ECP Audio T4 Headphone Amplifier

Discussion in 'Headphone Amplifiers and Combo (DAC/Amp) Units' started by TomB, Aug 6, 2018.

  1. TomB

    TomB MOT: Beezar

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    Just a quick note in case I left a misunderstanding about changing tubes in the T4 -

    Yes, unless you use a tall tube like the 6289 or 6414, you will need to remove the lid to change tubes. That means 8 Philips head screws need to be un-screwed. They are very, very short, so it's not like you are twisting your wrist for several minutes.

    However, the spudger tool is needed to simply lift the lid. Doug tries for almost seamless casework in his designs. (He often succeeds!) So the lid can sometimes be wedged a bit. By no means, however, is it like the casework on an iPod/iPhone/Android. The spudger is not needed to push into a seam. It's simply that once the screws are unscrewed, there's nothing to grab onto to lift the lid. It can be slightly wedged sometimes, but if the tubes weren't there, use of a finger in the tube holes is all that's needed to pop the lid up enough to grab it on the edges and lift it away.

    Unfortunately, there's very little chance the tubes aren't going to be there. The spudger is thin enough to slide in-between the side of the tube and edge of the tube hole. You position the end of the spudger under the case lid at that point and lift. Then your fingers can grab the edges of the lid and move it out of the way. (The spudger is not balanced enough to lift the lid entirely without dropping it.)

    I used a dental pick to pop the lid for a long time on the prototype, but that was because I wasn't so concerned about scratches around the tube holes. The spudger won't scratch. If I could've found a plastic hook that wouldn't easily bend, I would be using that and including one with the amp. The spudger won't bend and is the best thing I've found. It's also a useful tool for other things not T4-related.
     
  2. ogodei

    ogodei MOT: Austin AudioWorks

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    Sniped. Also hoping to get in line for the DSHA 3F.

    Doug may singlehandedly be the benefactor to my audio budget for the next 10 years.

    @TomB Any concern about using quality socket savers to raise the tubes?
     
    Last edited: Mar 11, 2019
  3. TomB

    TomB MOT: Beezar

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    Every time I've tested an amp with socket savers it's noisier.

    I described the process of removing the lid in excruciating detail. It's really just 8 screws, a few turns each, get something to pop the lid up that doesn't scratch and move it out of the way. Also, make certain it's off and unplugged.
     
  4. purr1n

    purr1n Desire for betterer is endless.

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    If anyone does something like this with their T4, @jexby, @JK47, and I are coming over to your house and giving you a proper beating.

    IMG_0767.JPG
     
  5. jexby

    jexby Posole Prince

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    not having heard a T4 yet, yet actually thrilled that it takes (some) manual intervention to unscrew parts and lift lids to change tubes. should help minimize the tube nervosa and hopefully smrt people stick in a good NOS pair and leave em run.
     
  6. Armaegis

    Armaegis Friend

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    Let's be honest here. If they actually enjoy shoving that many dinglehoppers into their crackjacks, you can probably charge extra for the beating as an augmented visceral reality upgrade.
     
  7. Elnrik

    Elnrik Super Friendly

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    Is there an up-charge if I want beat with a padauk, ziricote, or curly maple stick?
     
  8. Armaegis

    Armaegis Friend

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    All upgrade items will be served a la carte.
    Mandatory gratuity for parties of 4 or more.
     
  9. Taverius

    Taverius Smells like sausages

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    This forum needs an "innocently whistling" emote reeal bad.
     
  10. Bobcat

    Bobcat Friend

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    [​IMG]
     
  11. TomB

    TomB MOT: Beezar

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    The T4 loaner and Walnut DAC X have been boxed up, shipping labels prepared, and will be dropped off at FedEx in the morning. They are headed for Theloniusnoop's Arizona meet on the 23rd. :)

    I had a metal hiccup this weekend of about 30 thousandths. It was enough to upset the entire assembly of the T4. I got the metal back from the shop this morning with 30 thousandths shaved off of all the pieces. So, cross your fingers that I can finally get everything assembled this weekend. Sorry for the continued delay. Future T4s should be built much faster.
     
  12. TheloniuSnoop

    TheloniuSnoop Friend

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    Looks like a moose. Or a reindeer?

    BTW, a huge thank you to Tom for sending the units to us for our AZ meet. Can't wait to hear them.
     
  13. TomB

    TomB MOT: Beezar

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    Almost done -

    [​IMG]

    (It's late in the day and a lot of sun coming through the window.)

    Yes, there are only 5 sitting there, but the sixth is already finished and has been burning in with tubes and another Walnut X DAC:
    [​IMG]
     
  14. ogodei

    ogodei MOT: Austin AudioWorks

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    Already acquired several sets of tubes to try and cleared space on the rack, can't wait.
     
  15. TomB

    TomB MOT: Beezar

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    All complete and tested!

    [​IMG]

    I'll be working in the next few days to fashion a link on beezar.com for final payment by the six customers thus far. Then I'll contact each one separately with the info. After that, shipping will commence.

    In another week or two, I'll begin work on another four T4s, plus a couple more DACs. :D
     
  16. atomicbob

    atomicbob dScope Yoda

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    ^^
    "Isn't that lovely?"
     
  17. Taverius

    Taverius Smells like sausages

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    One of those is mine and yet I'm lusting after that workbench setup more than the amp >____>
     
  18. ogodei

    ogodei MOT: Austin AudioWorks

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    Amp arrived, setting it up today.

    @purr1n , where can I get that cool tube bridge?
     
  19. Taverius

    Taverius Smells like sausages

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    I knew it was small but somehow it still hit me upon unboxing just how compact it is.

    Little scare with no sound from one channel, but it was a new cable which is faulty.

    I might need to buy a set of smaller supports for the stand, there's miles of space above it and I wouldn't mind it not standing so proud.

    Would ±8cm be enough air on top of it?
     
  20. TomB

    TomB MOT: Beezar

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    I think I recommended 12 inches in the Owner's Manual. That's over 30cm. Ultimately, it's a judgment call, but 8cm sounds awfully cramped.

    The amplifier circuit is well-connected thermally through the case. However, a very large component of the heat is from the tubes. They radiate quite a bit and it's all vertical, pretty much.

    On a different note, it's unbelievable that FedEx delivered it to Italy before some guys have received here in the states. (Hopefully, two of them will receive it today.)
     

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