Uniti Atom - SSD vs USB stick SQ?

Hi, I’m new to the forum. I usually read the posts and try to find the answers to my questions. However, I cant find the answer so i though I’d ask.
Has anyone tried to see if there is a difference between using an SSD drive, vs a HDD, vs a USB stick for sound quality on the Uniti series?
Is there any hard and fast rule to this?
I tried a cd played from a cheap DVD player through the HDMI input last night on my Atom, and i think it sounded slightly better than the Samsung SSD i have loaded with all my music and plugged into the back.
I would appreciate any thoughts.
Cheers, Mark.

Hi Mark,

I have been playing with different types of sources on my Atom. Below you find a list of the sources I have tested, ordered from best to worst. That is what I found when testing this some time ago.

Music playing from (best to worst):

  1. External Hard Drive on Atom (have not tried SSD or USB stick)
  2. Qobuz on Atom
  3. TIDAL on Atom
  4. Roon
  5. NAS (Synology DS213+)

The difference between 1, 2, 3 and 4 were very small to my ears. Music from the NAS sounded worse compared to the other options. But this is relative, even playing from the NAS it sounded good enough. All devices are connected through Blue Jeans Ethernet cables.

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Yeah that’s in line with what I have found. If you try a Compact disc you will find it slightly better than a hard drive (even when played through a cheap DVD player).

My theory at the moment is that maybe taking away the cable from the drive might make a little difference.

Samsung do some nice high capacity USB sticks.

I’ll put an album on a smaller stick today and compare and I’ll let you know if there’s a difference.

Mmm, I’ve been pondering this rank ordering of things, too, (Often seems I do little else but hey. . .) and I was very impressed when I played a CD via a Sony UHD player into my Nova.

I’ve had numerous CD players and transport/DAC combos in the past and I was hoping I’d put physical disc players behind me, after all Qobuz and Tidal via Naim app or Roon sound great. As do my FLAC files served from my Innuos.

All that said, I was quite taken aback when I spun a disc in my cheap Sony player (kept solely for films etc),and for a few flickering minutes started to ponder a new transport. But then the reality of my last few lockdown months ripping 3,000 Cd and rising kicked in.
The Nova is meant to minimise my box count not re-start it.

My last decent transport/DAC was the Chord Blu/QBD76 and whilst it sounded fantastic going into some old Roksan Caspian amps they all gave way to other gear then along came the Nova.

What calibre of CD player or transport do others feed their Unitis with, if any at all?

Mines a cheapo Cambridge Audio Azur 550C via an optical cable into the back of my Nova and it sounds at least as good as the usb stick.

Mine is a sony bdp also… cheap as.
The convenience of the hard drive will always take precedence , however, it is a little disheartening to know that my crappy DVD player can do a little better.
There really isn’t much in it, what i heard was a little more meatiness to the sound without loss of detail or sparkle.

I’m rather on the bits-are-bits faction; so as long as the data arrives digitally in the memory of the Uniti, the sound will be produced in the internal DAC…
… but honestly, I haven’t bothered to test different input here to a larger extend.

For feeding ripped (and some downloaded) music to my Atom, I use a rather cheap external SSD.
Main reason was it was physically rather small, uses not much power (compared to some potentially very fast/powerful SSDs), is completely silent (as compared to a HDD), and it’s faster than most USB-Stick (though only about 150MByte/s; but I read, that fast USB3-sticks can get rather power hungry and warm - the SSD is always “cool”) on the rarer occasion, when I delta-copy new music over from my Mac.

Feel free to play with different types. If there’s nothing special you find, go for a good usability vs. size vs. cost compromise for yourself.
(I would discard HDDs (reliability, noise), unless you really need several TByte of data and don’t want to spend the money on respective SSDs.)

Question to the previous posts: when you use CD players, you feed then digitally into the Uniti, correct? Then, unless they produce overly jitterish or error-containing data feeds, their internal DACs etc. pp. should not matter. (As you comment on them being “cheap”.)

I guess it seems like people are almost disappointed that their cheap CD player sounds “as good” as the usb/ssd or whatever should be testament to how good the 40 bit Sharc processor in the Uniti range is at eliminating jitter and other nasties, effectively levelling the playing field in terms of sound regardless of input choice. Great news for us Uniti owners because it sounds great whatever.

Over the years I have heard a difference enough times to know that even a different digital cable can make a difference from the same device (e.g. optical vs coax), so i am sure a transport can make a difference (be it small). It may be that the signal is the same but is accompanied by less noise from the crappy power supply on cheaper devices.

On the contrary, i am well impressed. It just got me wondering if i can somehow get the same result from a USB drive/stick, so I wondered if anyone had done a comparison with different USB devices.

I would agree with your last statement. I have bought an iFi mains noise conditioner and it made a big difference on my CD player unlike the Nova via usb where I couldn’t discern any major change. Likely down to the quality of the power supply differences.

I absolutely love this Unity atom. I don’t seem to have the same fluctuating audio quality as i have read elsewhere, but i have wired a dedicated mains to my hifi system. Might be partly responsible. Also i have rather large, efficient speakers so i have awesome bass.

So was there a difference with the Nova at all when plugged into the power conditioner vs when plugged in the wall?

I’ve tried plugging it in different positions and from what I can tell it seems to affect the sound from the CD player more than the Nova directly.

Adeypoos, that’s really good info. Very much appreciated you may have just saved me a load of money.

I tried USB stick vs wired ssd yesterday but no difference at all.


You are right! I forgot to put the Cambridge Audio CXC on top of my list. :blush:

I tried various USB thumb, wired and SSD.

For me the Samsung SSD was better in SQ and heat.

Heat was the issue with every USB thumb drive, the really small SanDisk ones being the worst offender, but same issue with one connected to my TV.

How did the heat issue manifest itself(other than the fact it was hot)?