NVA amps

Richard,

I'm interested in trying a cermet pot in my current pre.
Currently have an Alps Blue in there. Can you recommend a good cermet replacememt?
RS have Bourns and Vishay.

Secondly, I use LS1 and run it with a light twist - is that recommended as you don't supply and usage instructions with the cable.

 

For best results use a 100k linear pot with law faking resistors.

A Vishay/Sfernice P11 or Bourns 81 series is good if you can find them in dual gang.

Paul.

 

No twist, the whole point of the cable is not to twist.

As far as I know Sfernice (French company) has been bought out by Vishay (who are / were Sfernices UK distributor), and it looks like Bourne may have been as well. It is very difficult to get any sense out of Vishay. They seem not to want to communicate and tend to be rude and dismissive. Sfernice if you can contact them direct, as I had to do in the old days are very friendly and helpfull, but generally had a 6 month delivery time !!!!!!!

The Bourne cermets were not very good in the past but now I think they are manufacturing the Sfernice design to cut down lead times for that design.

RS listing them obviously helps if they ever have any stock, but they run out very quickly. I think RS have a delivery coming in this month as I have put an order in for spares for repair of old units. I have found a new pot but I am keeping the source secret as I don't want the same situation that occured with Sfernice. After singing their praises in the late 80's and 90's all of a sudden everyone and their grandmother had "discovered" them. Stock problems became even worse.

Richard

 

Many thanks Paul.

 

Thanks Richard,

<lifts carpets - huff - puff - expletive - expletive - untwists cables.....>

Seriousely though, isn't running them with no twist going to give horribly high inductance due to the conductor spacing?
Also getting both channels to have the same electrical characteristics is going to be mighty difficult.

Just interested - not being critical of your thinking in any way.

 

Really you should only think of using LS1 or LS3 with nva amps, I cannot recommend any other speaker cables as I don't know them. In the past I had a list of compatable cables, but I know nothing of the current crop. Complete disinterest in things Hi-Fi for the last 6 years, apart from listening to music on my own gear I am afraid.

Don't bother with any questions about compatability with computers or AV gear. It is not my thing. The only answer you will get from me is suck it and see, and if you don't like send it back for a refund. The list of what we have / are making / are planning at this moment (time changes all things) to make, are on the nva listing pages at ebay.

Richard

 

I think you misunderstand. Why would you want your polarities to communicate. Anyway my advice stands, I really don't think it will make any or extremely little difference, as the result of spacing is exponential. There are far more important factors such as dielectric properties and other considerations in design differences between cables. It is only in very very close proximity that odd things happen.

Richard

 

I was thinking of stuff like DNM or Naim cable where the conductor spacing (10mm+) gives low capacitance but high inductance.
I would strongly suggest including a sheet of A4 with usage instructions with the cables. Selling it as four mono lengths leaves users liable to use the cables incorrectly.

I've been of the view for many years now that cable sound is purely down to the different combination of L,C & R - and nowt else so I like to know what I'm getting when I buy a cable.

 

The cables cannot be used incorrectly. I only replied as one of the main reasons the cable is as it is - is for there not to be any twist - internally or externally. If I thought there was something of any consequence to talk about, I would have - I do not. Ask DNM or Naim why. I think I know why and it is more to do with strand twisting than cable spacing. Two sets of twistings then react more to spacing. NVA cable is 7 or 14 seperately insulated solid cores run in parallel. The nva cable is bullet proof in real terms, do what you want with it, even lightly twist it. As I said I think little or no difference unless you put it in a drill chuck and twist it to a ridiculous extent. Inductance is misunderstood, it only becomes of importance in context with other parameters. Beyond a certain distance apart there is no effect or consequence. The spacing is not to create a closeness but to create a distance.

If there is nothing to write then why write it.

Richard

 

Ok Richard, it's your cable, and I like the sound of it, but have to dissagree with just about everything in the above post. FWIW, DNM and Naim cables have similar spacing, L&C and yet the former is solid core.
However, this isn't the thread to expand on it and I suspect from your previous answer that you feel it unnecessary to do so.

 

Having used both the 'black box' and statement series kit in the past, I am really pleased to see that NVA is available again and can fully understand Richard's sales methodology.

Hope all goes well for you Richard.

ps A nice (top loading) CD transport in the small form case..........

 

The major problem is a little knowledge is a dangerous thing. Elecromagnetic force seems to be little understood in the Hi-Fi world apart from by electronic design engineers, and most of those have less knowledge than most of you about how that effects the sound. It is like magnetism, gravity, light, sound, feeling, emotion. The movement is either to create a disharmony or to balance an existing one (create harmony). Energy is always looking for the centre (balance), which is why it expresses as an oscilation / vibration / sine wave. The only thing that carries nothing is pure DC. So beyond a certain difference there is no difference. We play with our little differences and theories in Hi-Fi. For what reason, to create an audible difference, or to compensate for a design (or lack of ) consideration. Which of these is this spacing on the cable to justify.

I tell you what, you take one of your Naim or DNM cables and cut it down the miidle and seperate the two bits of cable a foot or two apart and listen again, if you hear any difference (not psychosomatic) or you damage the amp, or if it even gets warmer (the first sign of stress) I will eat my hat publically. Tape the cables next to each other without the spacing and if you don't get an effect I will eat my hat. You have it conceptually arse about face I am afraid.

What is the 10mm for, what is the potential expansion and contraction of the wave in the cable, how far out is its electromagnetic influence. That is the point 10mm or a million miles - no real difference. A couple of millemeters or less and the cables *talk* to each other in a *induced* conversation What are they saying "hey I am different to you I want to be the same". Why do you think a transformer does what it does. Do you think it would still do it if you spaced the coils 10mm apart? not at the voltages we work with.

Capacitance and inductance are but the Yin and Yang of electromagnetic force.

Will I have to bin this post as well! - ho hum.

Richard

 

Blimey........chill!

I simply suggested that you include a few words of guidance for your customers. Most speaker cables come as figure 8, bumbell or twisted pair so when I bought your LS1 I twisted it. Several posts back you said don't twist it, then you said it makes no difference. Either it does make a difference (clearly it does) or you've invented magic cables. Interesting.

You said that a little knowlwdge is a dangerous thing, well no knowledge at all is plain daft. I simply suggest that you provide some to your customers.

 

You obviously haven't understood anything I have said, so it is better to end the conversation.

Richard

 

!!

Oh I do understand it - really, its just that this is a public forum for enthusiasts to exchange ideas and discuss audio related issues. I question you and suggest that you include a simple piece of guidance with your cables and you throw your toys out of the pram.

For a better understanding of what is important in cable design I'd suggest you start here with this AES paper:

http://www.luacheia.com/misc_images/cableInteractions.pdf

You won't find much on Yin and Yang, or natural harmony but it handles the basics well.

 

Here is another perfect example why the conversation should end. I have no toys in my pram to throw out, and nothing I have said is personal or confrontational. It is your misunderstanding. I have explained why I differ in opinion. I have expressed the view that you are parroting little understood promotional design characteristics of other products and using those to judge my products. Those statements of yours are then invalid and I have tried to explain why.

There is no need for a *paper* as there is nothing to do. You took it on yourself to make a decision to do something that someone else had recomended for their product, not mine. I simply said what you had done goes against the design principle of the cable, so in principle I didn't agree with it, but I did not believe you had done it enough to cause a problem or make a difference, Do you understand now?

I have been trying to explain that what I am working with now (not when LS1 was developed) involves energetic concepts that go far further than just audio subjective assessment. Quoting or linking to AES papers will not change things associated with that. Show me where those intellectual masturbation things influence the real world and I will listen. Objectivism is simplistic intellectualisation, satisfying the frontal lobe. Music and musical reproduction is far deeper than that and the way the human body reacts to and passes energetic stimilii is analogous in many ways to the way Hi-Fi reproduces it. It is like a primitive robot of the way we utilise it internally, but it is still largely doing the job, why? I link you to a post earlier on another topic where I refer to the man with a hearing aid who was finding musical differences as applicable and as easily as the fully hearing, but from a lower base point. Write an AES paper about that!

As it stands there is no objective or subjective reason to change my cable, tell people to twist it, or not as the case may be. Or to lose my temper or throw toys out my pram. So many threads and posts on discussion lists lead to these conclusions and confusions as you have no ability to read my energy as you would have if this conversation was face to face, so you misunderstand to facilitate your prerogative. In fact apart from the fact that it is obvious to me that you haven't understood me, but believe you have, is the only frustration in this conversation, and the only reason I said to end it. If there was communication I would enjoy it, otherwise what is the point of doing it!

Peace! time for bed.

Richard

PS I wrote this years ago but it is still largely valid on the objective side.

THE GENESIS REPORT: INDUSTRY AND EXPERT FEEDBACK

By publishing The Genesis Report, QED has returned the Great Cable Debate to its scientific roots. CYBERFi asked a number of leading amplifier manufacturers for their response to the conclusions of QED's investigation.

Representatives from Naim, NVA and LFD join cables expert Malcolm Hawksford of Essex University to cast a critical eye over the new white paper, assessing its findings in the light of their own research

RICHARD DUNN of NVA says:

The report is both right and wrong. In my view high resistance is not the issue. What determines the way that cables affect system performance to a far greater degree is the output impedance of an amplifier. The question of cable inductance, capacitance and resistance has to be considered as an integral part of the amplifier/cable/loudspeaker interfacing equation. Amplifiers such as NVA's, Naim's and Exposure's which do no have a Zobell network on the output, are sensitive to the effects of capacitance and inductance. Transistor amplifiers with Zobell networks or output filtering and valve amplifiers with transformer coupling on their outputs are not so sensitive. If an amplifier has negligible output impedance (ie the damping factor is high), the effect of relatively high cable resistance is minimal. Our LS1 cable is a fairly high resistance cable, but our amplifiers have a 0.0065 ohm output impedance, so there are no ill effects.

Cable directionality is a audible phenomenon. Indeed cable performance can vary with even more obscure factors than this. I have found with solid core cable it is possible to create directionality over a period of time. It's as if the cable beds-in when used aligned one way. If you then reverse one of the cables it can sound worse. But if left, it will bed-in once more over a period of time.

I agree that the cable dielectric is more important than the conductor purity. However if you coat a copper cable in silver, the change will affect performance as much as any change in dielectric material. The dielectric is know to affect cable capacitance more than any other factor with the exception of using Litz construction. Output transformers and Zobell networks hide the deficiencies of cables. So the danger is the wrong cable solution can be prescribed. High capacitance cables apply a cure to the bad audible effects of Zobell networks and output transformers, but as in medicine, it would be much preferable to not have the condition in the first place!

I welcome QED's report. The use of scientific techniques to help evaluate cable is to be applauded. My concern is whether the tests have been carried out in sufficient depth. Individual manufacturers are usually the best source of recommendation for suitable cable to partner their products. Ultimately the big issues concerning cable are the same as those affecting systems. It's all about interfaces from the start of the recording chain to the final link when playing back through a hi-fi system.

 

Very nice posts Richard... :beer:

It is a shame that one cannot speak seriously on any forums, it always ends the same way... :SLEEP:

 

Richard

Many years ago I bought some of your amps, which did not initially work well. You sorted them out and as a peace offering brought me some LS1 cable, to replace the Naim cable that I was using. That experience stands even today as the most obvious demonstration of cable synergy - you knew your stuff and demonstrated the effect to me. Anyone would have to be terminally cloth-eared to not hear the difference. I have always clung to the notion that there is a 'Black Art' to audio design, and you proved it. I, like many (I suspect) have no interest in 'understanding' oe 'explaining' everything and the subjectivist approach is therefore fine by me. Please carry on Richard!

BTW, did you cure yourself of old Alfas?

Cheers

S

 

What's high resistance? I've measured the loop DCR of DNM Reson loudspeaker cable and found this to be around 0.15 ohms per meter. Sufficient to cause audible level losses into 4 ohm loads (loudspeaker minima impedance) for 3 meters of cable.

High resistance loudspeaker cables are plain daft. But then again, so are a lot of other things. Subjectivism rules? Maybe. I quite liked the DNM cable.

 

Forgive me, but the above was your reply to my simple question. The reply signals to me that twisting your cable is not advised - I merely asked that you explain why and that you communicate this to your customers. As a user of your cables and previously electronics I was keen to understand your thinking. You don't wish to do so and feel it would serve no purpose. Ok

I read the QED report several years ago and feel that some of its findings are sensible. The problem with cable discussions is that we often see unproven nonsense and half baked theories entering the debate when in fact cable 'sound' can often be explained very simply.

Anyway, I wish you well with your venture and I promise to continue using the LS1 until something better comes along