told exceedingly good stories, and therein, perhaps, lies the secret of his success (not begrudged by the way, well done him I say, rather like James Dyson, an entrepreneur who happened to be in the right place at the right time (in the local pub in Dyson's case after doing the housework earlier and answering another local's question about what he'd been doing all day with the observation that that there must be a better way of extracting dust from a carpet to be told he needed a cyclone like the sawmill down the road used, the rest is history!)