Review and Measurements of New JDS Labs Atom Headphone Amp

[watchnerd]

Are you seeing what I am seeing? SINAD of 114 dB??? In a $99 device? Are you kidding me? Running the same test on Monoprice Liquid Spark struggled to get to 100 dB. This is a good 15 dB better performance.

I was looking at the Allnic HPA-300 because, well, I want a new toy and it looks sexy.

http://allnicaudio.com/?page_id=928

Aside from the relative insanity of buying a headphone amp this expensive (~$3k) when I don't have any headphones worth over $1k, this stat struck me:

S/ N Ratio: -68db (CCIR, 1KHz)

Am I missing something, or is that complete garbage compared to the Atom?

Is it probably due to tube noise?

 

[AresHarvest]

This is tape cassette territory.

 

[amirm]

S/ N Ratio: -68db (CCIR, 1KHz)

Am I missing something, or is that complete garbage compared to the Atom?

It is. Stated THD+N is 0.03% which translates to SINAD of 70 dB. It may measure even worse than this.

I can't think of a single reason to buy it other than looking at it as decoration.

 

[JohnYang1997]

Objectively speaking (from measurements) what gain does "sound" better? Low Gain seems to have better SINAD but has noticeably less SNR. I'm quite new to all of this, so sorry in advance if that's a stupid question to ask. I can run my headphones (beyerdynamic Amiron Home) in both gain modes comfortably and wondered which gain to pick to get the best sound quality.

After doing some testing switching between both of them it feels like High Gain makes the vocals sound a tad clearer in comparison. But that may as well be some sort of placebo effect.

Thanks in advance and thanks for providing this awesome forum completely for free!

We just discussed that one page ago.
Short answer as low gain as possible as long it's loud enough.

 

[dwkdnvr]

I finally succumbed to the pressure and picked up the "ASR Special" package of the Khadas Tone Board and the Atom. They certainly seem to deliver as advertised. Using the pair both with headphones (HD6xx and Viso HP50) as well as with speakers - the Atom feeding a Neurochrome Mod-86 driving Kef Q150s. Unbelievable what $100 gets you these days in the dac and amp/preamp world.

My only desire is that with Khadas apparently coming out with a balanced version of the Tone Board at some point, a balanced variant of the Atom would be a great pairing since my Mod-86 takes a balanced input (just using rca->XLR cables at the moment, and it still sounds great). I am wondering whether getting 2 and trying to use one on each channel with an XLR->2RCA cable would work - whether the channel balance in a single unit would be good enough to serve as a single-channel balanced preamp.

 

[ngs428]

I finally succumbed to the pressure and picked up the "ASR Special" package of the Khadas Tone Board and the Atom. They certainly seem to deliver as advertised. Using the pair both with headphones (HD6xx and Viso HP50) as well as with speakers - the Atom feeding a Neurochrome Mod-86 driving Kef Q150s. Unbelievable what $100 gets you these days in the dac and amp/preamp world.

My only desire is that with Khadas apparently coming out with a balanced version of the Tone Board at some point, a balanced variant of the Atom would be a great pairing since my Mod-86 takes a balanced input (just using rca->XLR cables at the moment, and it still sounds great). I am wondering whether getting 2 and trying to use one on each channel with an XLR->2RCA cable would work - whether the channel balance in a single unit would be good enough to serve as a single-channel balanced preamp.

I have the ASR special too! can’t beat it for the price.

 

[FrantzM]

Stop this people!! I am perfectly content and satisfied with my iFi iDSD DAC/Amp... but the ASR special at $200 !!

 

[magicscreen]

Do you need to burn in the Atom amplifier? How many hours?

 

[AndrovichIV]

Do you need to burn in the Atom amplifier? How many hours?

There's no such thing as breaking in electronics

 

[solderdude]

Do you need to burn in the Atom amplifier? How many hours?

Only some electrolytic caps may show some 'forming' (a higher leakage current) when used for the very first time it is switched on which takes a few seconds to minutes max.
I would not call such a one time short-moment event 'burn-in'.

With some electronics it takes some time to get to operational temperatures and circuits to set to the intended operating points which could take a while each time it is switched on.
When it has cooled down this must happen again each time... it does not 'last' so this is no burn-in.
Tube amps, class A amps or class A-B power amps may take quite some time to get to operational temperatures.
The Atom ... nope.

Electronic components aren't like wine in that they need a certain time to 'mature' or reach optimum sound quality (which is never shown in measurements either)
Most components do 'age' but as a rule not very gracefully and ultimately resulting in failure or poorer performance.
Never in better performance.
Some tubes may become 'better' after a certain time but they too will become worse in the end and fail.

So no need to worry... your Atom (and cables as well as wall wart) don't need any burn-in at all.

 

[Viper Necklampy]

I'm the first running in this defect after just 4 months of usage? In every gain I use, if i put volume from 12o'clocl until 15, right sound is without volume.. And some scratching from 10 to 12 o'clock.. But I find just now that switching volume holding pressed the right part of the volume pot i can put in every volume i want, but only if i come down in volume, not up, fortunately at least

 

[solderdude]

Have it fixed.
The pots in the Atom are relatively cheap and sometimes crap out or become scratchy.
I would return it under warranty.
Contact the seller (I assume JDS UK ?)

Alternatively when you are handy with a soldering iron put in a new one yourself (which voids the warranty)

 

[Viper Necklampy]

Have it fixed.
The pots in the Atom are relatively cheap and sometimes crap out or become scratchy.
I would return it under warranty.
Contact the seller (I assume JDS UK ?)

Alternatively when you are handy with a soldering iron put in a new one yourself (which voids the warranty)

Do you think it will get worse at the point to work no more? Dunno how much i have to pay for tax etc. for warranty from Italy, maybe it's better to fix for myself if not hard.. Anyway in 2-3 months i will get thx aaa 789 and will sell the Atom, so hope no need to fix that if not a must..
Then this happened.. *Brick fall*
Is that bad? D: I Mean audio quality is still the same probably, but it not nicely fixed in my socket plug..

 

[solderdude]

You can try to carefully bend back the mains pin.
I have seen pins snap off when doing this and others bend back without a problem.

I have the same pot in one of my amps which also scratches between some points and it became slightly worse over time (during adjustment only)

replacing it is not as easy as it seems.
You need to have the correct pot (one with a switch) and to get it out you need to heat ALL contacts at the same time.
I do this by applying a huge amount of solder on all pins which one heats in one go (need at least 40W iron)
Once the solder melted GENTLY try to wiggle out the pot. Do NOT pull with force !
Then suck the holes open (solder gun or by heating the solder and while hot tapping the PCB on a table or de-solder braid.)
Another option is to heat the solder and blow it out with compressed air.

Both the table-tap and compressed air method create HOT solder splatter !

 

[DonH56]

I'd just get something like this: https://www.amazon.com/WEmake-WM-SP...t=&hvlocphy=9029015&hvtargid=pla-491294181333

I would not use compressed air to blow it out; seems dangerous. The table -tap method works great until a blob of solder flies unnoticed onto your pants. What follows shortly thereafter may be damaging to the board and other nearby objects.

 

[FrantzM]

The Atom is $99, a more than decent price for such a high performing product ... Did hey cut too many corners?

 

[Veri]

The Atom is $99, a more than decent price for such a high performing product ... Did hey cut too many corners?

I'm wondering if they will make a premium Atom. EL Amp should get a refresh now that Atom is out but that would be a mostly cosmetical: 'big knob' with engraving upgrade...

 

[EReich]

Hello to all. This is my first post and I found this forum because I was looking for a review for the THX 789. First of all thank you @amirm for putting in all this effort to provide very valuable information. I have to be honest, I barely understand any of the words @amirm use to measure all these audio equipment but thanks to his graphs which indicates (higher is better / lower is better) etc I can at least tell which is better than which. Back to the 789, I was able to get in on the last drop which is suppose to ship on August. I just bought the Atom yesterday because price isn't that bad and I couldn't wait till August to have a better audio experience. I have the schiit fulla 2 right now and to sum things up, I'm not happy with it. I just recently got into the desire of having better audio and have just built my first computer and moved passed using laptops for now and since it's on my desk I don't really need something portable at the moment. My current cans are M40s with ZMF cowhide pads, HD58x and Tin t2, t2 pro & t3 for IEMS. I don't know if I'm at a good start in going down this rabbit hole but they sound decent to me. But yeah I'm really looking forward to trying the Atom soon. It just shipped today

Pardon the long post, I'm just excited to be here and finally finding a place to hangout and find guidance for my audio needs. You guys are awesome.
English isn't my native language so I apologize for not being able to write a short and concise post.

This is my current humble setup.

 

[dweekie]

Just saw these semi-rigid cables on the JDS Labs site. I'm considering ordering a pair since my Atom likes to stand on its hind 2 legs with my current cables...

https://jdslabs.com/product/stack-rca-cables/

 

[amirm]

Pardon the long post, I'm just excited to be here and finally finding a place to hangout and find guidance for my audio needs.

Welcome and thanks for the kind words. Your setup looks great. Mine has so much junk around my monitor, you will never see a picture of it in public.