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What makes a great amplifier?

Discussion in 'audio' started by Allaboutmusic, May 21, 2021.

  1. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    Hmm.. I see most seem to have been taken in by the "what load is it driving" thing... It's pretty unimportant in fact and when I design power amps I don't even give it any thought beyond safety of output devices etc.
  2. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    I consider the sound of power amps crucial to the performance of a good system and that very, very few are good enough. To me it's as important as the differences between speakers once we are talking speakers that are at least pretty good. I'm amazed no one took him up on it... maybe they did and it wasn't reported!
    tuga likes this.
  3. Ray

    Ray pfm Member

    A great amplifier designer. They’re not that common.
    CJ14 likes this.
  4. CJ14

    CJ14 Retired

    So ideally, the SET using valve would need to only use the centre part of the B/H curve of the transformer?
    Could this be done in your opinion with a DC control winding that could force the transformer to be re-biased into the centre and still use a single tube/valve. ?
    Then if this was "possible" could then design of the transformer with a built in sensor i.e. a Hall Effect Linear device to control the "re-biasing" winding but not follow the audio current and the changing B/H curve ?
    This could be done like a DC servo system with good low pass filtering maybe ?
    This would also mean the transformer would be smaller maybe?
    It would also cost less, shorter winding wire less core maybe?
    The control winding could be on one of the legs on a "E Core" with the "Hall" device in the other , thus helping to balance the magnetic field.

    The other possible solution is to reverse the winding current in the Tube Anode winding faster, much faster than you maximin frequency so no high frequency is put into the tube or transformer, this I have done on smaller scale.
    Using 1:100 transformer made by Sowter I manged to make a detector for low signals in the range of DC-1Hz to listen to the Earths plates. Designed it for a company in Scotland called "Ohm" so I had gain but only noise thermal type from the winding wires.

    What are your thoughts? Russel.
  5. CJ14

    CJ14 Retired

    Ray there a lots, but most are controlled , pushed down, bullied by marketing and sales/money men. And have no idea how good they could be if not restrained from meeting with others and buyers and hearing there thoughts, and then being forced to designs in a box designed by control freaks with no skills but power personalities.
    Most of these poor sods work alone and are not allowed or have no interpersonal skills, to mix and bat ideas of each other, it is fun I had this with the many U.S. "design team's" I learned a lot and had fun, but best I enjoyed my work.
    The one in the back room hidden from the world, like most secret weapons is not given is true value or potential. It is our world Money Money and keep these under paid under estimated slaves down, I have seen and experienced this it is wrong.

    Sorry getting on my high Donkey again.
    Darren L likes this.
  6. tuga

    tuga Legal Alien

    In my layman view, SET amplification should only be used band-passed in an active configuration driving "real" horn speakers of very high sensitivity (~100dB or over). Paired with a standmounts (f.e. Leben & SHL5+s) they'll be clipping like crazy and putting out 3 or 10% THD and similar amounts of IMD.
    By "real" horn speakers I mean 4- (+sub) or 5-way devices which produce constant narrow directivity down to the mid- or even low-bass, not a woofer in a bin box and 2" compression driver in a horn.
    Something like this would work:

    CJ14 likes this.
  7. Colin L

    Colin L LOU Attitude Adjuster

    That confines the use is SET’s to about 0.0000000000001% of the rooms / people on the planet. I’ve heard SET’s and big Avantgarde systems, dynamic, big, but coloured and they impose a false ambience to music which pales quite quickly. Plus of course mega bucks and they require a vast room.
  8. tuga

    tuga Legal Alien

    Maybe the “false ambience” was coming from the horns.
    To be fair the same could be said about omnis, or any speaker topology.
  9. CJ14

    CJ14 Retired

    No NO that would be bad I am far to soft to be a business man and a few have walked all over me. They have to learn to be like Trump with skill not mouth plus other APPS . This people see us and think two a penny, but some will and do bite back.
    It crazy set a company up to use the skills of somebody, so the company is based on his work then decide because you want total control and this can not get better (lack of imagination) the first design that was done is the only design the Donkey can. you need them not, so dump them, crazy.
    I can think of three such disaster in my career, from MIH - Magnum, TOCA-SECA, TQ - what the hell is it name.?

    Time now to bash some weeds as the rain has stopped.
  10. Tony L

    Tony L Administrator

    Yes, very much so. No one, no matter how much they like the topology, is arguing they are mass market. SETs have a context and the folk who like and buy them clearly understand it very well. I guess there is an ‘audiophile market bell curve’ with SETs at one extreme, seriously huge D’Agostino, Krell, MBL class A solid state amps at the other, and the majority of us ending up in some variation of the middle ground somewhere. Everything has its context and it is extraordinarily arrogant and condescending to assume the customer base of such kit doesn’t understand it perfectly well.

    I tend to live in the vintage/classic market these days, but a very similar curve exists there too. It is nothing new as there have always be a remarkably diverse range of valid approaches to home audio. I’ve just as much respect for those lovingly rebuilding huge silver-face Pioneer and Marantz receivers, classic Naim, Krell etc, as folk like myself tinkering around with old valve amps and idler decks that are older than we are. It’s all good!

    PS That’s obviously just the real audiophile market. The vast majority of modern consumer audio will be Chinese-made switch mode LSI crap stamped out on a single undocumented and unserviceable board in an integrated landfill-unfriendly plastic speaker/soundbar with a life-expectancy roughly 47 seconds longer than the warranty period…
    darrenyeats, Darren L and Colin L like this.
  11. Dowser

    Dowser Learning to bodge again..

    I’d also say synergy with the loudspeakers. Case in point would be my SE hybrid GM75 monos - best amp I have every heard…driving ESLs. Same amps fail miserably with, for instance, Sonus Faber Concertinos - with them I far preferred my ML No. 29.
  12. RoA

    RoA pfm Member

    I better source replacements for the Formation Duo's now :)
  13. russel

    russel ./_dazed_and_confused

    no eye deer, I design solid state amplifiers as a hobby, I don’t have the time to learn the ins and outs of valves and transformer design.
    CJ14 likes this.
  14. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    By far the cleverest and most intriguing single ended valve amp I know of (not triode) is the Pye Mozart. It's unique.

    I'm amazed that the ideas it uses have not been taken on by others. My best guess there is that it's uniqueness means it would have to be redesigned from scratch, the full R & D program, as there's nothing similar out there and no knowledge pool extant on it. Specifically, the OPT would be the problem.

    An 8WPC SE valve power amp the size of many pre amps that weighs bugger all and gives 0.2% THD and SS type damping factor.
  15. darrenyeats

    darrenyeats pfm Member

    The maxim (however well-intended) could be misused to suggest there's only one kind of distortion.

    For example as we know Jez has his views on NFB and distortion. We could just reply "straight wire with gain innit" and cause him to be enraged, or at least frustrated with our lack of comprehension again!

    So, I think I get what you're saying.
    Last edited: May 23, 2021
    CJ14 likes this.

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