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V-fet amplifiers - yamaha b-2 v sony ta-n7b

Discussion in 'Equipment Reviews & Opinions' started by The Fez, Dec 7, 2014.

  1. The Fez

    The Fez Well-Known Member

    Messages:
    566
    Location:
    Melbourne - Australia
    === V-FET SHOOT OUT - SONY V YAMAHA ===

    [​IMG]

    Sony TA-N7B

    - 1977
    - 160,000 yen
    - 100w + 100w 8ohms
    - 21kg
    - Two independent monaural amplifiers
    - Harmonic distortion .01%

    First stage – Voltage amplifier. Dual FET input, a differential cascode amplifier, current mirror output circuit at the first stage and a bipolar transistor cascode amplifier at the next stage.

    Drive stage – Fully complimentary push-pull power amp. – Sony V-FETs 2SJ18 & 2SK60 plus bipolar transistors in cascode configuration. Triple dual output configuration per channel.

    [​IMG]

    Yamaha B-2
    - 1977
    - 200,000 yen
    - 100w + 100w 8ohms
    - 26kg
    - Two independent power transformers
    - Harmonic distortion <.08%

    First stage – voltage amplifier – Dual FET input, a differential amplifier with cascode bootstrap circuit.

    Drive stage – Fully complimentary push-pull power amp. Mirror image, complimentary pairs Yamaha V-FETs 2SK76 & 2SJ26. Two pairs per channel.

    [​IMG]

    ________________________________________

    Power --- I like power! The power of the V-FET! - Both these amplifiers could be considered statement products from their respective manufacturers at the time of release. “High-End” (I hate that term!) late 70’s style. Incredible build quality is evident in both amplifiers.

    I’m no professional “reviewer” of hifi gear; these are simply my subjective ramblings about how these amps sound in my own set-ups.

    Preamplifiers

    1. Musical Fidelity A3CR Dual Mono preamplifier
    2. “Parley” A single valve (12AU7) preamp with Jfet/buffer driver stage designed and built by retro-thermionic. http://retro-thermionic.blogspot.com.au/

    Sources

    1. Squeezebox Touch (EDO)
    2. Audio-gd NFB 1.32 ESS Sabre DAC
    3. Yamaha CD-S1000 Player


    Speakers

    Krix Apex Floorstander

    ________________________________________

    Yamaha B-2

    The B-2 is a super amplifier. No, wait a super-duper amplifier….

    Plenty of power on tap, more than enough and the Yamaha delivers the sound very nicely. The B-2 drives the 4ohm Krix speakers with ease, up to very loud levels if you so desire, always very composed.

    I describe the B-2’s sound as clean and dry. It’s extremely accurate, and less smooth or musical than the Sony. The bass is deep and very well defined and controlled. Midrange is very close to neutral in my system, maybe just a little backward compared to the N7-B. Highs are nicely detailed.

    Soundstage of the B-2 is excellent; it bests the N7-B in this regard. It’s big, detailed, and wide just great. It comes close (from memory) to the best soundstage I’ve heard, in a power amplifier, the Sony ESPRIT TA-N902.

    The B-2 in my system performs better being driven by the single tube pre-amplifier. It does sound good with the Musical Fidelity, but my recommendation to all B-2 owners is – you should try it with a tube preamplifier. I think being an all v-fet output stage; the B-2 is a little fussier when it comes to preamps

    [​IMG]

    Sony TA-N7B

    The Sony TA-N7B – revered by some as the best power amplifier ever made - period. It’s the biggest call isn’t it! It’s a very refined sound. Transient speed and dynamics are wonderful. It’s a “quick” amplifier the N7-B. Low frequency is amazing. The amplifier goes so low and with wonderful definition and control, deeper than the Yamaha.

    Stereo imaging and soundstage is very good, however it’ is not as deep and wide as I expected - not as good as the Yamaha.

    The N7-B has a sense of transparency about it that is just wonderful. It is a beautiful sweet and open sound. Don’t misunderstand, the Sony is not a “lightweight” sound, it also has plenty of “grunt” but it also has this beautiful openness to its delivery. A unique combination in my experience.

    More forgiving than the B-2 regarding preamp matching, the N7-B is just as good with either preamplifier.

    Sony did something unique with the TA-N7B. As a good friend of mine said, the N7-B is a “solid state power amplifier R&D project”!. The ultimate sonic signature being the goal at the time, never to bettered.

    [​IMG]

    Conclusion

    In many ways it’s ludicrous to compare the Sony and Yamaha. How do you “choose” between these two amps? Simply you don’t. If you are lucky enough to have both, you enjoy each one as they are. Both amplifiers are designed and built to push the limits of sound reproduction and technology. And both sound very, very good.

    It does not matter what type of music you throw at these two amps, they will never be flustered or stressed.

    Both amplifiers are brilliant – simple as that.

    Footnote

    I’ve mentioned before that the Krix speakers are not the best that could be put in front of these amplifiers. They are passable for sound, however you can obviously hear the potential of both amplifiers, and the Krix are at a point that cannot reproduce the full potential of each amplifier. And others that I have.

    I have been researching and looking at options for a major upgrade in speakers for many months now, but have yet to purchase another pair.

    Music

    Amy Winehouse – Lioness Hidden Treasures

    John Lee Hooker – Mr Lucky

    Melody Gardot – My One & Only Thrill

    Angus & Julia Stone – Down The Way

    Kraftwerk – The Man-Machine

    Michael Jackson – Thriller

    Led Zeppelin – Led Zeppelin IV

    The Alan Parsons Project - Pyramid

    :D
     
    Last edited: Dec 9, 2014

     

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  2. mad shadows

    mad shadows Super Member

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    Nice review. :)
     
  3. Mark B

    Mark B Yamaha Fan Subscriber

    Messages:
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    Location:
    usa
    Thanks for the write-up and pics!
     
  4. MX117.MC7150

    MX117.MC7150 Listener Subscriber

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    Nice write-up. Thanks.
    Surprisingly similar to the comparison that Yamaha B-2 wrote ~10yr ago when he had both. The only difference my shaky memory of that review might be in how deep the B-2 goes compared to the TA-N7B. IIRC, Y B-2 thought that the B-2 was better in the bass region, but that could also have been a result of his changing some coupling caps to 2uf rather 0.47 (again, my memory, as always, might be a bit suspect on the details). Also, you state the Sony is "less" forgiving of preamps. Perhaps you meant more forgiving as it did not seem to care. I do recall that Y B-2 also thought the B-2 was at its best with a BAT preamp that was all 6922 tubes. Great pair of amps.
     
    Last edited: Dec 14, 2014
  5. cjfrbw

    cjfrbw New Member

    Messages:
    2
    VFET with directly heated triode preamp

    I often listen to my Yamaha B2 with a mercury vapor rectified 26 directly heated triode preamp on full range quasi ribbon panel, or with a Manley Neo 300b preamp. I also use it as a Stax headphone amp.

    I agree with Srajan Ebaen that the combo of DHT tube preamp and a VFET/SIT amp is the best sonic combo. It is certainly the most hypnotically magical. I have trouble tearing myself away. The sound is almost indescribable in its midrange and upper midrange beauty.

    Where any other transistor amp tends to inevitably go slightly hard or bitter in the tone, the VFET just goes deeper and sweeter. Piano, vibes and horns are unrivaled.

    I heard Nelson Pass Sony VFET monster at the California Audio Show with the Sony speakers. It sounded wonderful, but I would have loved to have paired it with a DHT preamp.
     
    Last edited: Dec 8, 2014
  6. mwhouston

    mwhouston New Member

    Messages:
    7
    Location:
    Southern Vic. Australia
    The Fez: followed a link from my retro-thermionic blog stats to your review. Got a shock when I saw Parley there then twigged it was you. I have to admit they look like two big powerful serious amps. Nice little collection to have. Looks like you have a nice clean setup there.
     

     

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  7. Saint Johnny

    Saint Johnny Bon Ton Roule Subscriber

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  8. SoCal Sam

    SoCal Sam Lunatic Member

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    Great write-up. You really give an idea of what it would be like to own these beauties.

    At one time I had a B-2 and TA-5650 and compared them to each other and to a pair of MC60's. Of all the ss amps that I have owned and heard, VFET amps sound closest to tube rectified tube amps. The speakers for this comparo were the incomparable NS-1000M. The NS-1000M was pictured with the B-2 in Yamaha literature.
     
  9. The Fez

    The Fez Well-Known Member

    Messages:
    566
    Location:
    Melbourne - Australia
    It's a lot of fun to compare and listen to both amplifiers. Great to have these two classics in use and pumping!!

    I noticed I didn't have a shot of the M.F. Pre...Here it is..

    [​IMG]
     
  10. Mark B

    Mark B Yamaha Fan Subscriber

    Messages:
    5,603
    Location:
    usa
    A friend of mine has an A3CR preamp. It has a heck of a power supply and is a very nice sounding piece. :thmbsp:
     
    Last edited: Sep 23, 2018
  11. MX117.MC7150

    MX117.MC7150 Listener Subscriber

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    If memory serves, Yamaha B-2 used a pair of the Yamaha NS-1000 (rather than the NS-1000M) in his comparison. Nice pair of 1000M's (formerly owned by Yamaha B-2) in Barter Town.
     

     

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  12. The Fez

    The Fez Well-Known Member

    Messages:
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    Location:
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    In terms of new speakers. I think I may have narrowed it down to Orpheus. Australian made speakers, right here in Sydney....:yes:

    http://www.orpheusaudio.com.au/
     
  13. Vint Age

    Vint Age B-1 With Yamaha

    Messages:
    2,221
    :tresbon: :thmbsp:
     
  14. Saint Johnny

    Saint Johnny Bon Ton Roule Subscriber

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    Just wonderin'. Whatever happened to Yamaha B-2?
    I know he really liked all his VFETs, both Yamaha and Sony. And he was also fellow Jerseyite. I have not seen him post in quite a few years. :scratch2:
     
  15. MX117.MC7150

    MX117.MC7150 Listener Subscriber

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    He got kicked off of AK, which was not all that uncommon back then. AK has "mellowed" since those days.
     
  16. Stoffie

    Stoffie Sony afficionado

    Messages:
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    Location:
    Flanders, Belgium
    Interesting review. You are lucky to own both these amps! I have been pondering to try my TA-N7B with a tube pre. Sound with the TA-E88B is very clean and potent but I am curious.

    Good to read Y-B2's spirit is still living on!
     

     

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  17. The Fez

    The Fez Well-Known Member

    Messages:
    566
    Location:
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    highly recommended
     
  18. Spixycat

    Spixycat New Member

    Messages:
    18
    You could plug in i.e. a Sony CDPX707ES/CDPX777ES directly into an power amp skipping the preamp all together... These beautiful CD players do have a volume output control.

    :)
     
  19. Brian

    Brian An Old Geezer

    Messages:
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    Location:
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    He got kicked off? I do not remember his as caustic, rude or otherwise. He was firm in his opinions but, I think most of us are.
     
  20. The Fez

    The Fez Well-Known Member

    Messages:
    566
    Location:
    Melbourne - Australia
    I got a ESPRIT TA-N902 to do that with my Yamaha CD-S1000 player. Use the N-902 variable input. Superb. [emoji3]
     

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