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Review and Measurements of New JDS Labs Atom Headphone Amp

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I have ordered mine on 17th of December, both the Khadas Tone Board as well as JDS Atom.
Neither had come yet.:D
You will love them if they ever arrive. I ordered mine a week or so ago and they are here... The Khadas Atom
 

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It's the first measurement after the dashboard view.
119 dB in low gain, 123 in high.
That was SNR. As far as I know dynamic range and SNR are still different things.
 

flipflop

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That was SNR. As far as I know dynamic range and SNR are still different things.
From Wikipedia:
The concepts of signal-to-noise ratio and dynamic range are closely related. Dynamic range measures the ratio between the strongest un-distorted signal on a channel and the minimum discernible signal, which for most purposes is the noise level.
That's essentially the same as SINAD (signal-to-noise and distortion ratio) shown in the dashboard. Unless you want to argue semantics about the word 'discernible', of course.
 
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Yes it is. It is bolted to the top of the Atom amp. The top is more than strong enough to handle it too. Sounds exceptional to boot.
Wow, I can't wait to get my Atom and khadas. I was thinking of putting the Khadas in a wooden enclosure that I was going to build with my father. Then might bond it with Atom either via hot glue or by screwing it into the Atom enclosure.

I am also planning to make wooden cups for my Denon D2000 with my father. He has a woodworking workshop by his house. I will get the wallnut material from my cousin in a day or two. Will also do the Markl mod with the Dynamat extreme and some cushion. The only thing left after would be recabling with something better and hopefully shorter.
 
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Wow, I can't wait to get my Atom and khadas. I was thinking of putting the Khadas in a wooden enclosure that I was going to build with my father. Then might bond it with Atom either via hot glue or by screwing it into the Atom enclosure.

I am also planning to make wooden cups for my Denon D2000 with my father. He has a woodworking workshop by his house. I will get the wallnut material from my cousin in a day or two. Will also do the Markl mod with the Dynamat extreme and some cushion. The only thing left after would be recabling with something better and hopefully shorter.
Be sure to post it up. I'd love to see the woodwork.
 

emmett

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Will I have any problems using the lineout 3.5 from my Pioneer XPD-30R DAP to the 3.5 input of the atom to run my HD6XX's? (HD650)
 
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From Wikipedia:

That's essentially the same as SINAD (signal-to-noise and distortion ratio) shown in the dashboard. Unless you want to argue semantics about the word 'discernible', of course.
To be honest I've never seen SINAD term used in everywhere else so it's a bit easy to get confused. If it's basically the same thing... Good to know.



It would be nice if crosstalk would be measured always too. For example my O2 for some reason hurts the stereo imaging and I can't think of any other reason than crosstalk (which does pop up in simple RMAA loopback test; though my O2 might be a dud). Though, on paper the crosstalk on O2 is nothing to write home about so I don't know.... Just want to avoid this in the future.
 

flipflop

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To be honest I've never seen SINAD term used in everywhere else so it's a bit easy to get confused.
SINAD is the inverse of THD+N, so it shows the exact same thing, but in a more relatable manner.
Take Ch 1 of the Atom for example. Go to http://www.sengpielaudio.com/calculator-thd.htm and type in -113.679 in the 'Distortion attenuation' field and hit calculate. 'Distortion factor THD (k)' pops up as 0.000207 % - the same value as in the dashboard view.
If you got THD+N, you got SINAD and vice versa.

It would be nice if crosstalk would be measured always too. For example my O2 for some reason hurts the stereo imaging and I can't think of any other reason than crosstalk (which does pop up in simple RMAA loopback test; though my O2 might be a dud). Though, on paper the crosstalk on O2 is nothing to write home about so I don't know.... Just want to avoid this in the future.
This is the unofficial crosstalk discussion thread. The consensus seems to be that it's a non-issue.
Even if your O2 is out of spec, I think a more likely explanation could be the channel matching. It changes with the volume setting, so turning up your volume might reduce channel mismatch and in turn improve the stereo image.
 
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If only JDS Labs applied their expertise to stereo power amplifiers. One can dream...
Yeah, coupled with the balanced Khadas tone board coming in summer from Khadas, that would be unbeatable.
You run the optical spdif input.to the khadas, hook it up to the balanced JDS Labs BalAtom, and output balanced XLR to the headphones, all for under 300$. That would be haven. One can most certainly dream.
 

amirm

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Oh I just want something measurably transparent to drive my speakers...
I am testing a high-performance amp now. And I have the option of testing the Benchmark Audio's power amps which should be stellar.
 

Veri

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Did any of you compare the sound of JDS Atom with Massdrop THX 789? This comparison http://bbsah.com/thread-6507.htm shows that there is practically no difference in the sound between them. Can anyone confirm it?
I didn't even hear any difference between DX3 output and THX 789, I'm sure the Atom will fare the same.
Distortion-free / clean output should always sound the same, anyway ;)
 
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I sold my 789 because I found my ear is not very sharp to differentiate 789 and my laptop output... :(
Plan to get a atom just because it's much cheaper than 789
 
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