Interesting Horn thread Someplace Else (AA)

Discussion in 'High Efficiency' started by mhardy6647, Nov 5, 2018.

  1. Doc put the amp up for sale about the time they were working on the Stereomour II.
    I too had an itch for an all-DHT system, so I jumped on it.
    For me, it beats out my Bottlehead 2A3 and 300B monoblocks.
    Paul B. may have built these.
    shoshin likes this.
  2. EML, either 20AM, 20B, or 30A. I'm thinking something that is robust and does not need much fettling, so maybe transformer coupled (PP or SE). If I decide SE, monkey style direct-couple would be an option. Too may options and for an amp that will be quite different to what I'm used to: a bit nervous spending $$$ on the great unknown. :o

    Yep, 6C6 or 310A seems to come down to system and personal preference. I could live easily with either.
    TubeHiFiNut likes this.
  3. Regarding horn honkiness: I wonder if the liklihood of honkiness, and it's offensiveness, increase as frequency decreases: is the risk is greater for horns operating at 800Hz that at 1,600Hz? Is it harder to seamlessly cross horn-loaded drivers (or a horn-loaded compression driver with a big direct-radiator) lower in frequency?
  4. mhardy6647

    mhardy6647 Señor Member

    I certainly think that most horns sound (much) better when not used within an octave or so of their cutoff. Not sure if I'd qualify the audible issues that result from noncompliance with that advice as honkiness, though.

    Of course, I am currently violating that "octave above cutoff" dictum, but I like to be contrary. :)
    gable and TubeHiFiNut like this.
  5. TubeHiFiNut

    TubeHiFiNut Administrator Staff Member

    Say it's not so..... ;) ;)
    mhardy6647 likes this.
  6. mhardy6647

    mhardy6647 Señor Member

    no, I shan't.


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  7. Question for @shoshin
    I have a 2A3 monkey circuit amp

    Plate- 460Vdc
    Cathode- 216.5
    243.5 V p-k
    -44 V g-k
    Will 172.5 Vdc on the plate of the EML 20B work?
    How would you recommend biasing the 20B?

  8. Some good thoughts in this thread. What I have found to be of utmost importance with getting horns "right" is the amplifier/speaker synergy. Conventional wisdom is that a tube amp wins the day, and for the most part, that is correct. However, some tube amps are just not a good match for horns. I found that my LM 845 based tube integrated did not match well with my klipschorns. Now this is a very good sounding amp, but it just didn't bring out the best in the big horns. But it sounded great with Forte IIIs.

    So replacing the LM with a Decware Torii II made a world of difference. Same transparency and dynamics of the LM, but with a much smoother presentation that suits the khorns. I don't get ANY honky, shouty or otherwise unlistenable sound out of these speakers now. Anything I can throw at them never trips them up. Match made in heaven? Maybe. But certainly a match for my room and my ears.

    Other things are of course, givens. Room treatment is very important. And of course, attention must be given to source components and material. Horns will bear out any crap you put in front of them. So purveyors of cheap receivers and seedee players get what they get.

    So my final thought is one I'm sure many of you have heard before. But most of the time when someone disparages horn speakers it's because all (or some) of the variables were just plain wrong. But get it right, and good horns can hold their own with any design and need have no apologies made for them.

    TubeHiFiNut likes this.
  9. mhardy6647

    mhardy6647 Señor Member

  10. TubeHiFiNut

    TubeHiFiNut Administrator Staff Member

  11. Most DHTs are pretty flexible, but I reckon that might be pushing it. Drawing roughly 10mA, would put the grid at -2V relative to cathode: not the most linear part of the curves and (not having calced it) the gain might suffer. It could "work", but it would not be ideal... probably no better than what you already have.
  12. I have found this to be true as well. I always _aim_ to stick to the octave above cutoff rule, and generally, the closer I am the better it sounds (empirically).

  13. mhardy6647

    mhardy6647 Señor Member

    Currently running the EMILARs (with JBL 2441 drivers) first order at ca. 600 Hz nominal XO -- apostasy :)
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  14. TubeHiFiNut

    TubeHiFiNut Administrator Staff Member

    Emilars and 2441s. 'Nuff said. :)
  15. mhardy6647

    mhardy6647 Señor Member

    There's interesting chatter going on elsewhere about modern high-end horns -- I am just increasingly bewildered by the complexity of the whole subject. Maybe I'll get me some vintage 4" radio shack cone MRs and some 2" cone tweeters with chrome dustcaps & be done with it ;)
    TubeHiFiNut likes this.
  16. TubeHiFiNut

    TubeHiFiNut Administrator Staff Member

    Riiiiiiiiiiiiiiight. ;)
  17. mhardy6647

    mhardy6647 Señor Member

    Well, I'm brainstormin' here... you know, there are no wrong answers when one's brainstormin'.


    TubeHiFiNut likes this.
  18. Thanks for the reply
    “would not be ideal “ is a accurate description of my system, but I like it.

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