+ Reply to Thread
Page 1 of 3 1 2 3 LastLast
Results 1 to 20 of 48

Thread: Hypex based class D amps

  1. #1
    Join Date
    Nov 2008
    Location
    Jerusalem, Israel
    Posts
    89
    Rep Power
    14140

    Default Hypex based class D amps

    This was probably asked before.

    Does anyone frequenting this forum use class D amps? which kind? are you happy?

    I just bit the bullet and ordered a pair of Nord Acoustics monoblocks. These output 400w into 8 ohm and are based on a Hypex module very similar to the one used in NAD M22.

    What's special is he has built his own input buffer and offers a choice of op-amps (that can be changed if you like, like tube rolling...)

    I figured if I dip my foot in might as well dive all the way and bought his top of the range amps. They also come in a single stereo box but I figured what the hell pay for some bling. Even though really it's another 100 quid for an extra case.

    Dying to try them out and from all the buzz I'd actually be disappointed if my Crimson monos are better.

    Anyone here using them or similar?

  2. #2
    Join Date
    Feb 2008
    Location
    Carmarthenshire, West Wales.
    Posts
    1,008
    Rep Power
    155401

    Default

    Oh dear I thought you would!

    You don't need all that power, I guess it'll never go anywhere near there in normal use.

    What you do need are sensitive speakers so just a few Watts will do the trick.

    John R.
    Last edited by John R; 27th April 2017 at 19:57.

  3. #3
    Join Date
    Nov 2008
    Location
    Jerusalem, Israel
    Posts
    89
    Rep Power
    14140

    Default

    I had to give 'em a go not due to their power but because they're supposed to sound good. Mind you my Royd Edens (what the Crimson 100W monos drove for most of their use) also do not need more than a 25W amp. But the fact remains that when I compared the 50W stereo power amp to the 100W monos I did hear a very real improvement.

    So far the hype around the Nords is not "they're really good for hard-to-drive speakers" but just that they're good and giant killers...

    I don't think the power requirements of my current Royd Doublet speakers are significantly higher than the Edens, but the Crimson amps do get warmer when playing for a long while or at high volume.

    John here saved me from spending some valuable earth pounds, I owe him a beer - or 5!

  4. #4
    Join Date
    Feb 2008
    Location
    Carmarthenshire, West Wales.
    Posts
    1,008
    Rep Power
    155401

    Default

    Heh heh. One day eh?

    John R.

  5. #5
    Join Date
    Jun 2007
    Location
    Birmingham
    Posts
    11,004
    Rep Power
    1792657

    Default

    I can taste the testosterone from here. POWER, GRRRRR!

  6. #6

    Default

    Quote Originally Posted by John R View Post
    Oh dear I thought you would!

    You don't need all that power, I guess it'll never go anywhere near there in normal use.

    What you do need are sensitive speakers so just a few Watts will do the trick.

    John R.
    the problem with trying to use sensitive speakers is that you may not like the sound they produce,at least if you have an amp with power(which you may never ever need)you can look for speakers on sound quality alone rather than worrying if your amp is man enough to drive them

  7. #7
    Join Date
    Nov 2008
    Location
    Jerusalem, Israel
    Posts
    89
    Rep Power
    14140

    Default

    Quote Originally Posted by steve195527 View Post
    the problem with trying to use sensitive speakers is that you may not like the sound they produce,at least if you have an amp with power(which you may never ever need)you can look for speakers on sound quality alone rather than worrying if your amp is man enough to drive them
    My speakers are, I think, 87dB. Not too sensitive but certainly not hard to drive.

    I also use the system most of the time on a low or low-ish level. I bought the Nords on the strength of people (several) saying they don't sound like anything and really let the source through.

    I have just recently changed my speakers and don't think I will do so in the near future. I think my 100wpc class A/B amp is strong enough to drive most speakers that I personally would use. Lack of power was never my reasoning in buying, nor was saving electricity or lowering the temperature in my living room. I did not buy Class D now because it's a compromise but rather because I am curious to see what it can do. My gut tells me that in 3-4 years all major companies will move in that direction. Some have already started.

  8. #8

    Default

    Quote Originally Posted by ahabec View Post
    My speakers are, I think, 87dB. Not too sensitive but certainly not hard to drive.

    I also use the system most of the time on a low or low-ish level. I bought the Nords on the strength of people (several) saying they don't sound like anything and really let the source through.

    I have just recently changed my speakers and don't think I will do so in the near future. I think my 100wpc class A/B amp is strong enough to drive most speakers that I personally would use. Lack of power was never my reasoning in buying, nor was saving electricity or lowering the temperature in my living room. I did not buy Class D now because it's a compromise but rather because I am curious to see what it can do. My gut tells me that in 3-4 years all major companies will move in that direction. Some have already started.
    I wasn't meaning that a high power amp or class d is the way to go,just more or less saying it's horses for courses,don't agree that class d will be the way all major companies will go,unless it's just to save money,there are so called next gen amps being brought out on a semi reg basis,always have been for as long as I can remember and some of the old tech always survives:-because its sounds better as a rule,only thing I remember as being a big improvement when released were the vfet amps made by Yamaha(B-1 and B-2)but they proved too expensive in the long run to keep producing when the mos fets were improving at a far lower cost,till this day I have never heard an amp(power amp) make such an improvement to the sound of any system we tried it in as the B-1,but it was very expensive compared to almost anything else at the time

  9. #9
    Join Date
    Sep 2016
    Location
    Rickmansworth
    Posts
    83
    Rep Power
    14066

    Default

    Looking forward to your listening impressions of the Nord amps, and how they compare with your Crimsons

  10. #10
    Join Date
    Nov 2008
    Location
    Jerusalem, Israel
    Posts
    89
    Rep Power
    14140

    Default

    Quote Originally Posted by jy3 View Post
    Looking forward to your listening impressions of the Nord amps, and how they compare with your Crimsons
    It may take as long as a month from now until I get them but I will definitely post my impress here.

  11. #11
    Join Date
    Apr 2008
    Location
    Birmingham, , United Kingdom
    Posts
    362
    Rep Power
    272501

    Default

    I have been using a pair of DIY Hypex NC400's for 18 months plus now. I have an illustrious alternative in my ARC D70 mkII but I have stuck with my Hypex amp into a pair of 90dB efficient dual concentric Tannoys. There is some commentary here about the power produced by these amplifier modules. If I were to say that the power thing is largely irrelevant you may chortle but the thing to note about these amps is they are truly agnostic of what you connect to them down stream. They will get the best from any speaker connected be that 100dB efficient drivers with flat responses, or hard to drive multiple cone speakers with horrible impedance curves. The only thing I have yet to have any experience of is these into electrostatic speakers. They have vanishingly low distortion figures, low noise and are highly efficient. As close to fit and forget as anything I have experience of. What it does is allows you to shape your system using a pre-amp of your choice. Any flavour of valve, solid state or passive will work with sensible matching. You should have no regrets. In fact I think you may be quite impressed.
    Last edited by Cable Monkey; 1st May 2017 at 11:38.

  12. #12
    Join Date
    Nov 2008
    Location
    Jerusalem, Israel
    Posts
    89
    Rep Power
    14140

    Default

    Thanks cable monkey, this is encouraging news. I am really after better sound rather than an amp to drive difficult speakers. On a side note I think there's less cleverness in manufacturing speakers which are wonderful but are a bitch to drive than in making loudspeakers are that can be driven by many types of amps.

    The amps will drive Royd Doublets, 3-driver floor-standers which are not particularly difficult. Interestingly, though, one of the experiments I am curious in doing is in taking the amps (light at 4 kg each) to the house of a friend who has Martin Logan electrostatics. At the time he needed to shop around a lot before settling on a massive 40kg power amp from Bryston. Really ugly and "profesh" looking piece of kit but I suppose it does the job.

  13. #13
    Join Date
    Apr 2008
    Location
    , , United Kingdom
    Posts
    59
    Rep Power
    0

    Default

    I have always been a firm believer in having too much rather than too little power. I have a kind of mental block that if it will not kick out 100watts into less than 4ohm loads I am not really interested in buying.

    There are wonderful sounding lower powered amps as well but I would hate to think if ever I changed my speakers I would be limited to choice by my amp and even worse if I had to change both.

    A pal of mine builds these things (John Young ...Acoustic Imagery) and he raves about them. John has been many years in hifi and previously loved things like my Hafler, Myst and EAR valve amps .. his enthusiasm for these makes me think they must be good .. and if ever I change my old Haflers they will be at the top of my listening list.
    A good earwash may be the cheapest and best upgrade to your system.

  14. #14
    Join Date
    Nov 2008
    Location
    Jerusalem, Israel
    Posts
    89
    Rep Power
    14140

    Default

    Uzzy's post reminded me I promised to write my impressions.

    So the first day was very unlucky. I listened to a couple of songs in my old Crimson amps and the new Nord amps through the Crimson preamp. At some point the two transistors in the preamp burned out, what caused it to emit very low sound and it was unusable. I sent it to be fixed (the transistors have been removed rather than replaced; apparently their whole job is to short the output when the input selector is moved, so that no nasty clicks come out of the speakers; but this is not happening anyway so they were removed and not replaced.

    Since I only had about 2 hours to listen, I didn't form any opinion, but of the little that I did, I was not impressed. The two sets of monoblocks sounded essentially the same or almost the same, except the Crimsons have more gain so per given volume setting they sounded louder.

    When the preamp was away I hooked the new amps to a minidisc deck to serve as a line stage. Since this link in the chain is super-weak this was only a solution to continue listening to music and not to do any critical auditioning. At Linn they would maybe say this doesn't matter because source first, right?

    Finally, the preamp returned and I started really listening deeply.

    It seems at first hearing that the Nords are "weaker" or flatter; not a loudness issue but rather something a bit limping and lacking meat. But upon switching back and fourth between the two amps, the reason of this was revealed:

    On their own, the Crimsons are remarkably transparent, balanced and uncoloured. But after I switch to the Nords on the same piece of music, I notice three things: The Crimsons have superficially heavier bass, but this is rather because it is less defined and more boomy. I would almost characterize the difference in bass reproduction as similar to the difference between pre- and post-cirkus bearings on an LP12, only less pronounced. With the Nord amps, the bass is very tightly controlled, with deep bass notes having a crystal-clear beginning and ending.

    By the way, at this point I will note that on no occasion did the Nords sound unnatural in any way. Also, remember: the two amps are playing through the Crimson preamp, which is apparently not the finest, so it may holding both sets of amps back (I have read of Crimson owners substituting the company's own preamp for something else).

    So the bass definition was the first thing; the next thing is (again - this only becomes apparent after moving from the Crimson to the Nord) that the Crimson seems to have two "humps" in the frequency response, one in the lower midrange and one in the mid-high trebles. While these humps (not measured, just my subjective impression) make the music exciting, they also make it less natural, and in louder volumes, the higher "hump" sometimes makes the high notes fatiguing.

    While at first hearing the Nord sounded less lively to me, now, after listening to a certain piece on the Crimsons, then on the Nords, there's a moment of "Oh, so that's how it sounded when recorded" or "without the equalizer".

    Why then was I disappointed? Well, I think that what happened is similar to what happened when I bought a Dynavector phono stage. Ever since my local dealer passed away (sad story, he was young) I have been buying hifi blind, without auditioning. Crazy, I know, but circumstances are such that I cannot do otherwise. When I bought the Dynavector, I was expecting to be floored by its performance. Instead, it was better, but not earth shatteringly so. Similarly, the Nords are (I think, still not 100% sure) better than the Crimsons, but it's not like they wipe the floor with them.

    The simple fact is that the Crimsons, when sold in the early 2000s, were a huge bargain. Today the company jacked the prices way, way up, and I think now they may have more competition. The preamp that I have cost 450 quid when new. The new one costs 5400! The monoblocks sold for less than a 1000 quid at the time, while the current model costs about 4500. I am almost certain that the power amps are not hugely different than the old generation. The new preamp is something else, all SMD and with no moving parts and apparently very good.

    ANYWAY, I have a NVA passive preamp coming soon and I hope this will throw the differences into even sharper relief.

    When the preamp was away, I also listened a bit through a late 1990s Rega Elex I have recently purchased to give as a gift to my sister. I must say I was underwhelmed, but then I was comparing it to gear several rungs on the ladder higher, not just one.

    If you've read this far you might as well reply, if you have anything to say... I will post again once I have finalized my impressions and have a verdict. The question now is this: There is a difference, yes. Is it worth 2000 pounds?

  15. #15
    Join Date
    Apr 2008
    Location
    , , United Kingdom
    Posts
    59
    Rep Power
    0

    Default

    Quote Originally Posted by ahabec View Post
    Uzzy's post reminded me I promised to write my impressions.

    So the first day was very unlucky. I listened to a couple of songs in my old Crimson amps and the new Nord amps through the Crimson preamp. At some point the two transistors in the preamp burned out, what caused it to emit very low sound and it was unusable. I sent it to be fixed (the transistors have been removed rather than replaced; apparently their whole job is to short the output when the input selector is moved, so that no nasty clicks come out of the speakers; but this is not happening anyway so they were removed and not replaced.

    Since I only had about 2 hours to listen, I didn't form any opinion, but of the little that I did, I was not impressed. The two sets of monoblocks sounded essentially the same or almost the same, except the Crimsons have more gain so per given volume setting they sounded louder.

    When the preamp was away I hooked the new amps to a minidisc deck to serve as a line stage. Since this link in the chain is super-weak this was only a solution to continue listening to music and not to do any critical auditioning. At Linn they would maybe say this doesn't matter because source first, right?

    Finally, the preamp returned and I started really listening deeply.

    It seems at first hearing that the Nords are "weaker" or flatter; not a loudness issue but rather something a bit limping and lacking meat. But upon switching back and fourth between the two amps, the reason of this was revealed:

    On their own, the Crimsons are remarkably transparent, balanced and uncoloured. But after I switch to the Nords on the same piece of music, I notice three things: The Crimsons have superficially heavier bass, but this is rather because it is less defined and more boomy. I would almost characterize the difference in bass reproduction as similar to the difference between pre- and post-cirkus bearings on an LP12, only less pronounced. With the Nord amps, the bass is very tightly controlled, with deep bass notes having a crystal-clear beginning and ending.

    By the way, at this point I will note that on no occasion did the Nords sound unnatural in any way. Also, remember: the two amps are playing through the Crimson preamp, which is apparently not the finest, so it may holding both sets of amps back (I have read of Crimson owners substituting the company's own preamp for something else).

    So the bass definition was the first thing; the next thing is (again - this only becomes apparent after moving from the Crimson to the Nord) that the Crimson seems to have two "humps" in the frequency response, one in the lower midrange and one in the mid-high trebles. While these humps (not measured, just my subjective impression) make the music exciting, they also make it less natural, and in louder volumes, the higher "hump" sometimes makes the high notes fatiguing.

    While at first hearing the Nord sounded less lively to me, now, after listening to a certain piece on the Crimsons, then on the Nords, there's a moment of "Oh, so that's how it sounded when recorded" or "without the equalizer".

    Why then was I disappointed? Well, I think that what happened is similar to what happened when I bought a Dynavector phono stage. Ever since my local dealer passed away (sad story, he was young) I have been buying hifi blind, without auditioning. Crazy, I know, but circumstances are such that I cannot do otherwise. When I bought the Dynavector, I was expecting to be floored by its performance. Instead, it was better, but not earth shatteringly so. Similarly, the Nords are (I think, still not 100% sure) better than the Crimsons, but it's not like they wipe the floor with them.

    The simple fact is that the Crimsons, when sold in the early 2000s, were a huge bargain. Today the company jacked the prices way, way up, and I think now they may have more competition. The preamp that I have cost 450 quid when new. The new one costs 5400! The monoblocks sold for less than a 1000 quid at the time, while the current model costs about 4500. I am almost certain that the power amps are not hugely different than the old generation. The new preamp is something else, all SMD and with no moving parts and apparently very good.

    ANYWAY, I have a NVA passive preamp coming soon and I hope this will throw the differences into even sharper relief.

    When the preamp was away, I also listened a bit through a late 1990s Rega Elex I have recently purchased to give as a gift to my sister. I must say I was underwhelmed, but then I was comparing it to gear several rungs on the ladder higher, not just one.

    If you've read this far you might as well reply, if you have anything to say... I will post again once I have finalized my impressions and have a verdict. The question now is this: There is a difference, yes. Is it worth 2000 pounds?
    Good luck with the NVA .. let us know how you get on
    A good earwash may be the cheapest and best upgrade to your system.

  16. #16
    Join Date
    Sep 2016
    Location
    Rickmansworth
    Posts
    83
    Rep Power
    14066

    Default

    As above, don't think you'll be disappointed with the NVA and thanks for posting the review.

  17. #17
    Join Date
    Feb 2008
    Location
    Carmarthenshire, West Wales.
    Posts
    1,008
    Rep Power
    155401

    Default

    Hmm.. I think you will prefer either Avondale NCC 200 based mono blocks or NVA A40/60/70/80 monoblocks and perhaps NVA Cube speakers?

    Read this…

    http://www.audio-talk.co.uk/phpBB3/v...php?f=4&t=6892

    and this…

    http://www.audio-talk.co.uk/phpBB3/v...php?f=4&t=6923


    Regards

    John R.

  18. #18
    Join Date
    Sep 2016
    Location
    Rickmansworth
    Posts
    83
    Rep Power
    14066

    Default

    I'm sure if the OP likes the NVA pre he could just be tempted to try your recommendations John.

  19. #19
    Join Date
    Nov 2008
    Location
    Jerusalem, Israel
    Posts
    89
    Rep Power
    14140

    Default

    Since I wrote my very long first impressions I have done some more listening. It is weird: in some cases, the Nords seem to have a flatter frequency response, better soundstage and tighter grip on bass than the Crimsons. So: a slight edge over them.

    And then there was this one song late yesterday night where they outdid the Crimsons in every single aspect and by a wide margin. Immediately upon hearing the vocals with the Crimson I could hear a very subtle but - certainly existent - distortion accompanying the voice which I did not hear with the Nords.

    Regarding JohnR's comments: I have only bought floorstanding speakers by Royd after living with a pair of Royd bookshelves for very long time, so I am unlikely to try NVA cube speakers. Speakers is also one thing I needed to overcome a mental hurdle to buy without first listening and I did so on the strength of knowing the company's sound and having had not one but two of their models in the past.

    Regarding amplification - I don't think I'm gonna return 2K quid amps to the UK, and privately import NVA monoblocks.

    I may take the opportunity to try another type of op-amps in the Nords, though.

    On an aside, my personal communication with the head of NVA was less than delightful. I will not say anymore than this.

    I have bought direct from many people including people on this forum - J7 and JohnR - and others. Indeed, I bought the Nord amps direct from Colin North.

    When you sell direct you have to deal directly with customers. They can have few or many questions and a language barrier may or may not exist. Their questions may come before, during or after the sale.

    I have nothing but praise for the above two gents and this regards both their products and my communicating with them.

    Suffice it to say for now that I will judge the NVA product - once it arrives - purely on its quality, because while my communication with NVA has not been dreadful, it has also been at times quite frustrating. I really would not like to say more.

    By the way I bought the P50sa which is also the second or third best preamp they make. I think I'd be driven nuts with two volume pots as the P90 models have.

    I am trying to understand how some passive preamps on the market reach the prices they reach, and the only word that comes to mind is "bullshit". I can't see what kind of technology makes some passive pre's cost 2000 or more.

    In the picture you can see the Crimson 610 running the Nords, while the monoblocks are turned off. I will be building a wider rack that can accommodate the Nord amps side by side.

    The cardboard covering the record is there because: cats.
    Attached Images

  20. #20
    Join Date
    Sep 2016
    Location
    Rickmansworth
    Posts
    83
    Rep Power
    14066

    Default

    Sorry to hear your dealings with NVA have not run smoothly, and hope you have better luck with his pre. Regarding my last post I had not realised your location.

+ Reply to Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts