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JDS Labs Atom DAC+ Review

Grattle

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AnalogSteph

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That ought to be measurable if it's real, analogous to how @tomchr evaluated an LDR job.

Anyway, some have asked why JDS Labs used the slightly older ES9018K2M chip. My guess would be that you can get better deals of stock on older chips, and this one is not a slouch by any means - specs for dynamic range of 127 dB(A) and THD+N of -120 dB are not anything to sneeze at, in fact dynamic range of the whole thing still remains about 10 dB short (though I have a hunch Amir's setup tends to underread with unbalanced outputs). Not like there's much to complain about for the price either way.

I do wonder whether this one will hard-clip at 0 dBFS like ESS DACs tend to do or a bit of digital headroom (attenuation) has been baked into it... with the SPDIF input you could just hook up a random CD player after all, and sparing 3 dB does not seem such a big deal when having such a high-performance DAC.
 

ALex_hha

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I’d buy one just to support a great company if it had SPDIF. I use a pi streaming device and lack of coax SPDIF is unfortunately a deal breaker for me.
it has optical one
 

Angsty

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Not that simple. Actually this filter is the best filter. There's no benefit using faster filter. Look at THD+N vs Frequency it's much better than the jaggy mess isn't it?
I’m curious as to why a faster filter is not technically better than the slower one. Amir has talked about the preference for faster filters in the past, but this implementation seems more typical.
 

JohnYang1997

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I’m curious as to why a faster filter is not technically better than the slower one. Amir has talked about the preference for faster filters in the past, but this implementation seems more typical.
Limitation of the order of filter. You get sharper filter or deeper filter. You can't have both without increasing order significantly. You might get somewhere in between. But if you only care about 20khz and below and no signs of distortion (thd and imd) is shown, this is the more ideal filter.
 

tomchr

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TAnyway, some have asked why JDS Labs used the slightly older ES9018K2M chip. My guess would be that you can get better deals of stock on older chips [...]
Not really. The trend seems to be to stick to the same price year after year. When something new and better comes out, you charge more and stick to that price year after year. At least that's my observation.

I also seem to recall that National Semiconductor at one point (with Brian Halla as CEO) increased the prices on the older parts roughly 10-fold. At the time, National didn't want to keep making LM317s, so they wanted people to stop buying them. I think they came to their senses soon thereafter - maybe when Greg Lowe took over - as they realized that a good chunk of revenue actually came from legacy circuits.

Tom
 

TRKLGND

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Took delivery of my DAC+ a couple of days ago. I currently have a Helm Bolt, an SMSL Sanskrit 10 MkII and a Schiit Modi.
After just a few hours with the DAC+, it is clear to me that I prefer the AKM sound signature. Both the Schiit and the SMSL sound a bit fuller and warmer than the ESS offerings. The ESS seem to have a bit more sparkle in the top end. The DAC+ (ES9018K2M) does sound considerably better than the Helm Bolt (ES9281A). The DAC+ with the tube amp warms things up a bit but I still prefer the AKM based DAC's.
For amplification I am using the Schiit Magni Heresy and an Nobosound FU32 tube amp.
My cans are an older pair of AKG N700NC. I use them with the 3.5mm cable and the power off (no noise cancelling). No laughing please. They really aren't bad. A pair of HiFi Man Drop HE-4xx planars and a pair of Audio Technica ATH-MSR7's.
Nothing esoteric or expensive. My next purchase will be the ifi Zen CAN amp so I can see if the 4.4mm balanced output makes any difference.
I am having a lot of fun in the budget headphone space.
 

MRC01

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I’m curious as to why a faster filter is not technically better than the slower one. ...
Limitation of the order of filter. You get sharper filter or deeper filter. You can't have both without increasing order significantly. You might get somewhere in between. But if you only care about 20khz and below and no signs of distortion (thd and imd) is shown, this is the more ideal filter.
With 44,100 sample per second, Nyquist is 22,050. If you want flat clean response (passband) to 20,000, then the transition band of the filter is 20,000 to 22,050, which is quite narrow, only 2,050 wide or 0.14 octaves. A sharp/narrow filter like this is hard to implement in real time on the hardware available in a normal DAC chip, without passband side effects. So manufacturers "cheat" and extend the stop band above Nyquist to 24,100 Hz. This doubles the width of the transition band, making the filter easier to implement. But what about eliminating supersonic noise and their aliases, which is the very purpose of the filter? Well it happens that aliases reflect around Nyquist, so any aliases of high frequency noise (above Nyquist) are above 20 kHz, pushing them above the passband.

Put differently, in this situation the passband limit is 20k, transition band is 20k to 24.1k, Nyquist is 22,050 which happens to be smack-dab exact center of the filter transition band. Not by coincidence. Worst case scenario, the filter passes energy at 24,000 Hz which is by definition noise since it is above Nyquist. The alias of this frequency is its arithmetic mirror image across Nyquist, which is 22050 - (24000 - 22050) = 20,100. That's above the passband and inaudible. Conversely, the highest passband frequency (20,000) has an alias of 24,100, which the filter fully attenuates.

This is why we so often see the "sharp" filter in DACs that Amir reviews having a stop band above Nyquist at exactly 24,100 Hz. It's an engineering kludge to bend (break) the rules in a way that makes the filter easier to implement while avoiding passband noise or distortion. DAC chips usually don't do this at higher sampling rates. It's not necessary, since higher sampling rates have a much wider transition band, the DAC can fully attenuate by Nyquist with no engineering sleight-of-hand needed.
 
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Yasofnos

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If anyone is interested, the JDS Labs Atom DAC+ can be directly connected via USB to a Roon Nucleus or ROCK server and you can control the volume via the Roon interface. Quite a bargain at $109.
 

bennetng

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I’m curious as to why a faster filter is not technically better than the slower one. Amir has talked about the preference for faster filters in the past, but this implementation seems more typical.
https://www.audiosciencereview.com/forum/index.php?threads/digital-filter-game.23795/
https://www.audiosciencereview.com/forum/index.php?threads/the-new-king.21444/post-793871

The alias of this frequency is its arithmetic mirror image across Nyquist, which is 22050 - (24000 - 22050) = 20,100.
Integer interpolation ratios, despite how bad the quality is, will never introduce aliasing, only imaging.
https://www.audiosciencereview.com/...s-sampler-a-new-2-0-version.23274/post-793907
https://www.audiosciencereview.com/...about-filters-mqa-vs-hi-res.12343/post-366993
 

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With 44,100 sample per second, Nyquist is 22,050. If you want flat clean response (passband) to 20,000, then the transition band of the filter is 20,000 to 22,050, which is quite narrow, only 2,050 wide or 0.14 octaves. A sharp/narrow filter like this is hard to implement in real time on the hardware available in a normal DAC chip, without passband side effects. So manufacturers "cheat" and extend the stop band above Nyquist to 24,100 Hz. This doubles the width of the transition band, making the filter easier to implement. But what about eliminating supersonic noise and their aliases, which is the very purpose of the filter? Well it happens that aliases reflect around Nyquist, so any aliases of high frequency noise (above Nyquist) are above 20 kHz, pushing them above the passband.

Put differently, in this situation the passband limit is 20k, transition band is 20k to 24.1k, Nyquist is 22,050 which happens to be smack-dab exact center of the filter transition band. Not by coincidence. Worst case scenario, the filter passes energy at 24,000 Hz which is by definition noise since it is above Nyquist. The alias of this frequency is its arithmetic mirror image across Nyquist, which is 22050 - (24000 - 22050) = 20,100. That's above the passband and inaudible. Conversely, the highest passband frequency (20,000) has an alias of 24,100, which the filter fully attenuates.

This is why we so often see the "sharp" filter in DACs that Amir reviews having a stop band above Nyquist at exactly 24,100 Hz. It's an engineering kludge to bend (break) the rules in a way that makes the filter easier to implement while avoiding passband noise or distortion. DAC chips usually don't do this at higher sampling rates. It's not necessary, since higher sampling rates have a much wider transition band, the DAC can fully attenuate by Nyquist with no engineering sleight-of-hand needed.
That was a great, full-throated explanation that really made sense to me -- thank you!
 

Jimster480

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Amazing to see how performant the cheaper stuff has gotten over the last years.
 

Haze

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Has anyone tried the "tube like" firmware on this? Seems like a nice little value add.
 

xann89

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Hi guys, new to the audio world and I just received my DAC+ to complete my JDS Atom stack. One question though, does the DAC+ really run very hot (not warm) even in standby mode...? Coming from Schiit Heresy/Modi 3 stack (sold them last year), I am quite surprised that the schiits were barely warm.
 

jseaber

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Hi guys, new to the audio world and I just received my DAC+ to complete my JDS Atom stack. One question though, does the DAC+ really run very hot (not warm) even in standby mode...? Coming from Schiit Heresy/Modi 3 stack (sold them last year), I am quite surprised that the schiits were barely warm.
@xann89 - Yes, quite normal, as we rely on AC/AC transformers and linear regulation. This method will always run warmer than a USB powered DAC. Please find more detail at jdslabs.com/troubleshooting
 

BerserkCore

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I just received my Atom DAC+ and am comparing it to an OL DAC on JBL 308's.

To me the Atom DAC+ sounds muffled noisy and distorted compared to the OL DAC.

I find the following audio track seems to give a pretty good baseline to compare audio sources.

With this the Atom DAC+ sounds like it is muffled and muted, which immediately starts giving me a headache. The voices sound like they're speaking through something and there may be some sort of feed back or timing issue with the audio.

With this I have the same but worse problem with Schiit. It becomes obvious that Schiit equipment has huge distortion and something out of sync between the left and right channel which makes you feel like their equipment is just cheap Schiit stealing the objective's points as a marketing plan.

Am I missing something? JDS Labs no longer seems to be selling OL DAC's and Objectives either.

Maybe the DAC is inferior?
 
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jseaber

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I just received my Atom DAC+ and am comparing it to an OL DAC on JBL 308's.

To me the Atom DAC+ sounds muffled noisy and distorted compared to the OL DAC.

I find the following audio track seems to give a pretty good baseline to compare audio sources.

With this the Atom DAC+ sounds like it is muffled and muted, which immediately starts giving me a headache. The voices sound like they're speaking through something and there may be some sort of feed back or timing issue with the audio.

With this I have the same but worse problem with Shiite. It becomes obvious that Schiit equipment has huge distortion and something out of sync between the left and right channel which makes you feel like their equipment is just cheap Schiit stealing the objective's points as a marketing plan.

Am I missing something? JDS Labs no longer seems to be selling OL DAC's and Objectives either.

Maybe the DAC is inferior?

That certainly does not seem right. DACs should not result in dramatic changes to sound quality. From what you've described, you're encountering a connection issue (possibly at the amplifier). Please email pictures and perhaps we can help pinpoint the difficulty.
 

phoenixsong

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Yup, although my OL DAC sounded slightly sharper (maybe higher third harmonic distortion?) than my SDAC, for the Atom+ to sound that off is a major flag imo
 

BerserkCore

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That certainly does not seem right. DACs should not result in dramatic changes to sound quality. From what you've described, you're encountering a connection issue (possibly at the amplifier). Please email pictures and perhaps we can help pinpoint the difficulty.

This is strait from the DACs through RCA to 1/8 on the back of the self amplified JBL 308's. I can strait swap between the Atom DAC+ and the OL DAC.

While the Atom DAC+ is not terrible, like an onboard motherboard DAC or even a Schiit DAC, it still has the same noisy qualities and is not as sharp as an OL DAC.

There is something about the Atom DAC+'s DAC that is fuzzy or something is not set correctly for it.

I think you can really tell the difference using this track because the left and right channels resonate with each other and any distortion starts to throw that off.

Or like me, instead of listening to it all day without problem you immediately start getting a headache.
 
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