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A rare Yammie preamp...

Discussion in 'Interesting eBay auctions' started by Nero, Aug 6, 2019.

  1. Nero

    Nero It's unlikely

    This is a rare beast. Serious knobbage factor
     
  2. Beobloke

    Beobloke pfm Member

  3. Nero

    Nero It's unlikely

    A good snag for a 240V version! Does it actually have any V-FETs in it though? I thought they were just the power transistors for the B1/B2 power amps.

    Sound any good? I've never heard one
     
  4. ERICLIMPIT

    ERICLIMPIT pfm Member

    According to the vintage Knob,

    Inside
    All-FET, with small-signal V-Fets in some of its stages, constant-current / constant-load / current-mirror / fully-stabilized ±100V / ±33V EQ section, metal film, styrol and mylar caps, separate amp for headphones and a 4-gang volume control.

    pretty good amp by all accounts, crazy price though...
     
  5. Nero

    Nero It's unlikely

    Yes, I won't be buying it. My days of big Yammie amps are over, but I'd be tempted by some of the big Jap power amps that have huge meters. The ones on the B2 weren't big enough for me :)
     
  6. paulfromcamden

    paulfromcamden Baffled

    How does the 'tone equaliser' work?
     
  7. Rug Doc

    Rug Doc pfm Member

    I REALLY want the silver one the op posted to match my other Yamaha silver kit. I don’t want to pay that much though. :(
     
  8. Rug Doc

    Rug Doc pfm Member

  9. Beobloke

    Beobloke pfm Member

    Neither have I but I've always wanted to try one and it was too good a price to pass up. As I said, though it needs a bit of fettling, so i cant audition it just yet.

    And anyway, if it doesn't work, it has external input sockets for the VU meters, so i can always just stick it in my rack, plug somethign into it and admire the bouncing meters and impressive knobbage...
     
  10. Beobloke

    Beobloke pfm Member

    I'm sure we can arrange something. Comparing it to my CX-10000 will be interesting!
     
    Rug Doc likes this.
  11. Rug Doc

    Rug Doc pfm Member

    Ill bring the B-2 to go with it.
     
  12. ToTo Man

    ToTo Man the band not the dog

    The 'Presence' knob of the Tone EQ adjusts the upper mids and the 'Acoustic' knob controls the lower mids. If you look at the 'Turnover' buttons directly below, you can also adjust the centre frequencies, just as you can for the 'Treble' and 'Bass'.

    Somewhat confusingly, the lowest turnover for the 'Bass' is 125Hz, but the lowest turnover for 'Acoustic' is 70Hz. One would perhaps expect the lowest turnover for 'Acoustic' to be higher than the highest turnover for 'Bass'. Likewise the highest turnover for 'Presence' is 4kHz, which again is higher than the lowest turnover for 'Treble' (2.5kHz). AIUI, the 'Bass' and 'Treble' adjustments are shelf filters, whereas the 'Acoustic' and 'Presence' controls are notch filters, so the turnover frequencies have likely been set at where they are believed to be of most use and to encompass the most likely 'problem frequency' areas that a home listener may want/need to adjust.

    EDIT - Can someone please explain why there is a 'Tone Circuit on/off' flick switch below the meters in addition to the defeat buttons below the Acoustic/Presence/Bass/Treble knobs. Does the flick switch determine if the tone settings are sent to the Tape Rec outputs?
     
    paulfromcamden likes this.
  13. paulfromcamden

    paulfromcamden Baffled

    Thanks for the explanation. I haven't seen notch filters on an amp before. Very interesting.
     
    ToTo Man likes this.
  14. Beobloke

    Beobloke pfm Member

    Nothing so exotic! The button below the Tone Equaliser just switches this circuitry on and off. The Tone Circuit On/Off bypasses everything including the Tone Equaliser, conventional tone controls, high and low filters and loudness control.

    If you fancy a read of the manual, which apparently contains "Everything you need to know for operation of this technologically sophisticated and aurally satisfying precision audio component", :D you can download it for free, after registering, from Hi-Fi Engine here:

    https://www.hifiengine.com/manual_library/yamaha/c-1.shtml
     
    ToTo Man likes this.
  15. Beobloke

    Beobloke pfm Member

    I cleaned the Yammie this evening and opened it up for a poke round inside.

    It is now back together, I’m depressed and am currently on my second glass of red.

    :(
     
  16. ToTo Man

    ToTo Man the band not the dog

    Has it been butchered, Adam?
     
  17. Beobloke

    Beobloke pfm Member

    Yes.

    In addition to the phono loading board, which I was expecting to be missing, the main phono preamp board is gone and two items of uncertain parentage have been fitted instead. There are also two further PCBs bodged in, the functions of which I am currently unsure!

    It seems I am not destined to own a Yamaha VFET item with original internals!
     

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