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2359glenn | studio

Discussion in 'Headphone Amps (full-size)' started by silent one, Mar 9, 2012.
  1. gibosi
    With all due respect, I would point out that those who have built-in Hexfred rectification cannot even try 5-volt tube rectifiers in a GOTL. And thus, it is impossible for them to know if they might in fact prefer vacuum tube rectification. Whereas, those of us who use 5-volt rectifiers can also use one of Glenn's Hexfred plug-ins, and therefore, we can directly compare Hexfred to tube.

    So it might be more valid to ask those who use tube rectifiers in the GOTL if any of us would complain if that ability was taken away. And I am willing to be the first to go on record: I can not imagine being limited to using only the plug-in Hexfred. No way! :)

    Now don't get me wrong... the Hexfred is a very fine rectifier. And I freely admit that chasing after tube rectifiers can be a very slippery slope. But losing the ability to use tube rectifiers as precision tone controls is a wonderful luxury that I would be very loathe to give up.

    But of course, my ears and my gear.... YMMV.
    attmci likes this.
  2. UntilThen
    Very nice system Leftside.
  3. felix3650
    Really nice pics JV. It reminds me of an old electric filament heater I used to have.
  4. felix3650
    Thanks for the impressions guys. Keep them coming!
    Last edited: Nov 11, 2018
  5. felix3650
    HEXFRED should take on variable out of the equation even though I would've gone for a Cossor 53KU. Reading around seems this is a prefered choice for most.

    In fact I did notice that it was MAZDA spelled backwards, but then I thought coincidence? :)

    Noted! I have a Holo Cyan which has a very competent headphone amp section with balanced output. If I do get a planar again (had the ZMF Ori, LCD2F, HE500 and Sundara) I'll have some tube flavors to play with then :)
  6. whirlwind

    Great stuff!
  7. 2359glenn
    I was looking at the specs of the EL11 and they are about the same as the EL3N.
    So close it seems to be a EL3N with a different base.
    Somebody asked about making a amp with sockets fore a EL11 might have to change the plate resistor
    to make these tubes sound there best. That would work for the EL3N also.
    I really don't know why these tubes sound so good with the parameters of a 6SN7.
    felix3650 likes this.
  8. JazzVinyl
    Crazy Nice Gear, LS...!!

  9. mordy
    Hi hibosi,
    You are right, I forgot that you can eat your cake and have it, too. You could order the amp with the rectifier socket, and then use a plug-in Hexfred.
    So in my case I guess ignorance is bliss lol. It seems to me through my reading that rectifier tubes can be temperamental and that they sometimes blow up, more so than regular tubes.
    For tone controls I use the tone controls in my ss preamp section, or sometimes cables. And with the Hexfred you can load in more tubes since the current draw is less from a Hexfred than a rectifier.
  10. 2359glenn
    Yes and no still loose 1/4 of filament current the Lundahl transformer has 4 filament winding's that I parallel if it has a rectifier tube
    I use one for that tube. Then only 3 winding's are paralleled for the rest of the tubes.
    rnros likes this.
  11. 2359glenn
    Here is a 300B amp I am finishing up it has 8 ohm speaker outputs.
    The small tube in the middle is a Amperite time delay tube to do a slow start. Needed because the amp has HEXFREDS instead of a rectifier tube.

    300B 1.JPG

    300B 2.JPG
  12. SonicTrance
    Do you mind sharing a pic of the insides of the 300b amp? It looks very nice!
  13. UntilThen
    What a beauty. Frontal shot please Glenn.

    What are the 2 metal knobs beside the power tube.
    Last edited: Nov 11, 2018
  14. 2359glenn
    Here is a pic of the last one I built that has rectifier tubes.

  15. 2359glenn
    I will shortly back to working on it now.

    The 2 knobs are bias adjustment to set the 300B current.
    Last edited: Nov 11, 2018

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