NVA amps

Discussion in 'Hi-Fi and General Audio' started by rockhopper, Jul 5, 2006.

  1. rockhopper

    sideshowbob Trisha

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    Apologies for assuming you'd gone bust Richard, it was such a sudden disappearance I think most people assumed the same. Good to see NVA back in some form, hope it's a success.

    -- Ian
     
    sideshowbob, Jul 5, 2006
    #21
  2. rockhopper

    eisenach

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    What about the speaker cable? How does it compare with other offerings?
     
    eisenach, Jul 5, 2006
    #22
  3. rockhopper

    Richard Dunn

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    I wont comment subjectively as there are many solutions in the cable argument. BUT what is mostly misunderstood is the importance of interface. Just think of the cable as another component in the circuit design, it just happens to be an interface component. AND as such it is load and matching that is the priority.

    I design cable to be a neutral load, non filtering and as wide open as I can make it (the same design criteria applies to the interconnects). This is perfect for NVA amps as they are a simple circuit and no filtering or compensation in the output. Most amplifiers are not! most have at least a zobel network or in the case of valve amps output transformers. Capacitive and inductive output filters. This anomaly is mostly applied in order to get unconditionally stable amplifiers, which bizarrely has created an inverse anomaly of cable designed to compensate for the applied amplifier compensation. Hence the appearance of cable of Litz type design or Goetz. These are fine cables in the right context in the job they are designed to do but give them to an NVA amp and others like them with straight through uncompensated outputs and you will get smoke very quickly and speaker frying voltage rail on the output. The reason - they create a virtual short circuit load at above 30k. A filtered amp is not working up there, but some are. The situation is similar for Naim and Exposure type amps but they are more influenced by the inductive element where as NVA doesn't like the capacitive element. We recently did a version of the cable more suitable for the Naim / Exposure type of design designated LS3.

    So the long and the short of it is like everything else there is no best cable, there is the most appropriate interface.

    NVA cable will never harm an amp, the worst affect is it will make some systems sound a little flat. But the cables were the first items back into production last year and we have only had a couple of sets returned.

    This whole Hi-Fi game is a real can of worms, you change a cable - it is better, so that is now *your* best cable - not necessarily! keep an open mind, solutions are system not component based.

    I have an evening off from teaching so I am indulging myself, it is unlikely I will be a regular here, but I will try to contribute as time and incentive allows.

    Richard
     
    Richard Dunn, Jul 5, 2006
    #23
  4. rockhopper

    JonR

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    Hi Richard,

    A quick question then, if I may, and apologies in advance if it seems like a silly one!

    Could your P50 passive preamp work in conjunction with a Naim NAP200 power amp, such as I use in my system. The speakers I use are Neat Motive 2s by the way.

    Many thanks in advance for any reply.

    Regards,

    Jon
     
    JonR, Jul 5, 2006
    #24
  5. rockhopper

    Richard Dunn

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    Hi Jon

    Yes but whether you like the results or not is another matter. With an active pre amp you have a constant output impedance. With a passive you have a variable output impedance, as the power amp is looking directly at the potentiometer. So again it is interface. Does the power amp reject that load and *load itself* the way an NVA does or does that variable load really affect the frequency characteristics at the input. That is the variable. Really ultimately a power amp should be diesigned for a pre amp not visa versa. So again many variables, one of the most critical being gain. You have to put the extra voltage gain in the power amp that is missing from the pre amp to design for a passive. If you think about designing for a passive, as long as you are not looking at buffer amps around the VC, it is like just putting the cables at a different point in between the gain stages. An amplifier system is just a series of gain stages getting more and more toward current drive as opposed to voltage drive as you progress through the system.

    Again because of load characteristics valve power amps normally benefit from a passive and most transistors amps do, as long as you realise you will lose some power. BUT as most pre power systems are designed to voltage clip at about 6 to 7 o'clock on the VC relative to the design load there is no real disadvantage, in fact you get more control in that situation as clipping comes in latter subjectively. When you have a very skillfully designed system solution as is present in Naim systems you should go carefull in how you interfere with it as it will change the results considerably. Personally I would not use a passive with a Naim, but that is just my gut feel. But to be honest I have never tried nor do I know anyone who has. You can try it yourself and send it back if you don't like, and solve the problem for us and publish the results here.

    Richard
     
    Richard Dunn, Jul 5, 2006
    #25
  6. rockhopper

    RobHolt Moderator

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    The return of NVA electronics is fantastic news. I bought some LS1 speaker cables about 12 months ago and they are still in the system, which is unusual for me as I tend to tinker and swap. I have no intention of replacing them as I simply cannot hear them - they are transparent.

    At the price, that little AP10 personal amp looks a bargain and could be just the thing for users of efficient and easy to drive speakers.
     
    RobHolt, Jul 6, 2006
    #26
  7. rockhopper

    LinearMan

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    That is the most coherent, sanest and well informed & written post I've read on here in a long while.
     
    LinearMan, Jul 6, 2006
    #27
  8. rockhopper

    rockhopper

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    Hi Richard, i've just bought a pair of your interconnects. Looking forward to trying them. I'll post my thoughts here.

    All the best,

    Greg
     
    rockhopper, Jul 6, 2006
    #28
  9. rockhopper

    Effem Cable manufacturer

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    Hi Richard,

    I really can appreciate your thoughts on the industry because I am probably going through the same loop as you I reckon. If you can't beat them join them I say, so I have another project lined up besides cable making for a living. PM me if you want to know what it is.

    You probably may not recall but I used to work alongside Dave Millard at Hi-Fi Consultants in Peterborough back in the 80's and it was always interesting hearing your views back then. Not only did I live within sight of the Tresham Audio factory, I also bought a Tresham pre/power combo with a Tannoy label swinging off them which kept me happy for nigh on 15 years. That was THE best pre/power combo I have ever owned and been kicking myself for the last 3 years since I sold them
    :cry:

    I also bought a set of NVA sound pipes recently and I thought they were very good for the money.

    I would have thought that your spirituality would have given you the strength to lock away the nasty bits of the industry and continue with your lateral thinking about the way things ought to be done and breaking new ground
     
    Effem, Jul 6, 2006
    #29
  10. rockhopper

    Richard Dunn

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    Hi

    The history is that the company was doing well up to 1997, though critical mass made it far more vulnerable to the swings of the market than the likes of Linn and Naim. We never made a £1m turnover which seems to be the point you break through this. We ended up at that point with over 80% of our turnover going to the far east. Then overnight we had the far eastern currency crisis, starting in Korea and spreading throughout the far east in 24 hours. Over night I had 80% of my order book wiped out by email and fax.

    I had developed a fascination for eastern culture and internal arts from going out there so much on business, and realised that this and subjectivist Hi-Fi were far from disconnected. BUT as I have just realised here very few people are ready even now to hear this. The way the body mind and spirit react to the stimulation of music is fundimental in this as we are working with subjective energetic responses. That is the basis behind the subjectivist Hi-Fi movement of the 70's and 80's. Realising this and applying it to audio design just seemed like a natural progression for me in the 70's and is the basis behind the subjective imperitive. There were other great(er) pioneers in this likened by Ivor and Julien and others too numerous to mention, in many ways I believe this was stimulated by the 60's hippy thing :) Anyway my personal interest just broadened as to how you work with this in the human energetic structure (entity) as opposed to how you just stimulate it with music reproduction. So when I had to downside the company in order to cope with my order book being wiped out, I naturally progressed more to what I believed were the fundementals of this and not just the side show of audio emotional stimulation. I was already teaching internal arts but I expanded my school to the point that it was helping pay the running costs at NVA. I seriously thought about making it an internet based company even then, but the systems and infrastucture were not really in. So in the end I just closed it. I now find the market is more amenable to this way, and also it seems the market is coming back to real hi-fi away from the audio visual and computer based aberations that have pre-occupied it for 5 years.

    I hope I am still breaking new ground, but you must realise a lot of it will still seem quite loopy, as the subjectivist movement seemed in the 1970's, and yet that has now largely become the accepted hierachy. Also so much of the subjectivist imperitive can be applied in so many other directions in life that are part of our energetic stimulation. They are mostly to do with the senses, so think of the development of food an wine appreciation, subjectivism has moved there, and there are many other areas it can and has moved into.

    For me I am exploring the fundimental nature of this process within the human body and psychi, and it is a fascinating process. Now I am finding the Hi-Fi market has changed again and my original work is coming back into validity, and there is now a vehicle in the internet to progress with it again. In audio terms how much more I will progress it is a moot point, and my last post that I had to take down due to idiot comments has convinced me I shouldn't dwell on it too much publically. I do not wish to become the target of the vexed Dinosaurs as we saw in the audio industry in the 70's and 80's. I am now into a peacefull life and pursuing my own peculiarities :D

    Richard
     
    Richard Dunn, Jul 6, 2006
    #30
  11. rockhopper

    spev

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    Richard, If I had some spare cash knocking about I'd buy some of your amps based on the outlook expressed in your posts in this thread alone - I've looked through the ebay listings a few times wondering about the NVA amps!
     
    spev, Jul 7, 2006
    #31
  12. rockhopper

    Richard Dunn

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    There has been far too much of putting people up on pedestals in the Hi-Fi industry. Masturbating designers ego's became de rigueur in the "good old days":) . I just had a private email asking if he "had the honour of addressing the famous Richard Dunn of NVA" - I was rude!

    Why did this develop? audio designer are not film stars or pop idols (though I have at times thought some may have wished they were :D ).

    Don't buy anything on what I say, try and buy it, or not, on what I do.

    Richard
     
    Richard Dunn, Jul 7, 2006
    #32
  13. rockhopper

    spev

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    and I quote:

    If you buy hi-fi equipment on the basis of what a manufacturer says about himself (including us!) you really do deserve what you get.

    ommmmm :)
     
    spev, Jul 7, 2006
    #33
  14. rockhopper

    rockhopper

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    Hi Richard,

    any idea when you'll be sending out my interconnects?

    Thanks a lot.

    Greg
     
    rockhopper, Jul 7, 2006
    #34
  15. rockhopper

    Richard Dunn

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    How do I know who you are and which are your interconnects? I have no client called Rockhopper :)

    Anyway all outstanding cables are going today, so you must be amoungst them.

    I do think things like this are off topic and should be PM.

    Richard
     
    Richard Dunn, Jul 7, 2006
    #35
  16. rockhopper

    rockhopper

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    Because I explained earlier in thread that I had just bought a pair of interconnects,

    "Hi Richard, i've just bought a pair of your interconnects. Looking forward to trying them. I'll post my thoughts here.

    All the best,

    Greg"

    i.e. the name I used when communicating via eBay.

    Sorry for the confusion.
     
    rockhopper, Jul 7, 2006
    #36
  17. rockhopper

    quickie

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    Greg,

    Check out the archives/reviews section on the old NVA site for some write ups.

    http://nva.sclnz.com/

    Having owned/used pretty much most of the black box range over the last 15 years of so,I've yet to find anything that really out performs it pound for pound.............

    Paul.
     
    quickie, Jul 8, 2006
    #37
  18. rockhopper

    Richard Dunn

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    Sorry to you Greg, I shouldn't have been ratty.

    Richard
     
    Richard Dunn, Jul 9, 2006
    #38
  19. rockhopper

    Rory satisfied

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    hi Richard i know your amps were a little 'fussy' about what speaker cables could be used with them. I was really impressed with a AP10 driving some QLN 111s at Alastair (Signals) a while back and wondered if you had anything (high end) that was processor compatible i.e. had fixed level gains that weren't controlled by the volume pot.

    Would Electrofluidics Monolith 2020 be compatible with the NVA stuff? My friend also bought a passive pre (not one of your current ones- a P70 or P90 i think) and is well chuffed with it!
     
    Rory, Jul 9, 2006
    #39
  20. rockhopper

    nixon_fiend

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    the monoflubby wire is re-badged goertz alpha-core..

    I believe it is very high cap. so about as far from LS1 as you're going to get.

    Y'know, i don't think that'd be such a great idea :micro:

    Mr. Dunn, I hope the D/A converter is progressing well, inexpensive outboard dacs a la shek-dac are very popular around here.. I'm sure you'd find many customers, including yours truly
     
    nixon_fiend, Jul 9, 2006
    #40
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