Saturday, 27 July 2013

MEASUREMENTS: DAC "Waveform Peeping" - the -90.3dB 16-bit LSB Test...


When it comes to technological "toys", I've vacillated over the years between the accumulation of digital photography gear and audio stuff... As I'm sure many of you know, "pixel peeping" is the act of "using 100% crops and similar techniques to identify flaws that have no effect on the photograph under real-world conditions" (Google web definition). Back in the "old" days (like a decade ago), the act of pixel peeping wasn't all that unreasonable since the differences visible could be demonstrated on photo-enlargements. When I was using my old Nikon D70 with 6 megapixels, sharpness at the pixel level was a significant consideration with moderate enlargements like 13"x19"; imperfections like moiré could be seen in the final product as well. Monitor resolution wasn't that high back then either so fine details were easily obscured.

Fast forward these days and I'm now using the Nikon D800. At 36 megapixels viewed on a >2MP monitor; unless I'm printing huge enlargements, there really is little need to "zoom" down into the 1:1 pixel level to appreciate a high quality image... Sure, sometimes it's just fun to see how much detail has been captured especially when evaluating different lenses or to show off each hair follicle, but for the most part, "pixel peeping" has become quite unnecessary.

Although in daily usage, one might not need to "peep" anymore, if one were to publish camera body or lens reviews, any reviewer these days "worth their salt" would run the images through objective tests; including highly detailed "pixel level" tests or compare 1:1 images between cameras or lenses. Dynamic range, ISO-noise interaction, color accuracy tests, distortion characteristics (for lenses), effect of file formats (JPEG vs. RAW) of course all serve to complete the evaluation. The quality is so high these days among high-end cameras (SLR's, medium format digital backs...), it is with these detailed tests that we can fully appreciate the qualitative differences between top contenders. Subjective opinions in terms of the camera's touch-and-feel and user interface are important of course, but if you care about the potential image quality that can be captured, then objective tests are really really important. If you haven't already done so, just have a look at the camera reviews on www.dpreview.com and see how much work actually goes into what I respect as proper reviews of well engineered equipment! Also of interest, Hasselblad is trying to market "exotic" cameras at high prices by appealing to aesthetics (just look at the responses to see how people feel about that!). [Here's another one.] Is this what happens when technology matures and companies have difficulty competing on primarily technological merits?

I've often wondered why in the audio world, objective measures have so often been left out as part of the review process - especially as it comes to line-level devices like DACs. Maybe it's because digital audio matured earlier and we're going to see the same outcome with cameras one day. Around some forums, the mere mention of objective measures seems to be scoffed at - as if objectivism with audio gear is either "obsolete" or the sole domain of "high end" manufacturers with arcane tests out of reach of mere mortals. I know I'm digressing into "MUSINGS" territory here, but IMO, a good review needs to dig into the gear's objective properties so the reader can truly appreciate how it compares with other similar gear in order to have an informed opinion and gauge value as a (hopefully) well engineered piece of technology... Let's get back on track then with some "MEASUREMENTS".

For me, one of the most interesting "waveform peeping" tests consistently done by Stereophile over the decades on digital gear has been the undithered 1kHz sine wave test at -90.3dBFS. This is one of the most "microscopic" tests of DAC performance. It's simple and the result basically answers the question "can this DAC accurately reproduce the least significant bit (LSB) in a 16-bit audio signal?" At a glance one can tell at least 3 things:
1. Is the DAC "bit-perfect" down to that last 16th bit? (Assuming everything upstream is set up properly, you should see something resembling the 3 quantization "steps".)
2. Is the dynamic range at least 16 bits? If not, the waveform becomes obscured by excessive noise.
3. Are there anomalies to the waveform morphology to suggest "DC shifts" leading to "tilting" of the waveforms (power supply related issues). (For a good example of 60Hz low frequency noise effect, see the measurement of the Philips CDR880 Figure 7.)

The Stereophile website archive provides some lovely examples of this test dating back to the late 1980's such as the Philips LHH1000 from 1989 (check out Figure 5). How about the Naim NA CDS from 1992 (Figure 6) or the $8000 Mark Levinson No.35 DAC from 1993 (Figure 6, still not good). By 1995, we saw excellent performance like with the $9000 Krell KPS-20i (Figure 5). In a few years, by 1998, reasonable priced gear like the California Audio Labs CL-15 CD player was capable of similar accuracy at the $1500 price point. Since the millennium, this level of performance can easily be achieved within the $1000 price point and below (eg. the Rega Apollo from 2006). These days, the little Audioquest Dragonfly can do a reasonable job USB-powered at <$250 retail.

On the whole, this test has demonstrated the progression of improved accuracy over the years. State-of-the-art DACs like the MSB Diamond DAC IV (Stereophile October 2012, not on website) and Weiss DAC202 (Figure 6) are great examples of what this level of accuracy looks like (as opposed to expensive gear of questionable technical ability which I will not mention). IMO, well engineered CD/DVD/SACD/Blu-Ray/DACs these days claiming to be "high resolution" really should pass this test without issue. Nonetheless, there are recent devices apparently incapable of a low noise floor for whatever reason (eg. Abbingdon DP-777 Figure 15, surprisingly the recent Wadia 121 Decoding Computer Figure 6 didn't fare too well either).

I was curious whether I could run a similar test using my simple test gear... After all, so long as the DAC and measurement device can achieve >16-bits dynamic range reliably, one should be able to obtain a reasonably good set of measurements. So far, from what I've seen in the other tests, I should be able to reproduce this test with the E-MU 0404USB!

Here goes... Setup and procedure for the various DACs/streamers:
Test DAC --> shielded RCA --> E-MU 0404USB ADC --> shielded USB --> Win8 laptop

- I created an undithered 1.1025kHz sine wave at -90.31dBFS at 16/44. This is what an "ideal" waveform would look like with the usual Gibbs phenomenon (ringing) due to bandwidth restriction.
- Green is LEFT channel, Blue is RIGHT channel. Notice the phase inversion between the channels.

- For comparison, I also created the equivalent at 24-bit quantization:

- Capture the above at 24/88 with Audacity using the E-MU 0404USB. From previous tests, the E-MU functions very well at 2x sample rates (88 & 96kHz) with optimal dynamic range. Although not as good as a high precision oscilloscope used by Stereophile, this should be adequate to allow relative comparisons between different DACs. I used the analogue preamp on the E-MU to boost the signal by about 18dB to give me "more" amplitude to capture.
- As you can see above, I decided to plot the channels overlaid and inverted to compare precision of timing and amplitude.

Here are the results of this test on the various DACs I have around here:

TEAC UD-501 [2x BB PCM1795 circa 2009] SHARP filter:
16-bit undithered:


24-bit:

Clearly the TEAC has no problem with reproducing that least significant bit in the 16-bit signal. Also, obviously the resolution has improved significantly by going to 24-bits.

ASUS XONAR Essence One [2x BB PCM1795 c. 2009] (opamps upgraded to all LM4562):

Very nice... Notice a wee bit of channel imbalance - the left channel (blue) seems consistently louder than the right. Same internal DAC chip as the TEAC so similar level of performance expected.

Logitech Squeezebox Transporter [AKM4396 c. 2004]:

Nice! Not bad for a discontinued device from a computer peripheral manufacturer released in 2006, eh? ;-)
Of course, the Stereophile review demonstrated this nicely already...

Logitech Squeezebox Touch [AKM4420 c. 2007]:
WiFi (only 30% signal strength 2 floors up from router!):

Ethernet:

24-bit:
Three observations:
1. Clearly the Touch is noisier than the better DACs above. It's still capable of >16-bit dynamic range though.
2. Some DC shift is evident - look at the upward slope with the 24-bit sine wave and compare to the Transporter above. Maybe this could be improved with a better linear power supply than the stock switching wallwart I used... Not sure if an improvement would be audible however.
3. No substantial difference between WiFi and Ethernet. (No surprise; just thought I'd have a look to see if WiFi added much noise down at this level.)
N.B. Remember that this is still a pretty good result - we are looking at a waveform down at -90dBFS, or ~90 microvolts! Nice correlation with what Stereophile found (Figures 5 & 6) in terms of the Touch being a 'touch' more noisy than better DACs.

AUNE X1 Mark I [BB PCM1793 c. 2003] (using CM6631A USB-to-Coaxial S/PDIF, ASIO driver):

This is what can be achieved by a <$175 DAC off eBay direct from China these days (I bought this unit in early 2012). Notice that it's able to produce a cleaner analogue output than the Touch. But it's also not quite up to the standard of the TEAC, ASUS, or Transporter. Notice both a slight channel imbalance as well as mild amplitude fluctuations (again, possibly due to cheap wallwart). Hopefully the following zoomed out screenshots illustrates this well for comparison:
 AUNE X1 - left channel (blue) noticeably louder and notice the amplitude fluctuations over time.

Touch - Notice it's more noisy with unpredictable amplitude spikes occurring in both right & left channels.

TEAC UD-501 - more stable, clean, uniform waveforms in comparison.

As much as it's great to see the level of performance afforded by DACs these days, I'm very impressed by the level of performance of this old E-MU ADC! As I have stated before, one of the reasons I put up these posts is to demonstrate that it doesn't take megabuck equipment to test out audio gear objectively. A lot can be "known" about the performance of a piece of hardware rather than depending on only subjective "opinion".

The other test I would categorize as the equivalent of "pixel peeping" is the Dunn jitter test where we're "peeping" into a small part of the audio spectrum around the 11 or 12kHz primary signal and scanning for sideband anomalies. IMO, neither the jitter nor this undithered LSB test really are that important for audio quality. Random noise affecting the 16-bit least significant bit would sound like some form of dither (eg. like what happens when an HDCD with embedded LSB data is decoded by a non-HDCD player). Likewise, my feeling is that even a "moderate" amount of S/PDIF jitter (like say 1ns) isn't going to intrude into my listening pleasure. (Maybe one could make the argument that the details and nuance of sound/music can reside in these microscopic domains but I have yet to see any proof...)

Assuming the digital player/DAC is meant to be faithful to the source signal and doesn't implement a DSP known to affect the LSB data, to be able to measure and verify precision down to these levels I believe would be a reasonable pre-requisite in achieving high-fidelity. It's a test of how well the hardware was designed and implemented than necessarily how it "sounds". Just like knowing if a hi-res digital camera is capable of the resolution it claims... You might never need 36 megapixels for a slideshow or in print, but it's good to know that the camera was capable of delivering on the claims! Likewise, if I'm going to spend a good amount of money on high-fidelity gear, I'd certainly like to know that precision engineering went into it by the results of tests like this among others already discussed over these months.

Let's throw some nostalgia in. Here's what the MUSE Mini TDA1543 x4 NOS DAC looks like down at -90dB (using the CM6631A USB-to-S/PDIF coaxial interface):

Party like it's 1991! Ugly... Clearly it's incapable of accurately reproducing the 16-bit LSB undithered tone.

Zoomed out (24/44) - still ugly:

Using a 24-bit signal makes no difference since this is a 16-bit DAC and the lower 8 bits get truncated. The Philips TDA1543 DAC chip was introduced back in 1991 according to the specs sheet... Thankfully, it looks like DAC designs have improved somewhat since then at least in this characterstic :-).

A stroll down memory lane... The top 3 highest grossing movies of 1991: Terminator 2, Robin Hood: Prince of Thieves, Disney's Beauty And The Beast. Top 3 songs (Billboard): (Everything I Do) I Do It For You, I Wanna Sex You Up, Gonna Make You Sweat (Everybody Dance Now). Hmmm...  Good year :-).

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Folks, much of the measurements above were done about 3 weeks ago but I'm putting this post up behind the "Great Firewall" while on vacation (hey, >10hr plane flight gave me plenty of time to do some writing!). I know a few people are trying to get hold of me by E-mail. Unfortunately my VPN + Outlook is a bit finicky so other than more important work related matters as I check the E-mail every few days, I will likely not be responding until mid-August.

Time to go enjoy some good food... And snap some pictures of course... :-)


BTW: For those interested in some light non-fiction summer reading, consider picking up Chuck Klosterman's "I Wear The Black Hat: Grappling With Villains". An enjoyable, thought provoking social commentary.

Friday, 12 July 2013

LIST: Suspected 44 or 48kHz PCM upsampled SACDs.

 The sentence says "supported by Japanese SACD manufacturer" (whatever that means!). An example of how the term SACD gets thrown around in cheap domestic and pirated Asian markets (this wasn't a true XRCD either)...

As I mentioned previously in my post on SACD (and DSD), there are a number of SACDs I have digitally ripped over the years that appear to be sourced from 44kHz PCM. This is of course the same sample rate as good ol' RedBook CD and therefore it's unlikely that these titles should sound any "better" than the CD release since the PCM-to-DSD conversion process will add some distortion to the original signal.

It's not difficult to detect these releases because of the "brickwall" loss of frequencies beyond 22kHz. Note that this list is of course unofficial and even though there's evidence that these come from 44 or 48kHz PCM, it's still possible they're from 24-bit data which could still be "hi-res".

An example of the 22kHz brickwall - Thelonious Monk's "Between The Devil And The Deep Blue Sea" off Straight, No Chaser SACD. Notice the typical ultrasonic 'noise shaped' SACD quantization noise from 22kHz up - filtered off in this case before 40kHz.

The reason I decided to post this list up was because even to this day, some folks will use questionable albums such as these to prop up the putative superiority of the SACD format or compare the DSD rip with the CD layer...  Even as recently as the May 2013 edition of Home Theater magazine - David Vaughn reviewing the Marantz AV8801 & MM8077 spoke of how he preferred the two-channel SACD layer of Norah Jones' Come Away With Me (p.41). There is of course one "inconvenient" problem; we've known since 2004 that this SACD was in fact a RedBook CD upsample! Therefore, the preference must be the result of perceptual bias, euphonic distortion by the DSD conversion, or maybe his SACD player is poor at playing CD. I have seen these kinds of comparisons and biases based on resampled SACDs made over the years both in the print magazines as well as on-line (eg. see this review) and in forums.

By no means do I believe this is a complete list - just ones I've run into over the years or confirmed by friends. I have tried to comment on these SACDs as part of my reviews on places like SA-CD.net but notice that these comments tend to get censored over time - I guess I can't blame them since they have something to sell :-).

Similar situations exist in the DVD-A world especially with upsampled 24/192 material (alas I never kept track of these but remember Frank Sinatra At The Sands was likely upsampled).

In alphabetical order of artists by common first names (threw in a few spectral screenshots):

Air Supply - The Definitive Collection (2003 SACD)

Al Di Meola - Consequence Of Chaos (2006 Telarc, multichannel mix looks good though)
From "San Marco"
Albert King - I'll Play The Blues For You (2004 release)

Albert King & Stevie Ray Vaughan - In Session (Probably 48kHz upsample, 2003)

Alison Krauss - Forget About It (2003 SACD, probably 48kHz upsample)
From "Maybe"
Alison Krauss - Now That I've Found You: A Collection (2002 release)
From "Baby, Now That I've Found You"
Andrea Bocelli - Andrea (2004 SACD, 48kHz source)

Andrew Lloyd Webber - The Phantom Of The Opera OST (2004 Joel Schumacher movie)

Antonio Carlos Jobim - The Composer of Desfinado, Plays (2011 SHM-SACD)
"O Morro"
Art Of Noise - Daft (2008 SACD release - both 2.0 and 5.1 look 44kHz sourced - what else to expect from 1980's synth/electronic!?)

Babatunde Olatunji - Circle of Drums (2005 Chesky Records)
From "Embracement"
Babyface - The Day (2001 SACD)

Baiba Skride - Bach Bartok Ysaye (2004 SACD)
From "Corrente - Partita No. 2"
Barb Jungr - Love Me Tender (2005 SACD 2.0 & 5.1; clearly 44kHz. Ahem... Linn, this sucks...)
From "Wooden Heart"
Benny Carter - Jazz Giant (2004)
From "Blue Lou"


Beoga - Live At Stockfisch Studio (2010)
From "Factory Girl"
Bill Evans - You Must Believe In Spring (2011 Japanese SHM-SACD)
From "Without A Song"
Bill Withers - Bill Withers' Greatest Hits (2016 MFSL SACD. Looks like 48kHz original.)

Billie Holiday - Body And Soul (2011 Analogue Productions SACD)
From "They Can't Take That Away From Me"
Blue Öyster Cult - Agent Of Fortune (2001 release, both stereo & multichannel layers likely from 44kHz)

Bon Jovi - This Left Feels Right (2004 SACD, 5.1 mix is OK!)
From "Bad Medicine"
Brooke Miller - Familiar (2012 SACD - as usual, Stockfisch SACDs originate from 44kHz sources. This one has an album DR9 so IMO it's easily good enough as 16/44 CD.)
From "You Can See Everything"
Bruno Walter & The Columbia Symphony Orchestra - Beethoven: Symphony No. 6 in F Minor "Pastorale" (1999 Sony release)
From "Thunderstorm, Allegro"
Bryan Ferry - Frantic (both stereo & multichannel layers likely from 44kHz)

Cat Stevens - Tea For The Tillerman (2011 Analogue Productions - surprising! Maybe 48kHz source)
From "Wild World"
Celine Dion - All The Way... A Decade of Song (2001 SACD) - both stereo & multichannel appear to be 44.1kHz sourced.
From "Beauty And The Beast"
Celine Dion - A New Day Has Come (2002 - no surprise with pop albums, maybe 48kHz source)

Charles Mingus - Supreme Jazz (Arizona, 1922 - Mexico, 1979) (2006 release by Membran Music. 44kHz samplerate both 2.0 and 5.1.) I believe the David Brubeck Supreme Jazz release is like this as well.

Chicago (Motion Picture Soundtrack) (2002 SACD - both 2.0 and 5.1 appear 44kHz upsampled)

Christian Schmitt & Bamberger Symphoniker - Charles-Marie Widor: Symphony for Organ & Orchestra Op. 42, Sinfonia Sacra Op. 81 (2009 SACD - both 2.0 and 5.0 look like 24/44)

Claire Martin & Richard Rodney Bennett - When Lights Are Low (2005 Linn SACD - both 2.0 and 5.1 frequency limited to ~20kHz)
From "My One & Only"
Count Basie - Live At The Sands (Before Frank) (2013 MFSL SACD Remaster)
From "I Can't Stop Loving You"
Cowboy Junkies - Whites Off Earth Now!! (MFSL 2006 release - originally PCM recording)

Dana Winner - Unforgettable Too (2002)

Dead Can Dance - MFSL SACD Box Set (2008)
From "The Carnival Is Over" on Into The Labyrinth
Dire Straits - Brothers In Arms (2005 release - well known PCM recording)
From "Money For Nothing"
Dire Straits - Brothers In Arms (2013 MFSL UDSACD 2099, no surprise)

Don McLean - American Pie (2016 SACD of 2003 remaster)
From "American Pie"
Donald Fagen - The Nightfly (2011 release - well known PCM recording, DVD-V version better IMO)

Duke Ellington & Count Basie - First Time! The Count Meets The Duke (1999 Sony SACD)
From "Battle Royal"
Duran Duran - Astronaut (2004 release - both 2.0 and 5.1 are 44kHz upsampled, no surprise for this pop album - an odd "mirroring" of frequencies is seen pivoting at 22kHz)
From "(Reach Up For The) Sunrise"
Elvis Presley - Elvis Is Back (2012 Analogue Productions - maybe so old there's no high frequencies!)

Enigma - MCMXC a.D. (2016 Virgin SACD - I'm guessing this was recorded at 44kHz.)
From "Principles of Lust"
eRa - The Very Best Of (2004 release, both 2.0 and 5.1 are 44kHz source)
From "Ameno"
Eric Bibb, Rory Block, Maria Muldaur - Sisters & Brothers (2004 Telarc - stereo mix is compressed DR9 as well - 16/44 good enough IMO, the 5.1 mix is better DR13.)
From "Give A Little More"
Eric Clapton - Journeyman (2014 Audio Fidelity AFZ 180 - being a 1989 album, likely recorded PCM in any case).
From "Running On Faith"
Eric Clapton & B.B. King - Riding With The King (2015 Audio Fidelity SACD - looks like 44kHz original source, was this way with the DVD-A as well back in the day. DR13 much better than previous DR9 though!)
From "Ten Long Years"
Eugene Ruffolo - Santa Sings The Blues (2009 release, Stockfisch)

Five For Fighting - America Town (2003 Release, both 2.0 & 5.1 at best 48kHz)
From "Superman (It's Not Easy)"
Fourplay - Energy (2008, probably 48kHz upsampled both 2.0 & 5.1, 2.0 layer is DR12 so still better mix than DR9 CD)

Free - Tons of Sobs (2014 Japanese SHM-SACD)
From "Wild Indian Woman"
Gloria Estefan - Greatest Hits (2002 Sony) - same DR as 1992 CD. Does have a multichannel mix however that looks like it came from higher quality source.
From "Conga"
Gloria Estefan - Alma Caribeña (2000 Sony)

Grover Washington, Jr. - Prime Cuts: The Columbia Years 1987-1999 (1999 SACD - looks like just 44kHz)

Harry Connick, Jr. - We Are In Love (2000 Sony)
From "Recipe For Love"
Heart - Alive In Seattle (2003 SACD, 2.0 looks 44kHz, 5.1 looks 48kHz)
From "Crazy On You"
Herbie Hancock - Gershwin's World (2004 Verve) - multichannel mix appears to be higher quality source.
From "Overture"
Indigo Girls - All That We Let In (2004 SACD - both 2.0 and 5.1 look like 48kHz. Stereo layer nasty DR7.)
From "Fill It Up Again"
Itzhak Perlman - Cinema Serenade (2015 Sony SACD, clearly 44kHz upsample - very dissappointed in this one!)

Jacques Loussier - Impressions On Chopin's Nocturnes (2004 Telarc) - says 24-bit PCM on box, looks like 44kHz both stereo & multichannel.

Jacques Loussier Trio - The Best of Play Bach (2004 Telarc) - says PCM on the box, looks like 48kHz surround and multichannel.
From "Toccata & Fugue in D Minor"
James Horner - Titanic OST (2003 SACD, both 2.0 and 5.1 sourced from 44kHz)
From "Leaving Port"
James Taylor - Hourglass - very disappointed by this one!
From "Gaia"
Jennifer Warnes - The Well (2003 SACD, probably 48kHz upsample)
From "The Well"
Joe Satriani - Engines Of Creation (2000)
     - Also, the CD layer has DR7 vs. SACD stereo layer with DR11.  Different mixes with very dynamically compressed CD layer!

John Eliot Gardiner & Philharmonia Orchestra - Grainger: The Warriors & Holst: The Planets (2003)

Keane - Hopes And Fears (2004 SACD - 2.0 layer looks like 48kHz and better DR master than CD release, 5.1 layer clearly 44kHz)

Keb' Mo' - Just Like You (2002 SACD - same DR as CD, 5.1 also looks like 44kHz upsample)
From 'Perpetual Blues Machine'
Keb' Mo' - The Door (2000 release)

Ken Ishiwata's Band - Marantz: Ken Ishiwata's 30th Anniversary (2009)

Kenny Loggins - Yesterday, Today, Tomorrow: The Greatest Hits
From "This Is It"
Ladysmith Black Mambazo - Long Walk To Freedom (2006 SACD, confirmed same DR6 master as the CD)
From "Homeless"
Ladysmith Black Mambazo - Raise Your Spirit Higher (2004 SACD)

Ladysmith Black Mambazo - Ilembe: Honoring Shaka Zulu (2008 SACD)

Lee Ann Womack - Greatest Hits (2004 SACD - looks like analogue tape conversion of music recorded in 44kHz for 2.0. Multichannel looks like 48kHz.)
From "You've Got To Talk To Me"
Los Lobos - Kiko (2014 MFSL SACD)
From "Arizona Skies"

Ludacris - Chicken -N- Beer (2003 SACD - at best 48kHz 2.0 and 5.1)

Mandelring Quartett - Mendelssohn Complete String Chamber Music Vol. 1 (Audite SACD, 2012)
From Track 3
Martin Taylor - Artistry (2004 Linn SACD) - looks like 44kHz source, multichannel similar.
From 'Georgia On My Mind'
Martin Taylor - Spirit of Django (2004 Linn SACD) - looks like 44kHz source, multichannel similar.
From 'Nuages'
Martin Taylor - Masterpiece Guitars (2003 Japanese SACD)
From 'Thank Heaven For Little Girls'
McCoy Tyner Quartet - New York Reunion (2007 Chesky Records SACD) - a very bizarre mix of 44.1kHz and analogue. Certain songs like track 3 "What Is This Thing Called Love" just 44.kHz upsampled. In any event, dither to 16-bits, not worth 24-bits due to noise floor.

Michael Bolton - Greatest Hits 1985-1995 (2001 Sony/Columbia SACD - no surprise; DR8 so IMO never needed 24-bit anyway!)
From 'That's What Love Is All About'
Michael McDonald - Motown (2003 - both stereo & multichannel 44kHz, DVD-A probably more accurate)

Michael McDonald - Motown 2 (2004)

Mike Stern - These Times (2004 - stereo looks like a 16/44 with DR9, multichannel 48kHz)

Miles Davis - Seven Steps To Heaven (2010 Analogue Productions release, 3.0 multichannel track looks OK though!)
From "Basin Street Blues"
Miles Davis - Sorcerer (2014 MFSL UDSACD  2145, some tracks like "Limbo" appear to be 44kHz source in parts)

Monty Alexander - Monty Meets Sly and Robbie (2000 Telarc SACD - both stereo and multichannel look like 48kHz source)

Moya Brennan - Two Horizons (2003 SACD. 2.0 layer is same as CD. 5.1 layer 48kHz.)

Nancy Sinatra - Super Audio Best (2011 Japanese SACD release) - noisy and 22kHz limited - might as well convert to 16/44.

Nat King Cole - Welcome To The Club (2013 Audio Fidelity)
From "The Blues Don't Care"
Nick Drake - A Treasury (2004)

Nicki Parrott - Moon River (2014 Japanese SACD, only DR8 - keep it 16/44!)

Nikolaus Harnoncourt, Arnold Schoenberg Chor & Concentus Musicus Wien - Handel Messiah (Deutsche Harmonia Mundi 2005 SACD) - both 2.0 & multichannel upsampled.
From "Air Ev'ry Valley Shall Be Exalted" (CD1)
Norah Jones - Come Away With Me (2003) [for completeness, there is a 2012 Analogue Productions SACD remaster with proper non-44kHz-derived stereo layer.]

Original Broadway Cast - A Chorus Line (1998 SACD)
From "Nothing"
Oscar Peterson Trio - We Get Requests (2011 Analogue Productions) - both stereo and 3.0 multichannel look to be either 44.1/48kHz source.
From "Have You Met Miss Jones?"
Patricia Barber - Café Blue (2002 MFSL UDSACD 2002) - remarkable reviews on the net on this SACD! If this was a digital recording from 1994, one would also wonder about the capabilities of the ADC.
"Nardis"
Patricia Barber - A Distortion Of Love (2013 MFSL UDSACD 2100)
"Parts Parallels"
Patricia Barber - Modern Cool (2002 MFSL UDSACD 2003)

Peter Gabriel - So (2003 release - I suspect 44kHz recording but transferred from magnetic tape to DSD, thus the tape bias in the high frequencies and higher noise)
"Sledgehammer"
Peter Gabriel - Up (2003 release)

Peter Tosh - Legalize It (2002 Sony). Multichannel track looks like a 48kHz source.
From "Legalize It"
Pixies - Bassanova (2008 MFSL)

Poncho Sanchez - Conga Blue (2003 Release, multichannel looks good)
From "Conga Blue"
Ricky Martin - Sound Loaded (was there ever any doubt!?)
"She Bangs"
Roger Waters - The Wall: Live In Berlin (2-disk, 2003 SACD - stereo version looks like 44kHz, multichannel version 48kHz)

Rush - Presto (2014 Audio Fidelity SACD... Likely recorded in 44kHz in 1989.)
From "Show Don't Tell"
Ryan Adams - Rock N Roll (stereo layer looks sourced from 44kHz, multichannel mix seems OK)

Sam Cooke - Ain't That Good News (2003 SACD)
From "Tennessee Waltz"
Sarah Brightman - Eden (both stereo & multichannel, stereo layer DR7 seems even more dynamically compressed than CD DR8)

Sarah Brightman - La Luna (like above, stereo SACD layer DR8 vs. CD layer DR9)

Sarah Brightman & The London Symphony Orchestra - Time To Say Goodbye (2004 SACD. Stereo DR7, multichannel DR9. Both look like 48kHz source. Probably no point keeping 24-bits due to poor DR.)
From "Time To Say Goodbye"
Sennheiser HD 800 Experience (2009 Stockfisch - isn't it bizarre that an audiophile demo SACD should be sourced from 44kHz material!?)
From Steve Strauss - "Closer"
Shirley Horn - Here's To Life (2004 Verve SACD, multichannel mix looks good though)
From "How Am I To Know"
Simon Rattle, Libera & Berliner Philharmoniker - Tchaikovsky: The Nutcracker (2010)

Spyro Gyra - In Modern Times (2001 SACD release - 44kHz upsample both 2.0 & 5.1, the original HDTracks 24/96 was upsampled 44kHz as well)
From "Feelin' Fine"
Spyro Gyra - Wrapped In A Dream (2006 SACD release - looks like 48kHz both 2.0 & multichannel)

Spyro Gyra - Original Cinema (2.0 appears to be 44kHz but better master than CD [DR12 vs. DR8], 5.1 looks good though)
From "Bump It Up"
Steve Strauss - Just Like Love (2005, Stockfisch's usual 44kHz recordings)
From "Closer"

Suitcase Pimps - Love Is Grand (2003)

Tears For Fears - Songs From The Big Chair (2014 SHM-SACD, I suspect it's a PCM recording source)
From "Head Over Heels"
The Allman Brothers Band - At Fillmore East (2015 MoFi SACD remaster!)
From "Stormy Monday"
The Dave Brubeck Quartet - Time Out (Columbia/Legacy & 2000 SME Japanese stereo layers)
     - Note the multichannel Columbia/Legacy layer seems to be OK.
From "Take Five" original Columbia/Legacy SACD.
The Gadd Gang (Steve Gadd) - The Gadd Gang (2008 Japanese release. Both 2.0 and 5.1 versions appear to be 44kHz sourced.)

The InTime Quintet & Tampere Philharmonic Orchestra - Piazzolla In Time (2004) - both 2.0 and 5.0 look like 44kHz upsamples.
From "Imperial"
The Police - Synchronicity (2016 SHM-SACD, was this album recorded in digital?)
From "Synchronicity"
 Thelonious Monk - Straight, No Chaser (1999 release, see image above)

Toby Keith - Shock'N Y'All (2004 SACD, both 2.0 and 5.1 appear to be 48kHz source)
From "I Love This Bar"
Tony Bennett - Playin' With My Friends (2001 release)

Tony Bennett & k.d. lang - A Wonderful World (2002 release, both stereo & multichannel from 44kHz)
From "La Vie en Rose"
Tower Of Power - Soul Vaccination [Live] (1999 Release - another example where the mastering better on SACD with DR11 vs. DR7 for the CD)
From "Willin' To Learn"
Uriah Heep - Magic Night (2004)

Vanessa-Mae - The Violin Player (2004 SACD - appears to be 24/48 at best both stereo & multichannel)

Vangelis - Blade Runner Soundtrack (2013 Audio Fidelity SACD) - I suspect the original recording was done in 44.1kHz.
From "Wait For Me"
Valery Gergiev & Kirov Orchestra - Shostakovich Symphonies No. 5 & 9 (2003 SACD - 2.0 track looks 44kHz, 5.1 track maybe 48kHz)

Various - Natural Jazz Recordings (30th Anniversary Fone Records SACD130 from NativeDSD.com, this is interesting, I tested the 1st 3 tracks and they all looked 44/48kHz upsampled.)
Josh Sklair "Beyond Words"

Vince Guaraldi Trio - A Boy Named Charlie Brown (2004 release, 48kHz source?)

Vince Guaraldi Trio - A Charlie Brown Christmas (2003 release)

Waylon Jennings - Analog Pearls Vol. 1 (2014 Stockfisch SACD, old analog recording, why release an SACD like this in 2014?!)
From "River Boy"
Wishbone Ash - Almighty Blues London & Beyond (2004)

Yo-Yo Ma, Edgar Meyer & Mark O'Connor - Appalachian Journey (2000)

Yo-Yo Ma - Soul Of The Tango (2003 release)

Zoot Sims - Zoot Sims And The Gershwin Brothers (2003 Release, looks like 48kHz upsample)

Zucchero "Sugar" Fornaciari - Blue's (2004 SACD - DR9 compression and no better than 16/44 for both 2.0 and 5.1! Original 1987 CD was DR13 BTW.)

Zucchero "Sugar" Fornaciari - Rispetto (2004 SACD - DR6 dynamic compression, no better than 16/44. 5.1 track looks like DSP-derived "virtual surround". Just awful release.)

Interesting how the list includes "audiophile" labels and even demo/promo material like the Ken Ishiwata Marantz SACD, MFSL, Linn, even Japanese SHM-SACD. I think it also doesn't help the SACD cause that early Sony SACDs like the Brubeck and Monk are among these. I estimate about a quarter of the SACDs I've had a chance to evaluate consisting of eclectic rock, classical, and jazz disks are of the suspected-44/48kHz-upsampled variety.

Remember that I'm not saying these SACDs are bad sounding, just that in principle, the CD layer could be a more accurate representation of the music since there's no PCM-DSD conversion going on. In fact, many of these sound great and suggests that CD quality may be good enough. Unless there's a multichannel mix that you want on these disks or the mastering is somehow different (eg. less dynamic compression), IMO, there's no point paying extra for these SACDs.

Feel free to drop me a note if you know more about the releases (eg. can confirm if 24-bit source) or if you know of other upsampled disks.

Musical selection tonight: On an 80's kick right now. Going to have a re-listen to Midnight Oil's Diesel And Dust to get into the weekend mood... First pressing from 1987 of course. :-)