An update regarding the Sony PCM-M10's DAC
A very generous Head-Fi member who lives near me has loaned me some of his gear while he is on vacation. This includes an
April Music Stello DA100 DAC that I have had in my possession for about two weeks now.
I've spent about eight hours, thus far, comparing the following component chains:
44.1/16 and 96/24 WAV files > Sony PCM-M10 Line Out > Meier-Audio Corda Stepdance > Audez'e LCD-2
vs.
44.1/16 and 96/24 WAV files > Win7 laptop > USB > Stello DA100 > Meier-Audio Corda Stepdance > Audez'e LCD-2
Having copied to the laptop's hard drive, several WAV files from my PCM-M10's 32 GB microSD cards, I am able to hit "Play" on the laptop and on the Sony PCM-M10 to begin playback simultaneously, then I just swap the cables going to the Stepdance analog input jack so that I can jump back and forth from listening to the Stello DA100 DAC vs. the Sony PCM-M10 Line Out. I have also adjusted the volume level on the laptop to match that of the Sony PCM-M10 Line Out. This allows me to use the Stepdance volume control at will, impacting the two DACs equally as heard in the Audez'e LCD-2s.
Interestingly, both DACs are sigma-delta designs and the digital inputs of both can handle sampling rates no higher than 96kHz at a depth of 24 bits, but the Stello DA100 offers a 192kHz upsampling chip to provide a function not available with the Sony's DAC, with a switch to Bypass 192kHz upsampling, so that, if you prefer, you can hear the digital file converted to analog at its native sampling rate, be that 44.1, 48, 88.2, or 96kHz. The WAV files I'm using in this comparison are either 44.1 or 96 kHz.
Keep in mind, most people would agree that upsampling cannot possibly increase heard detail beyond that which was originally recorded. It's analogous to trying to use Photoshop to resize a 6 Megapixel image capture in hopes of getting it to compete with a 12 Megapixel capture. Sharpening tools can be used to improve the acutance (edge or boundary sharpness) of an upsampled image, but you will still have no actual increase in resolution of the original content. Continuing with the analogy, if a distant person's face is unrecognizable due to insufficient resolution in the original capture, they will still be unrecognizable after upsampling and sharpening.
Focusing my attention on recordings where there is a lot of intrinsic detail (soundtracks of "Inception" and "Tron Legacy", for example, and some classical and jazz pieces where there are a lot of voices that are difficult for a DAC to separate and image), my very first impression from perhaps 30 minutes of listening was that the Stello DA100 was retrieving a lot more information than the Sony's DAC. I even described the experience as a "revelation" in a thread where I posted about it at the time and the experience sent me immediately into considering the purchase of a 160GB iPod Classic + Cypher Labs AlgoRhythm Solo (perhaps the best truly portable DAC available) as a replacement (a very expensive replacement) for my Sony PCM-M10.
I now regret having posted those impressions of the Stello DA100, because I'm utterly convinced they were premature and based almost entirely on listening to the Stello DA100's 192kHz upsampling feature.
I've spent easily six full hours now, listening very critically, comparing the Stello DA100's 192kHz upsampling mode vs. its Bypass mode vs. the Sony PCM-M10 Line Out and early on concluded, and have continued in my conviction, that the 192kHz upsampling had initially infatuated me with something that was simply new to my ears, but which really doesn't offer more detail, transparency, accuracy, air, soundstage, or imaging than the Stello DA100's Bypass mode or, get this, than my Sony PCM-M10's Line Out!
I first came to this realization by just comparing the Stello's 192kHz upsampling mode to its own Bypass mode, across many tracks. You can't make a silk purse from a pig's ear. If the detail isn't there to begin with, making it
sharper doesn't reveal more detail. And that's the best word I can come up with to describe the difference between upsampling and bypass on the Stello DA100 - it's
sharper - more etched - much like a Photoshop image where edge contrast has been increased through use sharpening tools, but there is no real increase in resolved subject detail. I've come to find the upsampling fatiguing - it's unnaturally etched, where the Bypass mode sounds musical.
And having now spent several hours comparing the Stello's Bypass mode to the Sony PCM-M10's Line Out, where the analog side of the Stello's DAC is heard at the native resolution of the inputs I feed it, I'm convinced that I can hear only one trait which significantly (but not dramatically) betters the performance of the Sony PCM-M10's DAC: improved bass extension.
All that said, I must still say that that Stello DA100 seems to offer just a wee bit of a resolution advantage when listening to 96/24 WAV files in Bypass mode - it's not significant and I would say it's hard for me to discern in all but the most challenging signals - nothing like the difference I had thought I was hearing with my first exposure to the Stello using 192kHz upsampling - where I was smitten by its sparkle.
Though "sharper," the upsampling does nothing to improve separation of voices or instruments which sound like a homologous blob with lesser DACs. The upsampling also does nothing to expand the soundstage or focus the imaging. But it sugar coated my initial comparisons, nevertheless.
Conclusion:
The Sony PCM-M10's 96/24 DAC, as heard via Line Out to a Meier Corda Stepdance (famous for it's resolution and transparency) and Audez'e LCD-2 (even more revered for these same traits),
at least to my ears, offers something like 98% of the resolution and detail offered by the Stello DA100 DAC, with the Sony PCM-M10 falling short of the Stello DAC more significantly, but still only slightly, in the area of bass extension.
I'm far less interested than I was previously in replacing my $239.00 Sony PCM-M10 with nearly $1000.00 worth of iPod Classic + Cyber Labs AlgoRhythm Solo + interconnects. I'm still very interested in making that comparison, but haven't had the opportunity to do so. From what I've read, the Wolfson DAC in the Solo could put the Stello DA100 and PCM-M10 DAC's to shame.
Meanwhile, since no one has popped up out of nowhere offering to lend me their Classic + Solo, I have spent considerable time researching the inventories of various Head-Fi members (by studying their profiles) and have isolated a candidate to whom I have sent a PM suggesting he accept my offer to lend him my Sony PCM-M10 for comparison to his MANY different portable sources. This member has ALL the good stuff - iMod, Classic + Solo, HiFiMan 801, etc. and his posts have exhibited a particular interest in playing 96/24 files portably - which the iDevices can't do, due to their 48kHz limitation.
I just sent that invitation yesterday - no response as yet - but I can't wait to get the opinion of someone so well equipped and experienced as to the performance of the Sony PCM-M10 Line Out.
Stay tuned...
Mike
[Edited spelling and choice of words, in a couple of places.]