Nuforce HA-200: High performance, Single Ended, Class-A Headphone Amplifier

Discussion in 'Headphone Amps (full-size)' started by kazsud, Nov 20, 2013.
  1. zilch0md
     
    The point is to hear the HD800 with a low-feedback or zero-feedback amp, which you've not yet experienced.  But that's OK. Ignorance is bliss.  [​IMG]  
     
    And the HD800 really can discern significant differences between various DACs and amps. 
     
    But really... if you are enjoying the gear you have and you don't enjoy experimenting, then stop and be content in your ignorance of any other potential improvements..  [​IMG]
     
    And...  I love the idea of sticking with nothing but portable gear - more utility for your buck.
     
     
    Ahhhh...  Our tastes are more similar than I thought.
     
    [​IMG] 
     
  2. ngkou
    i thought that lehman and Nuforce HA-200 are both class A amps and i assumed that both have low /zero feedback. So, you are saying that HA-200 is different to lehmann...
     
  3. ngkou
    i want to experiment until i get the 80-90% of the performance .... i dont want to become a control freak (sorry for the expression) trying to reach the 100% lol :)[​IMG]
     
  4. ngkou
    Mike, knowning my current  gear, how much of the performance do you think i have reached so far ? in percentage please [​IMG]
     
  5. ngkou
    The Lehmann has multiple gain stages and thus, probably uses a lot of negative feedback to deal with the distortion created in high energy areas of the signal, but the feedback itself creates low-energy, complex distortion artifacts down near the noise floor that destroy the micro details the HD800 could have easily resolved - reducing soundstage and imaging.and the sense of air.[​IMG]
    Try a low-feedback, true single-ended amp (HA-200)
     
  6. zilch0md
    Hi ngkou,
     
    It's impossible for me to put a percentage figure to how closely your gear comes to the pinnacle of HD800 performance - in part because I've never heard your chain, but I seriously doubt that my best chain comes close to making the most of the HD800.  It seems to scale endlessly. The HD800 is seldom the limiting factor - not even for bass performance. You just have to give it what it wants.  Read this recent post by @johnjen
     
    A couple of years ago, I was at a meet in the Dallas area where @jazzerdave had brought his Cavalli Liquid Glass > HD800 rig. I've never heard any headphone system that was more to my liking than what I heard that day.  At that same meet, I had spent several minutes listening to a Stax system and a Sennheiser Orpheus HE-90 driven by a Headamp Blue Hawaii.  Jazzerdave's HD800 rig was far better, in my opinion - for a lot less money - even though it's way more money than I would ever spend.  It was astonishingly good.  Jazzerdave was using a Windows 7 laptop with XMOS-based USB-to-SPDIF converter providing Coaxial input to a Peachtree DAC and from there into the Cavalli Liquid Glass amp with who knows what tubes mounted, balanced out to an unmodded HD800. It was stunningly transparent, neutral, and natural sounding - with nothing but blackness around every last nano-volt of micro-detail, with bass that absolutely growled when the signal called for it - texture and control beyond belief. The HD800 was very happy on his rig.
     
    I would say it's wishful thinking for me to claim that I am more than 70% of the way to what Jazzerdave's system can do, but I'm not about to spend something like $5000 on such a rig and get caught up in buying dozens of tubes to find the setup that sounds the best.  And it's possible that someone out there has an HD800 rig I would like better than Jazzerdave's.
     
    You and I are "middle-class" audiophiles, my friend - and that's perfectly OK. I have other hobbies in which to spend my money - hobbies in which I am far more creative and productive and find much more rewarding than passively listening to music in my recliner.  [​IMG] 
     
    To answer your question, an amp can be Class A yet still use lots of negative feedback to tame the distortion caused by multiple gain stages. The problem with such designs is that use of negative feedback actually creates new distortion artifacts down near the noise floor at very low energy levels - not easily detected by low-resolving headphones (or speakers), but easily detected by the HD800. This is why (in part) the very powerful but high-feedback multiple-gain-stage amp of the Oppo HA-1 measures well for distortion and noise, but sounds bad with the HD800, while sounding absolutely wonderful with planars and just about every other headphone - because they're not capable of delivering those micro-details in the first place.
     
    Some people think the HD800 has a problem that needs to be fixed. Other than a 6 kHz spike that has been addressed by Sennheiser's new "HD 800 S", I am in the camp that says the fatiguing, brittle edginess or harshness that so many people hear in the HD800 treble (at frequencies much higher than 6 kHz) is NOT a problem with the HD800 - it's a problem with the signal coming into the HD800 - a problem that cannot be detected by less resolving headphones. The Oppo HA-1 has this problem, as does every other amp that uses a lot of negative feedback to remove the distortion caused by multiple gain stages. Zero-feedback amps, like the Metrum Aurix or the $480 Audio-GD C-2, may have other problems, but they do not suffer the degradation of every audio trait that benefits from well-resolved, undistorted, low-energy signals that reside close-to-the-noise-floor.  When the micro-details get obliterated (which is typically the fault of the headphones, not just the amp or DAC) you suffer losses of soundstage, imaging, ambiance / air, and even a naturalness of timbre - in vocals and acoustic instruments. Everything from violins to drums and cymbals can sound less realistic when these low-energy signals are corrupted by use of negative feedback.
     
    I am not an electrical engineer, but from what I've read, the trick in designing an amp that uses no or very little negative feedback is to add power without creating distortion in the higher energy signals. True, single-ended designs manage to do this - as with the HA-200. And I can attest that the HD800 loves the HA-200 - as several other people have found. It would be a more popular amp if it wasn't so affordable and frankly, boring in appearance. Joe Consumer wants gear that looks good and he automatically assumes that if it costs more, it must be better. As I wrote before, the soundstage and dynamics of the HA-200 is better than that of the much more expensive Metrum Aurix, but just a little bit softer in terms of resolution - which I attribute (at least in part) to the HA-200 being low-feedback instead of zero-feedback.  If you want to hear every last morsel of information a DAC is extracting from a given recording, good or bad, use the HD800 with a zero-feedback amp. (I'm not saying all zero-feedback amps guarantee this performance - I'm just saying that you can't get there with high-feedback designs.)
     
    But I think you should just enjoy what you have for a while. The longer you spend listening at any given level, the more experienced your ears will become at discerning the nuances that distinguish good from really good audio - which is actually a curse, not a blessing. Adaptive hedonism will continue to make boring that which was once exciting. You will eventually get the itch to upgrade, then you'll buy something and just because it sounds different, you will find it a welcome change, but switching back to the previous component after a few weeks might reveal what you've lost with that upgrade. My advice is to move  s-l-o-w-l-y  or even, not at all. At some point, you'll realize you are going in circles - as I have been lately, bumping my head against my self-imposed money ceiling.  Enjoy the music!
     
    [​IMG]
     
    Mike
     
  7. ngkou
    Wow Mike !
     You are definitely an audiophile. I dont consider myself as an audiophile... perhaps a bit of a videophile ... perhaps the reason being that i was never proud of my listening abilities [​IMG]
    Yes, I ve read about Cavalli amp before ..how good it is.
    I contacted a youtube reviewer who has my gear Cayin and JVCs and recommends the ifi micro idsd. He said i should hear a huge improvement . This and Hugo Dac are the best he ever experienced. So, I got my hopes high again [​IMG]
    I think, that i am already happy with my current gear and if it gets even better ... then wow. 
     
    Rightnow, i notice some bad recording with terrible hissing from spotify. However, there are other newer recording that are really good with no detected hissing , like pitch black. 
     
    Last night, i watched Mockingjay Part II in 3D Blu Ray with the HD800 plugged on my AV Cambridge Audio head out. As I said before this Amp was very very close to Lehmann Linear performance wise using the HD800 but it was terrible using the JVCs . But then i read on the manual of the amplifier that is is recommended to use high impedence cans. So, I going back to my watching experience last night, i was again impressed with the HD800. It was pitch black when silent , you could year all the micro walking foot noises, extremely detail and most importantly the surround sound was as if i was listenning through my DTS 5.1 speaker system. Unbelievable !
    However, there was something that disappointed me a lot ! The bass was removed completely but when i checked it out , I realised that the AV amplifier does not provide the low frequencies of the subwoofer through the Headphone out. I dont know if i can do anything about it ... 
    I am an electronic engineer and used to build transformers and class amplifiers back in the university in 1989 at a fraction of the cost that htey sell now as a luxury gear... but dont ask me now.. i ve forgotten all the details as almost 30 years gone by [​IMG]
     
    very nice to read your experience, Perhaps i should try the Nuforce HA-200 at some point as it not that expensive 
     
    regards
     
    nikos
     
  8. zilch0md
    Nikos,
     
    You're going to find yourself trying the HD800 with everything.  [​IMG]   Try checking the sound options of your TV or of the receiver, whatever that is, to see if you can select 2-channel audio instead of 5.1.  That might restore some of the bass frequencies you're not hearing when using headphones.
     
    The HA-200 can wait.  Have fun!
     
    Mike
     
  9. johnnyb
    HA-200 arrived last week.  A very nice amp.  The first thing I noticed was the smooth, quality volume control. Since gain isn't too high, I actually use a fair amount of the range of the volume, but no worries about maxing it out.  I purchased it for my AKG K7XX's and it fit my purpose nicely.  Mid-bass filled out and firmed up nicely compared to the Vali.  Also, I was amazed at the warmth and smooth nature of the sound -- something I typically have sought from tubes.  I have a feeling I'm not going to want tube amps any more after trying out single-ended class A.  Now I have to re-listen to my music collection ... :)
     
    zilch0md likes this.
  10. ngkou
    yes you are right, the 2-channel audio includes the missing bass when the disc has the LPCM option,  but when it has only the DTS or Dolby 5.1 then the AV receiver does not bother to merge the LFE channel into stereo . I ve read an article saying that most of AV Amplifiers below $1000 have anemic to non existent Bass through the Headphone amp.
     
    I ve been busy now, evaluating the ifi micro idsd as a dac. As an an amp is as good as the lehmann linear but much more convinient. I am having hard time to notice the difference between Foobar 2k DSD512 and Spotify mp3 320kps "Mind Bomb"tracks because i compare them on different platforms Spotify vs Foobar2k . But up to now, i hear better wider soundstage on DSD tracks. I am not if it is the DAC superiority or just the different platforms and may use some filters  in.
     
    What s the best platform to play DSD tracks on a PC? 
     
  11. zilch0md
    I don't know. Having spent as much as $50 to download individual DSD albums, I'm no longer interested in DSD. The acquisition cost and storage space cost are just not matched by any discernible difference in audio quality (my gear, my ears).  96/24 PCM is as high as I go.  [​IMG]
     
  12. Villy
    I have a question for current and past owners of HA-200 - has anyone tried upgrading OPA2134 with discrete opamp, also the voltage regulators with discrete regulators? And if yes, sharing what brands were used/tried and brief impressions will be greatly appreciated.
     
  13. Armaegis
    Officially, Nuforce does not support users modifying the device, which includes swapping opamps.
     
    Unofficially, I liked the AD8620.
     
  14. Villy
    I appreciate your reply. And think that goes without saying just about any manufacturer, it didn't cross my mind even for a second to consult with NuForce on the subject. My question had to do with head-fi members experience. And to reiterate, I am interested in experience with swapping discrete opamps, if it will be an integrated one then the design is tuned already very well for OPA2134.
     
  15. Armaegis
    With discrete the matter becomes more an issue with size. Both height and width becoming limiting factors. I know a fellow who wanted to try the new Burson V5's but alas they were just a shade too wide to fit next to each other. I think the AGD and Dexa units are even larger and taller. The Sparkos are short enough, but too wide. Not sure what other options there are.
     

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