ECP Torpedo III [indexed in first post]

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

  1. MortenB

    MortenB Facebook Friend

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    There is no way. When these snap-in type caps are installed, they are installed. You can't move them.

    What you can do is carefully file into the sides of the MEC100 to make it fit. But this is at your own risk of course, once you expose the parts on the inside you have potentially damaged the MEC100 and/or you have parts with a high DC voltage exposed, you don't want that.

    Edit: I did not even check the pitch, but if it's like R2 as bazelio mention it would be perfect to drop it in with no wires soldered. The shorter the connections at this point of the circuit, the better because of the ripple that can make long connections act like noise transmitters. So maybe you can take one for the team and file into that MEC100 and see if it works..!? ;)

    I have not yet tried to take the MEC100 out again to check it's potential influence on sound. So yes: Please let us know what you hear :) If it does nothing for the sound, at least we know that we have brought the ripple from the power supply down as much as possible.
     
    Last edited: Jun 11, 2016
  2. TomB

    TomB MOT: Beezar

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    Cool!

    It would be great to get more people interested in the Solens. The Mundorfs are nice, but I find myself reaching for somewhat bass-bloatey tubes to compensate. Then of course, the Mundorfs are a b*tch to install.
     
  3. MortenB

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    Agreed Tom, the Mundorfs does not have the best tonality for the T3, but they are more transparent, than caps like the Solen.

    I'm hoping for best of both worlds with my plate-resistor-rolling: Keeping the Mundorfs for best transparency and getting the tonality tweaked in a more full and natural direction. I hope to get the experiments started this weekend.

    Another cap to consider is the Jantzen audio - Superior-Z http://www.jantzen-audio.com/superior-z-cap/ They are transparent and very natural sounding, I think they will be a very good match for the T3, and not crazy expensive. I know these well, and I think that with these we will have the transparency of the Mundorfs, good bass and ''body'' as with the Solen, and a more layered and resolved sound as a bonus.

    We will have to go down to 4.7uF though to have a chance to fit them, maybe they are still too big. @Tom, will 4 caps measuring 30mm in diameter and 57mm long fit?
     
  4. Hands

    Hands Overzealous Auto Flusher - Measurbator

    Staff Member Pyrate MZR
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    IIRC the Solens were a bit grainy sounding. Nothing major by any means, and perfectly acceptable for the price. I swapped them out for some also-cheap Jantzen Crosscaps in my Crack and found that grain to be gone.
     
  5. dsavitsk

    dsavitsk Friend

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    The board is meant for 22mm diameter snap-in caps (Tom's BOM mysteriously links to 30mm parts, which I don't think will fit so I am not sure what is supplied with the kits). If you look at Mouser (or wherever) there are 20mm diameter snap-ins available which should give you an extra couple of mm of space. You might, however, have to move to a smaller capacity capacitor (which is fine). Also, check the length to be sure they are not too tall.
     
  6. MortenB

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    Great idea with smaller diameter caps, actually TentLabs recomnend 100uF as the ideal caps before/after the electronic choke. Maybe it's easier to find 100uF in smaller diameter.
     
    Last edited: Jun 9, 2016
  7. TomB

    TomB MOT: Beezar

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    OK. Now I know how I ended up with a couple of dozen snap-in capacitors that wouldn't fit. :(

    Luckily, Mouser has been very nice to me lately and gave me a refund. I'll correct the BOM when I get a chance.
     
  8. Jun

    Jun Friend

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    I am not sure what capacitance to get for replacement. 100uf or 220uf? or somewhere between? I am looking at 150uf capacitors that works right? They are at 400vdc.
     
  9. bazelio

    bazelio Friend

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    I say just do what MortenB or I did for now... It works well for me, anyhow. I don't see a strong need to replace caps. Anyhow, at least for now, so we can get your feedback! :D
     
  10. MortenB

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    Agreed, I did not bother to replace the caps either - for now. I think I have enough hours on my T3 now for all the parts to be burned in, so it's a goo time to do some serius evaluations of the different mods. One evaluation is to replace the MEC100 with the resistor agan.

    I would say though, that even if I can't tell difference in sound with the MEC100 I will still use it since it's always nice to have low ripple power supply. And as mentioned earlier: If a choke (electronic in this case) does not make a sonic difference it's a testament tha the differential cicuit has a very good CMRR as intended by dsavitsk.
     
    Last edited: Jun 10, 2016
  11. MortenB

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    It's not that critical, but 100uF is recommended for the MEC100, so buy 100uF if you decide to replace caps. The optimum cap / resisor combination or in this case the optimum combination of caps for the MEC100 can limit the amount of ringing, see more on the topic in the link. And if you want the perfecly optimum caps for the MEC100 then calculate the value based on the current running through the MEC100. See the formulas here also: http://www.tentlabs.com/Components/Tubeamp/page36/assets/MEC-MANUAL-UK.pdf

    Here is a top quality cap, that is 20mm in diameter, maybe the MEC100 will fit between them: Nichicon NKX-020 - 100uF 450V
     
    Last edited: Jun 10, 2016
  12. MortenB

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    The Amtrans plate loading resistors are in. They are big, but it works fine...

    [​IMG]
     
    Last edited: Jun 10, 2016
  13. bazelio

    bazelio Friend

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    For color blind people like me, they are great resistors due to no color bands to swear at. ;)

    Will check back throughout the day for your initial impressions.
     
  14. MortenB

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    I'm not color blind, but I'm getting old and I can't always see those damn color bands ;) So I trust my DMM more than my eyes now...
     
  15. MortenB

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    OK, time for an update after the rolling of plate load resistors (and some more resistor rolling)...

    This is actually a bit difficult to write since I find it hard to believe what I hear. I have been doing similar upgrades in multiple tube amps over the years and heard similar improvements, but not to this degree. So I have been shaking my head in disbelieve several times since yesterday. This is the first time I work on a headphone amp and maybe the effect feels bigger because we hear the sound much more ''direct'' than in a stereo system through loudspeakers..!? Don't know...

    I really wish that I had another T3 to compare with without the resistor rolling, but I don't, and I'm too lazy to replace these resistors with the standard resistors to confirm what I hear. So I hope some of you -maybe you Tom?- will get the chance to compare two T3's where one has this upgrade and one does not and report your findings here in the thread. I would like to know if I'm making this up, or you hear something similar :)

    Anyway, this is what I hear from upgrading the plate loading resistors, and late last night I upgraded some more resistors with Shinkoh tantalums from my small stash (more on this below).

    This is now a maxed out T3 that is really stretching it's legs..!

    Before I heard a sound that was slightly lean, the tonality was tilted a bit towards the treble resulting in a sound that was slightly flat and without the body needed for natural sound. Well, not anymore...

    I now hear a sound with a very good tonality, I would say it's perfect, not too lean and not too full. The tonality is very ''real'' and natural. And the sound is bold, punchy, dynamic, transparent and the sound stage is now layered and dimensional. I would say, that the effect is bigger than a tube change and there is no compromise here. No lack of transparency, no softness, nothing rolled of. I hear more of everything - and this is what makes me wonder if I'm making this up... But I have listened to a lot of different music I know well, and this is what I (think that I) hear. Also, I have heard similar changes before in other tube amps, just to a smaller degree, so it does make sense.

    After listening for some hours last night I dug into my stash of Shinkoh tantalum resistors to also replace the grid stoppers. They are in the signal path, but the current running through them is next to nothing, so they should matter less sonically than plate loads.

    R9/10 is now 1.5K ohm Shinkoh tantalum (close enough to 1K)
    R5/6/7/8 is now 820 ohm Shinkoh tantalum (close enough to 1K)
    And
    R23/24/25/26 is 100K Amtrans AMRG, 2W

    The Shinkos I have is 1W types that are quite a bit bigger, than the standard resistors, so I soldered them on the back where they keep the CCS boards company.

    These resistors did not give as big a change as the plate loads, but the sound did become even more of what I describe above. The Shinkoh's are very transparent and bold sounding. There's meat on the bones with these. I feel the combination of the Shinkoh and Amtrans is perfect to compensate for the Mundorfs and to max out the T3.

    Please try some resistor rolling and report your impression...


    [​IMG]
     
    Last edited: Jun 11, 2016
  16. MortenB

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    BTW, regarding these resistors:

    Parts Connexion has quite a few of the Shinko's left if you want to try them. Buy the 1/2W types, they are smaller and might fit on the topside of the PCB. Get the 820 ohm or 1.3k ohm. http://www.partsconnexion.com/resistors_shinkoh_half_watt.html

    They also sell the Amtrans AMRG:
    http://www.partsconnexion.com/resistors_amtrans_amrg_two_watt.html

    Here in Europe the best source is Hifi Collective in the UK, they don't have that many Shinko's left though
    http://www.hificollective.co.uk/
     
  17. MortenB

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    Hmmm... It seems everyone left the thread when I started talking about resistors (impression is still very, very positive on those), so maybe it's better to talk about caps again ;)

    New parafeed caps arrived. This should be very good...

    [​IMG]
     
  18. FlySweep

    FlySweep Friend

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    I'm actually interested in more impressions of the resistors (if anything's changed, of course), Morten.. it's definitely something I'm considering for my TIII (provided my builder can accommodate, of course).

    Those caps looks sweet, btw.
     
  19. bazelio

    bazelio Friend

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    I'm interested in the Rike caps too. I've heard great things about those. They're normally compared to Mundorf Supreme Silver Gold Oils. They're said to be a tad more natural, but also a bit less resolving. Were the Q Cap versions too big?
     
    Last edited: Jun 16, 2016
  20. MortenB

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    @FlySweep...
    My impression on the resistors still stand and after the first few hours I have not noticed significant changes in the sound. I think these are essential in hearing the T3 at it's best and it's a cheap upgrade compared to expensive tubes and caps. I no longer find the T3 lean, so I don't need to use the warmest sounding tubes now. But I still find it hard to believe, that I hear such a big effect from the resistors. This is in the direction I expected, but a bigger change, than expected. So I hope someone will check this out and report, if you hear something similar...

    @bazelio...
    The Rike Audio caps should be very nice. I have not tried them myself, but people I know consider them some of the best caps. Very neutral, spacious, resolved, dynamic and with a very natural tonality. The problem (besides the price) is, that the new version of these are very big, and will not fit in the T3. Q caps also much too big. I was lucky to find 4 of the now discontinued original version. The 4.7uF is 40 x 40 x 26 mm, so the same size as the Mundorfs.
     
    Last edited: Jun 16, 2016

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