Massdrop x Eddie Current ZDT Jr. (Official Thread)

Discussion in 'Headphone Amplifiers and Combo (DAC/Amp) Units' started by Hands, Nov 15, 2017.

  1. Dzerh

    Dzerh Friend

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    So it is practically the solution SBAF came to. I thought it may be something more interesting. Thank you.
     
  2. Zampotech

    Zampotech Friend

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    Yes, the idea is the same. The practical implementation is very simple.

    PS: as I know, the manufacturer has started to put such screens on all amplifiers and soon I will be out of work :confused:

    [​IMG]
     
    Last edited: Jun 18, 2019
  3. EagleWings

    EagleWings Friend

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  4. StageOne

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    So if one was to pick up a new/used ZDT jr and it was found to have the hum, where can you purchase the necessary quantity of transformer steel? I've searched but have not been able to find anything for reasonable cost or quantity.
     
  5. Ringingears

    Ringingears Honorary BFF

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    @atomicbob or @CEE TEE might have some ideas on this.
     
  6. Dzerh

    Dzerh Friend

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    I have two thought about it:
    1. Laconic Lab and Drop know about the problem so getting humming amp, I hope, pretty unlikely now.
    2. I don't think you actually need transformer steel or it is the best choice. You don't need to fight eddy currents in this application. I think it is just convenient to use if you have it.
     
  7. CEE TEE

    CEE TEE MOT: NITSCH

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    I'd have to check and see if we have any extra in the office...
     
  8. StageOne

    StageOne Friend

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    With the new amps, I would not expect the humming to be a problem, but I've found a few at a significant discount and I'm willing to bet they exhibit the issue. Since @Zampotech has shown a good solution, I'd like to pick one up and apply the fix if needed but sourcing the materials has been difficult. I found "transformer steel" by the ton at roughly $800 but that's probably more than I need. If @atomicbob or @CEE TEE have insights on this, I'd appreciate it.
     
  9. yotacowboy

    yotacowboy McRibs Kind of Guy

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    I used this - easy to cut with kitchen shears and although a little expensive compared to some high nickel content steel flashing, it completely eliminated the hum that was barely noticeable in the first place on my ZDT Jr.
     
  10. Ringingears

    Ringingears Honorary BFF

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    Thanks my friend. \/
     
  11. pure5152

    pure5152 Friend

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    I literally just got my new ZDT Jr unit and have only listened for around 30 minutes, so take this with a grain of salt. But just wanted to give you guys a heads up that I'm getting hum in the left channel. Not sure if it's any quieter than before, because I've never had an older unit, but it's pretty noticeable, even when playing music. (Note left channel only, right side is quiet.)

    Because I just received it, I'll hold off on detailed sound impressions until I listen to it more (and new-toy syndrome abates). But I'll say that even despite the left-channel hum, it's still definitely worth the $400 I paid in sound-quality; just wish my unit didn't have humming when I thought they would have fixed it for all units by now.


    EDIT: f**k me, I should clarify these are with sensitive IEMs (tunai piano), which in hindsight was stupid for me to jump to conclusions with. With my Sony MDR 7506's (the only other headphone I can find nearby at the moment) with an impedance of 60ohms, I hear no hum at all. I'm going to go to a friend's place to try out more headphones, but this may be an issue with only sensitive IEMs. Take this with a grain of salt.
     
    Last edited: Jul 2, 2019
  12. Hands

    Hands Overzealous Auto Flusher - Measurbator

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    Why would you get an amp like the ZDT Jr and plug IEMs into it? It’s only barely suitable for low impedance dynamics. More or less built for high impedance cans.
     
  13. pure5152

    pure5152 Friend

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    Ah yeah, I'm currently away from my headphones, and IEMSs are the only thing I have to test it out with. I know it's stupid, but was just super eager to hear how it sounds. Yeah, I really shouldn't have posted anything before actually trying the amp out with full-size headphones, that's my mistake.

    FWIW, despite being built for high-impedance cans, it still sounds wonderful on the IEMs I'm using (surprisingly enough) haha.
     
  14. pure5152

    pure5152 Friend

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    Hey Lyer I actually do have some high impedance dynamics! I have a verite back home, but just don't have access to it right now (trust me, I really wish I did... if it sounds this good out of relatively cheap IEMs >_o)

    EDIT: how do you delete posts...
     
  15. scapeinator1

    scapeinator1 Once You Go Black You'll Never Go Back

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    So I borrowed one of these from a classmate (for about 10 hours with stock tubes), in order to see if I like it given that the drop is back.

    EDIT: The "fixed" unit I tried didn't have the hum with the 6XX and only a very very slight one in both channels with the focal clear when the clear is plugged into the low impedance jack (@pure5152). I mean, you can't really know if you have the issue until you plug in your verite at least. I have an andro S and it buzzes with literally everything except the RME-ADI 2 IEM output unless I use an IEmatch.

    My first overall impression having it sitting here being fed by the SE output of the ADI-2 next to my Jot is that they are both what I would describe as being in the same class of overall quality. Immediately though, the treble is the largest difference between the two.

    The first thing I noticed was that the Jot's balanced output tends to push the focal clear into being a bit too sharp (~30% of the time for me). Not to the extent that I'm really bothered by it, but I definitely noticed that this happened like much less on the ZDT Jr (~5% of the time with the clear). Which is frankly a welcome reprieve I didn't know I needed. As far as my 6XX is concerned, the Jot pairs really well with it -- it wakes up the treble clarity and the bass is well supported. The ZDT doesn't add a ton here in terms of overall performance. The bass is noticeably inferior and one note in comparison to the Jot with a loss of bass resolution. The bass is still enjoyable though, it's just technically not as impressive as the Jot. I will say that soul music, which is essentially only mids shines on the ZDT Jr. That's the one thing I do really like about it. I definitely got goosebumps listening to "Ain't No Way - Aretha Franklin".

    I know that some people contend that the treble on the ZDT Jr. is a strong suit. And I think its about the same as the Jot. The layering is definitely there on the ZDT Jr, so it edges out the Jot slightly but I personally prefer the Jot with the 6XX in this matchup. I will say though that this is definitely a matter of personal taste. The treble on the ZDT synergizes better with the Clear for the reasons stated above at the cost of some bass performance that you get with the Jot.

    I might try to convince my friend to trade it to me for my old 165 hz monitor, but I'm not really moved into spending 400 bucks for it given that I already own a Jot. It's a good option though.
     
  16. Lyander

    Lyander Official SBAF Equitable Empathizer

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    Yeah, posts got crossed in the mail and I deleted mine after I saw you mentioned just not having access to them, haha.

    Eh, would have been funnier if you expressly got the ZDT Jr for IEMs, but I guess no one's quite that silly. I hope.
     
  17. ML777

    ML777 New

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    My ZDT Jr. came in earlier today. I ordered mine on Sunday (6/30) so this is the latest batch that Drop is selling. So far I haven't had much time to listen to the amp as I had other things going on but I did try with a few IEMs (Shure SE846 and UERR) and Focal Utopia. I'm not going to say much about the amp other than its sounding good and I'm glad I bought it but, again, I haven't had much time with it.

    The main point was to mention I'm not hearing hum but if things change when I listen to it more critically tomorrow I'll update the post.

    I took it apart to check if they are indeed using some sort of transformer steel and sure enough they are. Hope this is a good sign and gives others more confidence to pull the trigger.

    [​IMG]

    [​IMG]

    EDIT: So, I'm hearing a tiny bit of hum in the left channel with the volume down to zero with no source playing. With the volume set to max, the hum is noticeable in both channels but its whisper level. With music playing, even at very low volume, I can't make out any humming. To me, the humming issue is not an issue at all (unless you like to literally listen to your equipment vs music).
     
    Last edited: Jul 3, 2019
  18. Baten

    Baten Friend

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    Awesome, thanks a lot for sharing!
     
  19. Ringingears

    Ringingears Honorary BFF

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    That’s the ticket!!
     
  20. randytsuch

    randytsuch Friend

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    For new owners, in case you haven't read back in this thread, recommended tube upgrade for the front tubes are GE 5654W.
    Bad news is they are a lot more on the auction site than they used to be during the first drop.
    I'm using the Tesa ECC89 for the drivers, I don't even see them right now at the auction site.

    Randy
     

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