JDS Atom Measurements And Review

Discussion in 'Headphone Amplifier Measurements' started by purr1n, Dec 17, 2019.

  1. purr1n

    purr1n Finding his inner redneck

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    upload_2019-12-17_17-58-30.png
    Their gain is off by 0.20db with the Heresy having higher output, but close enough. Gain at "x1" setting is -0.92db and -0.72db for Atom and Heresy respectively, essentially unity gain. Performance between the Atom and Heresy is also essentially identical. Note that 20dbU is 7.75Vrms, which will surely melt the voice coils in your headphones.
     
  2. purr1n

    purr1n Finding his inner redneck

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    upload_2019-12-17_18-9-4.png

    This is approximately -3dbU ~ 0.55Vrms at the output give or take given the slight differences in gain. Again, essentially the same. Note that the Heresy as a few AC mains harmonic spikes. They are of no consequence. No one can hear this and John Atkinson's analyzer not too many years ago couldn't even pick up this stuff.

    Also note that I got absolutely zero AC mains (well maybe a tiny hint at 420Hz) with the JDS Atom. This is very different from ASR results where Amir got a "huge" -125db spike at 60Hz. How this is possible given my far "inferior and less expensive" AverLAB compared to the TOTL AP-555? Here is a possible explanation why: https://www.superbestaudiofriends.o...s-tru-schiit-magni-3-heresy.8576/#post-279495
     
    Last edited: Dec 17, 2019
  3. Roget

    Roget Rando

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    Will you compare to Heresy using blind test as with 3+? Objectively, Heresy and Atom should sound the same. The measurements are exact almost.
     
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  4. Grattle

    Grattle Acquaintance

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    I had an Atom for less than a day before returning it. Mine came with a busted power supply. If feels cheap and crappy. They put weights in it because it's so light. Just crappy build quality all around.
     
  5. lagadu

    lagadu Acquaintance

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    Why would they sound the same? All that these measurements show is that the two amps have the same distortion profile when fed a continuous specific signal. As far as I can tell by itself that doesn't tell us whether they'll sound the same.
     
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  6. purr1n

    purr1n Finding his inner redneck

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    THD+N from 20-20kHz. Both Atom and Heresy have almost exactly the same performance. The levels of distortion do not change and stay consistent across the frequency band for these measurements. Note that bandwidth was set to 44kHz to more appropriate cover distortion from 10kHz and up.

    upload_2019-12-22_18-33-42.png

    upload_2019-12-22_18-37-56.png
     
    Last edited: Dec 22, 2019
  7. purr1n

    purr1n Finding his inner redneck

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    Multitone Test

    Atom has a few db lower noise than Heresy, but both amps perform exemplary here.
    upload_2019-12-22_20-3-56.png
     
  8. NationOfLaws

    NationOfLaws Friend

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    I do like seeing JDS performing well enough to hang with bigger companies. They’re right across the river from me and super nice guys. It’s a “local boy does good” kind of vibe.

    I mean, I just sold my JDS Labs DAC for a Schiit Bifrost MB, but they don’t need to know that.
     
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  9. purr1n

    purr1n Finding his inner redneck

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    I'll do the blind test. I am curious myself. These two amps do measure extremely similar to each other. This doesn't happen often.
     
  10. Baten

    Baten Friend

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    Interesting indeed. I'm really looking forward to this comparison ;)
     
  11. purr1n

    purr1n Finding his inner redneck

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    Wut? There are weights inside it?
     
  12. bboris77

    bboris77 Almost "Made"

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    Yes, they put weights in it so it would not move around when you are adjusting the volume.

    Here is a teardown video. The weights are shown around 8 minute mark.

     
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  13. RobS

    RobS The Friend formerly known as treboR

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    LOL that video makes the amp look worse than the pictures. 22 minute video though? I can do a 5 second video of me tossing it in the trash. The weights help to keep it from moving at the bottom of the trashcan.

    purr1n why did you waste money on buying this crap?

    Amir is such a piece of shit for bitching about "solder splatter" on the Magnis when that Atom looks like a free toy from a Lucky Charms cereal box.
     
  14. purr1n

    purr1n Finding his inner redneck

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    The pictures that i saw of the Atom on ASR make it look great. When I said tupperware, I really meant tupperware.

    Interest from @atomicbob and also to see if it sounded any different from Heresy. Without a blind test, it actually sounds very similar to the Heresy. I'm not going to waste my time further. Like Heresy, it sounds dreadful on x1 gain, on high gain, it sounds pretty decent. I figured we should cover Atom too as a check on Amir's honesty (or really half-truths, what he tends to leave out).

    Anyway, I did pop the case. Indeed, there are four weights stuck on the corners of the tupperware box. I'm not sure what to think.
    IMG_20191225_102447.jpg

    Volume knob position or whatever, the build of the Atom (and the Atom volume knob) is significantly inferior to Topping and Schiit gear.
     
    Last edited: Dec 25, 2019
  15. RobS

    RobS The Friend formerly known as treboR

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    LOL ASR is the Tupperware party of the audio world.
     
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  16. Roget

    Roget Rando

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    The case looked like metal in the pictures at Audio Science Review. I thought it was metal. Is the amp sliding a problem?
     
  17. Mithrandir41

    Mithrandir41 Friend

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    Um, obviously you're not going to want it sliding all around your desktop when you're trying to use it
     
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  18. purr1n

    purr1n Finding his inner redneck

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    It's actually a non-issue. There are four rubber feet on the bottom which provide good grip. The weight of the case with the corner weights is sufficient to prevent the JDS Atom from sliding all around while adjusting the volume knob.
     
  19. dematted

    dematted Almost "Made"

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    I'd like to add my thoughts on the atom here, if that's okay. I owned this amp for around three days before trading it for a liquid spark, so it suffices to say that I didn't much like it. I initially, however, found it quite difficult to pin-point exactly why I didn't enjoy it. For all intents and purposes, it presented the music "correctly": there was plenty of microdetail (more, indeed, than on my Magni 3), and everything seemed to be delivered cleanly, with a very "black" background and a good sense of space (indeed, more space than on the Magni 3). But something just didn't feel right. And after listening to it a bit longer, I realized that what was missing was any sense of cohesiveness to the music, if that makes sense. Sounds were presented one-by-one in more or less correct fashion, but it didn't feel like the sounds were fitted together into a coherent presentation of music.

    To use words that have been overworn, music sounded "clinical", "cold", and "lean". While these certainly allowed me to perceive a lot of detail in the music, they did so at the expense of, well, the music itself. What was especially concerning was the timbre of sounds. There was a steeliness and harshness to a lot of intruments that sounded downright unpleasant. In fact, I didn't really fully understand the criticisms of the Focal Elex's timbre until giving this amp a good listen, which I felt brought out some of the worst qualities of the Elex without doing much to really enhance its strengths or redeem itself in any other respects.
     
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  20. purr1n

    purr1n Finding his inner redneck

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    This is how I describe gear like this: otherwise
    perfect but I don't want to listen to it - flat and boring.

    It's the same experience I had with the $$$ Benchmark AHB2 power amp when I compared to a used Crest class AB Pro amp. Tonally, the Crest was similar. The Crest wasn't nearly as clear, "fast", and focused, but the Crest was more engaging and had a much deeper soundstage despite it's inferior distortion specs.

    I choose listening engagement over mere technicalities. I will always choose to trade for engagement at the expense of a bit of veil, a bit blur. It's not mutually exclusive though. Trading is not necessary, but getting the best of both worlds means getting better gear as opposed to sidegrading.

    Most novice audiophiles will choose the clarity and focus (after tonal synergies), and then take years to realize how unengaging their system sounds. Sometimes they never get it. Other times, their speakers or recordings make it so that's there no difference.

    FWIW, the THX 789, another 0.000x THD amp, actually sounds colder and more clinical than the Atom. The Atom and Heresy sound alike possibly because they use the same or similar chips from TI.

    The Elex also sounds pretty harsh from some tube amps like ECAF when running vintage USA or EML 2A3s. So it's not just the Atom.
     
    Last edited: Dec 25, 2019
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