ECP Torpedo III [indexed in first post]

Discussion in 'Headphone Amplifiers and Combo (DAC/Amp) Units' started by FlySweep, Nov 2, 2015.

  1. jelt2359

    jelt2359 Friend

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    I don't have a Tiii, but I like that my ECP L-2 (of similar ancestory I believe) is basically the only one of my tube amps that does not require rolling. Tube rolling can be annoying. I'd rather focus on the music.

    That being said I do like to tune the sound with tubes as well, but what I generally do is to get a gist of the sound of the tube, then match accordingly to the headphone or type I'm going to be listening to. So with the HD800 I may pick something more warm, with my incoming Paradox Slants maybe I'd roll in a more neutral and fast tube complement. I've never rolled to find the "absolute best".
     
  2. brencho

    brencho Friend

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    That makes a lot of sense! Still finding my groove though :) tube nomenclature is confusing enough to make the learning curve initially steep.
     
  3. MortenB

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    Yes, I agree about the clarity, neutrality etc of the 801ss. If they match the system and preferences I don't think we can find better sounding tubes. They are quite special.
     
  4. RiddleyWalker

    RiddleyWalker Friend

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    Sorry if I missed it, but any comparison of T3 to T1?
     
  5. bazelio

    bazelio Friend

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    For me, it's not an either/or proposition ... either you enjoy the music OR you roll tubes. I do both. And I generally end up finding tubes that optimize future enjoyment. I don't swap often, but usually find a couple I like and stick with them for a while, swapping only when the mood strikes.
     
  6. brencho

    brencho Friend

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    Makes sense @bazelio im too new to tubes to have a pattern or system in place so time will tell. You might also have keener perceptual skills or a better memory than me because I'm finding differences to be subtle (other than things like micro phonics etc that aren't real descriptors of sound). But again I'm still pretty green and i might more readily differntiate the flavor of tubes once i spend more time with the 3 pairs i have now!

    EDIT I forget who was talking about this on here, but one possibility is that AB/ing things like tubes and gear in general might be approached by listening to a song or snippet of a song with thing A and then immediately with thing B. On the other hand, you might instead spend a few days with thing A and a few days with thing B and let the differences emerge as you spend time with them. i think i'll try that approach and see, because the differences between tubes are subtle but they do exist (say between the amperex and the telefunken that i've tried so far). and over time stronger feelings about them or preferences may emerge.
     
    Last edited: May 30, 2016
  7. TomB

    TomB MOT: Beezar

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    Just to be clear - all four will not fit side-by-side, but it's ridiculously close. I like to be symmetrical, so I raised the middle two by about 1/4" above the pcb. In actual fact, though, you can solder 3 of them flush to the pcb and only push the 4th one up by about 3/8."

    Of course, they all fit lengthwise and in the pcb pads with only a single bend down of each lead.
     
  8. bazelio

    bazelio Friend

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    I think I'm going to use this orientation for the choke. I can't think of a reason not to. This allows a slight gap between it and the transformer and a small piece of double sided tape can fix it to the board. Seem reasonable?

    [​IMG]
     
  9. dsavitsk

    dsavitsk Friend

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    Chokes emit em noise and you have it sitting on the one part of the amp that can pick up such noise. If it's quiet, it's fine, but if it's not, that's why.
     
  10. MortenB

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    You heard the man bazelio :)
     
    Last edited: Jun 1, 2016
  11. MortenB

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    As dsavisk mention a choke will emit noise, so does the wires, especially the wire going to the choke, it's basically a noise transmitter. This is an electronic choke, not a regular choke. If it's better or worse regarding noise emission, I can't tell. What I can tell is, that your location of the choke is right on top of the signal traces on the pcb. As dsavisk has mentioned earlier, this is the one location of the circuit, that is not balanced, and thus the one location sensitive to pick up hum and noise. I'm sure that what dsavisk refer to, when he say ''you have it sitting on the one part of the amp that can pick up noise''. So basically the worst possible location - when considering noise. I can't think of any good reasons to place it there, but that's just me :)

    I chose the location to get the shortest possible wires going to the choke (shorter transmitter of noise), and to get the choke away from the input wires. But as always, there are more than one way of doing things, and more ways than our own can lead to good results...

    But you can try it out. If there is no noise = all good. If there is noise = install it in the position where I installed mine.
     
    Last edited: Jun 1, 2016
  12. bazelio

    bazelio Friend

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    Well we have lift off. Luckily, not a hint of noise that I can detect, so no choke relocation for now. It seems the traces on the underside of the board aren't affected. And it sounds even better than I had recalled from the brief time spent with @drfindley 's unit some time back at the south bay mini meet. I should go to bed... but I don't want to. LOL!

    [​IMG]
     
  13. MortenB

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    Great..! These electronic chokes has the same function of a regular choke, but are made totally different. So they might emit less noise, and they do not have a magnetic field around them as a choke or transformer. The wires to/from the choke will emit exactly the same as with a regular choke and should be kept as short as possible.
     
    Last edited: Jun 1, 2016
  14. hifi01170

    hifi01170 Acquaintance

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    @bazelio please make a comparison with the ZOTL2... I'm very much interested on the differences between both.
    Your ZOTL2 review / feedback was spot on for me so looking forward to your T3 feedback!
     
  15. firev1

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    Hey guys first time constructing a CCS for @HitmanFluffy and my values for current draw seem high for both boards so just checking back on the thread to see that they look okay. Might be component tolerances, current draw seems constant though. Pics respectively for 1st 2nd and edit: overall setup.

    Does it look right???
    13348804_10209060027553461_1554705646_n.jpg 13342166_10209060059834268_591257327_n.jpg 13340626_10209060077914720_1249512517_o.jpg
     
    Last edited: Jun 1, 2016
  16. TomB

    TomB MOT: Beezar

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    Those are well within the range of acceptibility.

    After doing about three dozen of these, mine were almost all closer to 2.4ma rather than 2.2. I think I had one that was 2.5 or 2.6 and one that was down around 1.9ma. Doug said those were still OK, but I pulled them out of the usable batch anyway.
     
  17. bazelio

    bazelio Friend

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    You know.. If there was just a tad more space between C1 and C2, the choke would just drop right in because the lead spacing seems to be dead on for the R2 through holes. Hint, hint... either way, if and when there ever is a T4, I'll be building it as well. Too fun and rewarding not to!
     
  18. firev1

    firev1 Friend

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    Thanks TomB! I believe the term you guys are looking for is a gyrator circuit, they use opamps to mimic perfect inductors without the stray fields, of course, they are not inductors in the sense that they can't store energy having no magnetic field.
     
  19. MortenB

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    Yes, the electronic chokes might be a gyrator, but I don't know since TentLabs are very silent about what's inside the mini e-choke. We can of course flip the argument around and ask: What should be inside that small box, if not a gyrator..? Agreed, these does not store energy, also confirmed by the manufacturer.
     
    Last edited: Jun 1, 2016
  20. MortenB

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    I don't think Dsavitsk and Tom are planning to implement a choke in the future. Their strategy seems to be to optimize the circuit for the best possible CMRR with the balanced configuration, the CSS etc to minimize the effect of noise from the power supply. As mentioned earlier, a choke will most likely have much less effect in such a design, than in an unbalanced amp, where choke supplies can make quite a sonic improvement. Maybe Dsavitsk will comment on his ideas for the future of the amp ? :)

    I just like to have both a circuit that has extremely good CMRR and a low noise power supply. I will replace the electronic choke with the resistor again at some stage to check if there is any effect on sound. In theory it should not have an effect because the circuit is so optimized, but listening sometimes tells a different story...
     

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