I named the S.M.S.L D300 DAC my current King of Budget Esoterica. It sounds way, way better than just another one in a line of nice budget kit, as long as certain conditions are met. Rather than re-hash all of that, I encourage you to click here and check my review if you have not already done so.
The issue isn't with my ears. I can hear just fine even as I approach 50 years. Not that it helps with reviewing audio equipment, it can't hurt that I am a classically educated college level musician with perfect pitch. It's nothing to me to notice overtones, also known as harmonics, both what should be natural to the music, and what is 'added' as harmonic distortion by the 'bad, bad' equipment. I never have really understood the aversion to harmonic distortion. It's, well, HARMONIC. The first harmonic is the fundamental, the second harmonic is the Octave, which means its the exact same note just twice the frequency rate. The 'mean old nasty' third harmonic? Its a perfect fifth above the second harmonic, and therefore is also consonant with the fundamental.. they call it perfect for a reason. Fourth harmonic? Its a perfect fourth. Which guess what? Is the exact same note as the fundamental and the second harmonic! The are all climbing in an octave sequence. Yes, I get that equipment that adds or accentuates these things MAY not represent the musical performance accurately. But I also 'get' that I LOVE the way music sounds on tube amplifiers. I have NO technical or scientific argument or treatise to give you on what makes for the best musical reproduction. All I know is I know what I like when I hear it. It stands out from amongst all kinds of 'copy cats' in a saturated market.
You know what else I like? I am about to welcome you into the cognitive dissonance in which I daily live. I like to know what my hardware is doing on the electronic level. Measurements mean things to me. Surprisingly, they are important. I mean, we have to have SOME BASIC standards, right? I think we passed those benchmarks a long time ago actually, and the crazy low noise and distortion stuff out there is way past our ear's resolution. Yet no one is suddenly claiming digital audio is cured of all its 'digititis'. No one, except maybe a few of that same old cult are proclaiming perfect audio. Same guys who have been yelling 'bits are bits' since the CD hit the scene. (Reminds me of an episode from back in the early 90's when a friend of mine insisted that CD was the thing of the past.. DAT was the real deal and the future... I will let you laugh and clear before we move on. )
So what is my problem?? I am obviously talking about the S.M.S.L D300 DAC. Its PCM measurements are impeccable and it doesn't sound in any way clinical or digital; it frankly sounds amazing.
The PROBLEM came when I started seeing the DSD measurements. The DSD filters are very low, and very slow and gentle. All good so far for the DSD crowd, like me, who wants gentle filters to maximize transient performance and minimize ringing. DSD should be different than PCM. Many DACs just make DSD as much like PCM as possible without actually saying that to the buying public in order to quietly deal with its major issue... all that ultrasonic noise. Ummm... THAT is where we run into the problem with the S.M.S.L D300. Something is off with the analog stage.
The numbers not only are worse than their PCM equivalents, as we go up in oversampling speed, they get much worse. Certain websites would be panning this thing with trophies that have missing parts.
My best guess is the issue is in the secondary analog filter that should come after the initial FIR conversion filter. For instance, iFi has their DSD FIR filter converter followed by a RC analog filter at 80khz to keep the DSD time domain superiority intact while dealing with the remaining ultrasonic noise in a way that adds no new ringing at all, and maintains the signal to noise ratio and harmonic distortion at levels that match its PCM performance. Same with pretty much every other 'native' DSD DAC I have sitting around.
But not this S.MS.L. And damned if it defies the measurements and still sounds amazing anyway, especially at the 'sweet spot' I identified.
What would normally be sacrilege for a 'purist' like me, I caved and am oversampling everything to DSD256 and have chosen to set the filter at 104khz. And it sounds GLORIOUS. And it sounds about as good, as anything I have, including the RME ADI-2 PRO FS R BLACK EDITION in DSD Bypass mode, which not only sounds great, it measures the part. The only native DSD kit I have that really kindof makes quick work of the S.M.S.L is my Signalyst DSC2 discrete DSD converter build, which ironically really doesn't measure that well either since it uses good ol' fashioned transformer outputs like the good ol' tube days.
So with my rant over and my cognitive dissonance as active as ever, I will share with you what the DSD measurements from the S.M.S.L look like on paper. These tests are done either with Multitone's internal modulator that converts all its test tones to DSD, or they are DSD tones tones made by HQPlayer played back via external sources. ADC in use as always is the E1DA Cosmos, so we are in good technical hands here I assure you. Allright.. on with the show.
The rest I will present to you below, so you can see the changes the mostly unseen ultrasonic noise makes inside the 20hz to 20khz band.
I reiterate as bad as some of this might look, it still sounds, well, pretty darn good. There is NEVER anything audible in the noise floor. Never any noted artifacts. Never any noteworthy distortions.
What I believe I CAN surmise that is happening here.... truly excellent time domain performance. Likely very little digital ringing from filters, harmonic distortion that is innocuous or even pleasing to the ear. Masking effects that keep any other nasties or idle tones from being a problem.
And now? I am going to continue to enjoy listening to this merely $400 DAC that has engrossed me with some of the best DSD playback I have heard for the last two hours I have been writing this Blog entry, while I hope you enjoy going through the remaining graphs in the gallery.
Thank you so much for taking time to read my small corner of the interweb here at EUPHONICREVIEW.COM