MEASUREMENTS: Separate vs. AV Receivers (Emotiva XSP-1 vs. Denon AVR-3802 vs. Onkyo TX-NR1009) as Analogue Preamp.

Okay, so maybe I'm being a bit too dramatic using that epic battle between Godzilla and Rodan above :-).

With the recent acquisition of the Emotiva XSP-1, I wanted to see just how well a separate pre-amp with audiophile design in mind stacks up against something more ubiquitous like the AV receivers out there. Remember that a preamp at its core has very basic functionality - it allows switching of the source and volume control by adjusting voltage gain on the output. The essential difference between a good preamp versus poor one (beyond features, ergonomics, remote control quality, etc...) is how well it maintains a high signal-to-noise ratio (SNR). If you supply a high resolution line level DAC output, you want to see that signal come out of the preamp with as much resolution as possible; this demands that the preamp introduce as little noise as possible.

Is there good evidence that spending money on a good analogue preamp will result in more accurate music reproduction? Let's find out in this installment...

First, let me introduce the contenders today:

Emotiva XSP-1:

Currently the highest quality Emotiva preamp out. The claim to fame is the differential design for balanced operation. It provides 2 balanced inputs along with a host of unbalanced RCAs. Volume control is through a digitally controlled, analogue resistor network. For this test, I will not be using the analogue bass management or tone controls that could affect signal presentation / quality. SNR for this device is rated at >110dB across the board for both RCA and XLR operation.

Denon AVR-3802:
A 7.1 channel "classic" from the decade when SACD and DVD-A were starting life and home theater lovers started seriously investing in discreet surround receivers with Dolby Digital and DTS (as opposed to the matrix surround of previous Dolby Pro Logic receivers). Analogue 7.1 channels input available. I bought this unit back in early 2002. Though not the highest end back then, it wasn't cheap (I think I paid almost $2000CAD). I don't remember the results of actual 3rd party testing but the rated amplifier power is 105W into 2 channels at 8ohms with 0.05%THD.

Analogue input SNR is rated at (only) ~86dB based on the table in the manual. For the sake of measuring the best possible audio output, all measurements will be performed through the CD input in "DIRECT" mode which bypasses all processing including tone controls and bass management. Measurement will be off the front (stereo) channels of the 7.1 "pre-out" analogue outputs.

ONKYO TX-NR1009:

My new receiver mentioned in the previous post. Capable of 9.2 channels processing with 7.1 analogue external inputs. Again, not the most expensive in the Onkyo line but certainly in the upper end of the previous generation released in mid-2011. Amplifier is capable of more power than the Denon with a rating of 135W into 2 channels at 8ohms with 0.08%THD. Sound & Vision measured it as 145W into 2 channels at 8ohms with 0.1% distortion. Line level SNR rated at 110dB.

I'll measure it through the analogue CD input in "Pure Audio" mode where all extraneous audio processing is turned off. Likewise, it's supposed to quiet the video circuitry and even the front LED indicators and display are turned off. I will measure from the front (stereo) channels of the 9.1 "pre-out" analogue output.

Firmware was updated to the latest version as of September 2013 - 1131-1399-0211-4108.

Setup:

 

First, I just want to discuss the general setup. The main thing I wanted to know was just how much resolution was maintained with the signal going through the preamp and look/listen to the results through a variety of levels standard across each device.

For the TEAC UD-501 DAC at 24/96 (which to me is the sweet spot) using the "SHARP" digital filter measured the following way:

HTPC (AMD A10 "Trinity") --> shielded USB (Belkin gold) --> TEAC UD-501 --> shielded RCA --> E-MU 0404USB --> shielded USB -->  Win8 laptop

we get these results:

The hope of course is that when we pass the above signal through the pre-amp, there will be minimal loss in resolution (noise level remains low around -113dB, and no change to frequency response to suggest "coloration" of the sound). In my previous TEAC measurements, I noted that the XLR output was too "hot" for the E-MU 0404USB without volume attenuation which drops the resolution. My guess would be that the noise level drops to less than -116dB. I will measure the XLR output from the Emotiva XSP-1 and see (it's the only device out of the 3 capable of balanced operation).

 

Using the digital oscilloscope, I found the following correlation between peak voltage output from each preamp device (accurate to <0.05V) and the volume control setting (using the TEAC RCA or XLR input of course):

Nice to see the volume control accuracy of each device - every halving of output peak voltage corresponds with a 6dB decline of the volume "knob". Notice that the Emotiva and Denon are using a relative system of volume control (dB below 0dBFS) and the ONKYO is set to an "absolute" measure between 0 to 100.

The setup incorporating the pre-amp in-line therefore looks like this:
HTPC (AMD A10 "Trinity") --> shielded USB (Belkin gold) --> TEAC UD-501 --> shielded RCA/XLR --> Pre-Amp device --> shielded RCA/XLR --> E-MU 0404USB --> shielded USB -->  Win8 laptop

Results:

I. Emotiva XSP-1 RCA:

Without further ado, here is what the Emotiva looks like with the unbalanced RCA setup:

Frequency Response

Dynamic Range

This looks really good. At 2V peak output, the dynamic range at 111dB is very close to the "ideal" (113dB directly from the TEAC). Notice a very small amount of roll-off in the high end when using the Emotiva. Also as expected, when the volume is reduced (2V --> 1V --> 500mV --> 250mV), the signal-to-noise ratio goes down and we see a concomitant reduction in the dynamic range and rise in noise level.

II. Emotiva XSP-1 XLR:

Let's have a look at the XSP-1 operating in a balanced configuration:

Frequency Response

Dynamic Range

Well folks, proof that if you want absolute fidelity, you really need to squeeze out those last few dB's down below 110dB with balanced XLR cables! Irrespective of whether you can hear it or not :-)!

Seriously, these are some fantastic measurements. As I said previously, unfortunately, I don't have direct measurements for the TEAC's XLR output. When passing the XLR output from the TEAC to the Emotiva pre-amp, the results at 2V peak volume coming out of the Emotiva slightly exceeds the direct RCA output from the TEAC DAC across the board from noise level to distortion levels to even lower stereo crosstalk.

The high frequency roll-off is less than with RCA. Notice just how clean the dynamic range graph looks as well through XLR cables. Fantastic.

III. Denon AVR-3802 RCA

Now we get into the AV receivers:

Frequency Response

Dynamic Range

Remember, I am measuring the Denon in "DIRECT" mode with all audio processing including bass management turned off (front stereo speakers set to "Large" for the sake of completeness). Not unexpectedly, these results are clearly a step down from the Emotive XSP-1. With a dynamic range of ~96dB at 2V, the Denon is capable of passing through 16-bit CD resolution but nothing more.

Roll-off above 20kHz is similar to the Emotiva's unbalanced mode but worse than the Emotiva below 100Hz with a -1dB bass roll-off at 20Hz.

IV. ONKYO TX-NR1009

Finally, let us have a look at what approximately a decade of advancement (between this and the Denon) in AV receiver technology can do:

Frequency Response

Dynamic Range

With the ONKYO in "Pure Audio" mode, no video processing at all, HDMI and video inputs all disconnected... Wow! That's very impressive IMO for a machine that's a "jack of all trades". In fact, these results are almost the same as the Emotiva XSP-1 functioning in unbalanced mode!

As excited as I am about those results above, a modern AV receiver is meant to process HDMI and be connected to a TV. This receiver has a HDMI "passthrough" which is essentially always in operation and for most people, it would not be left in "Pure Audio" mode with all the video gear disconnected. As such, look what happens when I connect my LG 55LW5600 TV (55" passive 3D, LED TV from 2011) to the ONKYO and repeated the measurements:

Frequency Response

Dynamic Range

Ugly, my friends... Clearly having the TV HDMI connected has injected very significant amount of noise in the system! Dynamic range has dropped to ~80dB across the board (equivalent to 13-bits). Notice a very strong 60Hz mains hum which is even showing up in the frequency response graph... What is happening here is that I'm seeing the effect of ground loops. There are ways to overcome this of course. For example, using a 3-to-2 prong adapter to disconnect the TEAC DAC from ground resulted in the following:

Frequency Response

Dynamic Range

About 10dB improvement just by doing this. For now, I'm not going to bother isolating the problem further (I'll be moving house in about a month!) but suffice it to say that in a receiver setup with complex component interconnections, be very careful of noise polluting the analogue output as demonstrated above. Ground loops are very common especially with TV systems where ethernet and coaxial cables are often connected to the TV/receiver creating a number of potential ground points beyond the individual device plug-ins to the wall.

Summary:

 

So there you have it. The Emotiva XSP-1 measures as a very capable pre-amp unit with excellent resolution especially when used in a balanced configuration. There was barely any loss through RCA and the XLR performance is beyond the E-MU 0404USB's measurement capabilities. Note that in all these tests, I'm just using generic "Radio Shack" type RCA connectors and the XLR cables are inexpensive Monoprice brand. No reason for spending money on expensive cables when these kinds of results can be obtained with standard decent interconnects.

In "Pure Audio" mode without the HDMI system connected, the ONKYO performed excellently. It bested the 12-year old Denon AVR-3802 handily and is essentially neck-and-neck with the Emotiva in an unbalanced configuration. However, beware of the potential noise pollution and ground loops once you plug in all sorts of things into these receivers (like your fancy big screen TV)!

A little while back, I spoke about how music sounded better through the Emotiva XSP-1 compared to using the Denon as pre-amp. These results are supportive of my subjective impressions (I'm showing >10dB dynamic range difference and bass roll-off differences between the two). As for the ONKYO, it does sound much like the Emotiva as a stand alone audio device. Since I will be listening primarily with the ONKYO as a HDMI DAC (either from the computer or through Blu-ray player), for me the digital audio performance is much more important than the results I show here from the analogue input.

Music this evening:
My kids enjoyed Les Misérables (the movie) and really love to listen to it in the car on the way to school... My favorite recording of this is the recent 25th anniversary UK Tour cast from 2010's performance called "Les Misérables Live!" - certainly much better singing than Hugh Jackman and Russell Crowe!

I've got another trip coming up at the beginning of November and then the house move by the end of November. I hope to put up some results of the ONKYO as HDMI DAC before I go. Until next time... Enjoy the tunes...

ONKYO TX-NR1009 In The House...

Happy Canadian Thanksgiving long weekend everyone! Sadly we don't have the same "Black Friday" deals you lucky Americans enjoy :-).

I realized something the other day... I refuse to be deprived of Dolby TrueHD and DTS-HD Master Audio (MA) in the new home theater / sound room! These are of course the "new" (DTS-HD MA announced back in 2004, TrueHD in 2005) lossless surround formats available on Blu-rays. Furthermore, I want to finally be able to play multichannel FLAC files created from DVD-A and SACD rips, of which I probably have about 100 albums archived away on my music server waiting for the day I can get a decent multichannel DAC (the recent USB exaSound e28 looks interesting). There is only one reasonable and relatively inexpensive way at this time - embrace the HDMI interface.

Two options: either get a new surround processor like the Emotiva UMC-200 and use the external inputs of the Denon AVR-3802 for amplification purposes, or just upgrade the receiver to something (much) more modern since the AVR-3802 was bought at a time before adoption of HDMI (way back in 2002!).

After much humming and hawing, I decided to have a look at the used market locally. Fortuitously, a minty 1.5 year old ONKYO TX-NR1009 was available at an excellent price! The reviews (here and here) were good and the features and build looked fantastic so I decided to plunk down some cash for this baby:

A multitude of I/O ports and connectors. I doubt I'd ever touch composite, S-Video, and component analogue inputs again!

Now this specific model was released a couple years ago - it came out in mid-2011. It's "THX Select2 Plus" certified, capable of 9.2 surround, has 9 amplifier channels (potential for passive biamping the front speakers), all the usual digital sound decoding capabilities from Dolby and DTS along with 7.1 LPCM from HDMI up to 24/192, Audyssey MultEQ XT and the capabilities of HDMI 1.4 for video (3D, 4K upscaling). This model has since been superseded by the TX-NR929 (I would have thought the TX-NR1010 would have filled this role based on model number but the NR1010 actually has 7 amplifier channels, rather, the TX-NR3010 is the higher end model with 9 channels). In any case, it looks like the newer 2013 generation has Audyssey MultEQ XT32 (note the extra "32"; more and higher resolution room EQ control), built-in WiFi and Bluetooth, AirPlay, and 4K passthrough - cool but not essential for my purposes. Compared to the stereo audiophile world where we argue about the audibility of PCM vs. DSD vs. minute differences between digital filters, the home theater domain brings with it more features than most music lovers would likely care to know... I suspect that as the technology continues to mature in the future, we will see stabilization of feature set and the need for upgrades will diminish for most end users; if this has not already started.

Speaking of the future, 4K video is on the horizon though its mainstream commercial appeal is far from clear. I wonder if the consumer digital video world will play out like audio - 1080P becomes like the "CD standard" and 4K takes the role of SACD/DVD-A/hi-res downloads. The 4K image improvements can clearly be demonstrated (go have a look at a 4K TV near you), but other than videophiles and those with >60" screens, it's going to be hard to justify the improvement for most TV sizes, at most viewing distances. Also, there's currently precious little media out (the Sony XBR TV I saw comes with a Sony PC loaded with some sample material). A new Blu-Ray standard needs to be formalized (see recent news about 100GB 3-layer BD). It's also unclear whether current Blu-Ray players can read these >2 layer disks; even if they can be read, I suspect the players might need H.265/HEVC decoding which likely means brand new hardware. One area I can see 4K could be beneficial to smaller screens is in synergy with passive 3D giving a full 1080P image per eye without the drawbacks of active 3D glasses (I've been using a 55" LG passive 3D TV now for 2 years so can attest to the resolution limitations)... However, 3D movies have not taken the world by storm so I'm not betting on this to fuel sales :-).

I digress... Back to the ONKYO and sound... So far, I've plugged in my HTPC to try out the HDMI input - sounds great off the AMD A10-5800K "Trinity" computer for both music and movies; nicely detailed and dynamic. Multichannel SACDs sound great (DSD converted to multichannel FLAC played back with JRiver). Technically the amplifier portion does have more power than the Denon AVR-3802 with decent measured wattage even with 5 and 7 channels driven. With all DSP off and in "Pure Audio" mode, it's more "weighty" than my old Denon regarding bass impact; less "forward" sounding. It actually sounds closer to my recollection of the Simaudio Moon i3.3 integrated amp but that's of course from memory which we all know could be inaccurate.

Anyhow, I'll try to run a few measurements on this machine in the next while when I have some time. I'd certainly be very curious what the numbers/graphs look like compared to other DACs tested so far. According to the spec sheet, the DAC consist of an 8-channel TI PCM1690 and stereo TI PCM1789; both with rated SNR of 113dB - I'd certainly like to see if they can achieve anything close to this in a compact full-featured box with all the digital processing going on plus 9 power amplifier sections! This would also be the first time I'll have the opportunity to have an objective glimpse at performance off a recent HDMI implementation.

Onkyo tattoos!

BTW: Even though the ONKYO will be the heart of the surround system, I still have the Emotiva XSP-1 which will form the basis of the 2-channel signal chain. One which I will take advantage of once I get some monoblock amps; likely in 2014.

Music for tonight:
Feargal Sharkey - Feargal Sharkey (1985), man, haven't heard "A Good Heart" for more than a decade! Also revisited another 80's memory: The Jitters "Last of the Red Hot Fools" (1987) - Canadian, eh?

Addendum: After writing the above about 4K last evening, I ran across this link: 4K Blu-ray is dead tech walking. Yup, sounds about right! :-)

MUSINGS: Updates & The Value of Objective Measurements...

Life has been busy getting things done with the new home. Also, I went ahead and bought a new Paradigm SUB 1 to add to my home theater room along with a Signature C3 center channel - piano black of course :-)...  Should be an exciting fall/winter as I get things up and running!

In the midst of this, I'm going to try getting a few comparison measurements of the pre-amp characteristics of the new Emotiva XSP-1 vs. my old Denon 3802 AV receiver to see objectively what differences can be found. There does appear to be a significant audible difference plugging a DAC into the XSP-1 then into the Denon external input and using the Denon as an amp compared to just plugging the DAC straight into the Denon as a pre-amp.

A couple of quick updates:

1. It looks like JRiver has new beta versions of JRMC 19 (19.0.51) which supports the TEAC UD-501's native ASIO DSD128 mode. No problem with using "2xDSD in native format" upsampling of PCM to DSD now. Thanks to InflatableMouse for getting TEAC and Matt over at JRiver talking. With this "fix", there's no need for ASIOProxy any more but I suppose the technique could be useful for other DAC's.

2. I continue to update the list of suspected upsampled 44 & 48kHz PCM-to-SACD titles. Thanks for the entries from various friends and E-mails over the months. Again, I think it's useful to have a look at this list if you're a collector of SACD's. Useful to ponder just what is the benefit of DSD based on these examples as well...

The Value of Objective Measurements: A Case Study

Today, I want to discuss an interesting device which I heard back in early 2012 when a friend bought one (I think he might have even been on the wait list to be one of the first to get it)... The Wadia 121 Decoding Computer.

I remember listening to it and thinking "this isn't bad". Details seemed reasonable.  The remote feels good. I like the idea of good "lossless" volume control built into the DAC. I wasn't blown away by it though. Unfortunately, this was before I started writing this blog and spending time with measurements.

Over the months since then I remember keeping an eye on what others were saying about the device. I assume Wadia did a good job sending out "loaner" units to the various audio reviewers...  A Google search shows quite a number of subjective reviews of this device. At a price point of MSRP $1299, it's not a "top end" DAC based on price but that's still quite a chunk of change. Understandably, reviewers of "high end" gear did not suggest this was the best sounding DAC they've heard, but on the whole, it received very decent, positive remarks...  Let's have a look; I'll throw up a few summary quotes in no particular order based on the reviewers' conclusions trying not to take things too far out of context: [As usual, I present these quotes as "fair use" for the purpose of discussion, criticism, and research.]

The Computer Audiophile (August 16, 2012):
"The Wadia 121 Decoding Computer is more than competent and competes with products double, triple, and quadruple its size...  New computer audiophiles seeking their first entry into this wonderful next phase of high end audio can't go wrong by starting with the 121. They may never need another digital to analog converter."

Enjoy The Music.com (August 2012):
"The Wadia 121 Decoding Computer is the best affordable digital-to-analog converter that I've ever heard. No, I have not heard every affordable DAC on the planet – and there are new DACs in all shapes, sizes, and prices being released even as we speak. But given their track record, it is a safe bet that Wadia has not only put a lot of thought into the design of the Wadia 121, but this DAC won't be bested by any DAC for quite a few years to come..."

AudioStream (June 22, 2012):
"To my way of listening, the Wadia 121Decoding Computer jumps right onto my short list of recommended components. It strikes me as being at once refined yet not overly resolute, with a voice that sounds like music. Sweet music. I enjoyed every listening minute spent regardless of the recording..."
Wins the "Greatest Bits" award.

Sound And Vision (March 14, 2013):
"...Though the music sounded like high-res digital—not vinyl—my brain still involuntarily registered surprise at the lack of clicks and pops. I suppose it associates them with a relaxed listening experience.

"Home theater buffs tend not to think much about source components for music: We figure that as long as we own an Oppo, and maybe a turntable, we’re covered. That worked as long as music streaming was a low-res medium, merely a convenient plaything for background listening. But the advent of high-res downloads demands an upgrade if you want to get the best out of your investment in components and headphones. You just may need something exactly like the Wadia 121."
Awarded 5/5 stars in the "Performance" category.

Ultra High-End Review (June 20, 2012):
"... Reading reviews is helpful (I hope), but I think a proven track record of producing high quality components is perhaps even more important. Here Wadia, well known for producing some of the finest digital playback equipment available since the earliest days of the medium, has brought its considerable talents to bear in producing a DAC which is operationally bullet-proof at an unexpectedly modest price. This is not simply another DAC-in-the-box with off-the-shelf parts and a marketing slogan, but a component with highly sophisticated software realized in DSP which has been decades in the making, coupled with an analog section which, to my ears, is completely transparent. And with no separate preamplifier needed, your budget for speakers has just doubled. I can’t recommend it highly enough."

The Absolute Sound (Feb 28, 2013):
"I can state confidently that few, if any, potential purchasers will be disappointed by the 121’s sonics or ergonomics. I know that I could happily live with the Wadia 121—it’s that good."

So, these are words of subjective reviewers. As I noted, for the price this DAC cannot really be considered "reference" level at least from the perspective of folks who likely have heard DACs in the $5000+ range and have some expectation of what these expensive DACs sound like. There are of course comments about how this DAC doesn't quite reach the level of those über-DACs. Here's a nice quote from the Computer Audiophile: "What separates the 121 Decoding Computer from the rarefied air of great but greatly expensive DACs is reduced depth, air, and low level detail when reproducing the best recordings from labels such as Linn Records, Naim, and Reference Recordings." Fair enough.

So, eventually, in the July 2013 issue of Stereophile, we get their full review. Jon Iverson's subjective comments were clearly not as positive:
"After more than a month of use and listening, when I used the 121 strictly as a DAC, I found that, in most cases, its sound had a marginally burnished or rounded quality that could help tame a recording with an unruly top end, or slightly veil a great recording."

What was somewhat stunning however was what John Atkinson found on the test bench:

"Fig.4 shows the spectrum of the 121's output while it decoded dithered 16-bit data (cyan and magenta traces) and 24-bit data (blue and red traces) representing a 1kHz tone at –90dBFS. The increase in bit depth drops the noise floor by around 9dB, implying ultimate resolution between 17 and 18 bits. To generate this graph, I fed the data to the Wadia from the Audio Precision using an AES/EBU link. To my astonishment, when I repeated the analysis using a coaxial S/PDIF link to transmit the 24-bit data, I got 16-bit resolution. The blue and red traces in fig.5 repeat the spectrum with 24-bit data and an AES/EBU link; the cyan and magenta traces in this graph were taken with the 24-bit data transmitted with the coaxial S/PDIF link. I repeated the analysis using a TosLink connection from the Audio Precision, but with no difference in the result. To check that the Audio Precision was working properly, I then used a TosLink connection from my MacBook Pro. However, I got the same result: 24-bit data but 16-bit resolution. Finally, I used a USB connection from the laptop, and although I made sure that the connection was correctly set to transmit 24-bit integer data, the noise floor was around the 15-bit level (not shown)." (Emphasis mine.)

You can also see the noise level demonstrated in Figure 6 with the undithered -90.31dB graph. Not good. [I posted on this test back in August to show what it looks like with some of my DACs.]

Basically, what the objective results show is that we have here a fancy looking DAC with some really cool "talking points" - well respected manufacturer Wadia, "ClockLink" asynchronous USB, "DigiMaster" interpolation, 32-bit 1.4MHz upsampling. But at the end of the day, it's not capable of achieving >16-bit resolution with USB, TosLink, and coaxial inputs. Even with the AES/EBU balanced digital cable, it's "only" capable of 17-18 bits. Unless one were to just use AES/EBU, there appears to be no point feeding 24-bit high resolution audio into this DAC - all those 24-bit HDTracks/Qobuz downloads would be wasted (unless you feel >44kHz sampling is much more important). To make matters worse, it seems like the USB input cannot even achieve a full 16-bit resolution - arguably THE most important interface these days. Knowing this, how can any reviewer hand out awards or grade this device as 5/5 on performance? Even if you like the way this device "sounds", isn't it still a sign of failure that it could not profit from the higher bit depth? Of course, it appears the purely subjective reviews could not comment on this "inconvenient" piece of information.

Now, admittedly, there could have been something wrong with John Atkinson's measurements I suppose, but as of October 2013, I do not see any addendum to the review. I would imagine that a manufacturer would correct this situation ASAP!

I feel that this is a good case study (one of many IMO) into why objectivism has an important if not essential place in audiophile equipment reviews. Bias and placebo are well recognized in domains of research where human qualitative evaluation is involved. I would argue even more so when reviewing "high fidelity" gear where at a certain level of quality, differences are likely very small and effects of biases become even greater - "look and feel" (pretty metal box with lights and metal remote), manufacturer reputation (ooohhh... Wadia), price ($1299 must be a pretty decent DAC right?) all can (and likely do) end up in the final evaluation of sonic quality in the absence of objective information. In some forums / web sites, it almost seems that certain reviewers feel that they are immune to this phenomenon, or even worse, have developed so much faith in their "golden ears" that they feel there is no benefit to empirical evaluation.

Remember, thoughtfully designed audio devices are engineered. They were made based on electrical and (in instances like speakers or turntables) mechanical properties. Without examination of these properties to at least verify claims (eg. that a hi-res DAC is capable of >16-bit dynamic range being fed into it, or an amplifier is capable of the claimed watts with minimum distortion, etc...), I believe the reader cannot place strong value in the reviewer having fully appreciated the limitations/strengths of the device. I'm of course not opining that there be no subjective evaluation - fit and finish, ergonomics, ease of use, reliability, visual esthetics are all important. Likewise, sound quality needs to be checked subjectively. But there's no shame in admitting that in many ways, the human ear/brain is limited and measurement devices can easily enhance the quality of a review synergistically. There's no need to see this as black or white, subjectivist vs. objectivist.

I've said many times on the various forums how I still have a subscription to Stereophile. I look forward to reading the opinions, music reviews, and of course the gear reviews. After all that's said in the subjective portion, it's always good to study those numbers and graphs to make sure the device appears to be delivering all that was promised. I wish more magazines could do that... (Don't worry guys, I wasn't paid off by Stereophile, just wanted to give credit where credit is due.)

[BTW: Perhaps it goes without saying, I feel objective measurements are especially important with devices where the putative effects seem to be without clear scientific basis (eg. anyone know what the Synergistic "Tranquility Base" does yet?)]

Musical selection tonight: "Respect the classics, man!" -- Fillmore from Disney's Cars

     Jimi Hendrix - Band Of Gypsys

Until next time... Enjoy the tunes!

Changes... It Begins!

As I had mentioned a few months ago in one of the responses to a post, I had plans to "upgrade" my home sometime in 2014...

As fate would have it, a house opened up for sale recently fitting the family's needs and I decided to grab the opportunity. This is going to be a very busy autumn for me and the family with a move to the new place in November! Between now and then, I've still got 2 business trips among other duties.

The upshot to the move? I'll finally have a good sized home theater space for the transition to a dedicated sound room for both stereo and multichannel listening :-). With that in mind, I've sold off the Simaudio Moon i3.3 integrated amp I had been using for the last few years...  It's time to move on to separates and the first box in this new system is this baby:

Yup, the Emotiva XSP-1 pre-amp - I got it on sale recently at 10% off (~$820USD before taxes). In the next few months, I hope to get a couple of monoblock amps for the fronts (may consider the Emotiva XPA-1 Gen 2 coming out soon). In time I'll buy a processor for the fancy "new" surround formats like DTS-HD Master Audio. For now, I figure I can live with the 10-year old Denon AVR-3802 for decode duties with the ubiquitous Dolby Digital and standard DTS - obviously multichannel isn't a major priority for now.

Just a few comments about the XSP-1. It's a nice full sized component weighing a reasonable 28lbs. The rear panel layout is good and connectors are of good quality - gold plated and robust enough to feel that they're not going to fall apart any time soon. It has a phono preamp with impedance settings which I suspect I will never use (not interested in vinyl for now at least). Line level outputs to the amplifiers available as RCA and XLR's (fully balanced topology of course is a main selling point for this preamp compared to less expensive options). I'm looking at integrating something like the Paradigm Signature SUB 1 into the system so I believe I will be using the crossover setting real soon and keeping it at the 50Hz low end. It'll easily handle a single or dual powered subwoofers. There's also a "Home Theater Input" section to easily integrate this unit in bypass mode for surround functionality.

I see that a full set of measurements have already been published by Secrets of Home Theater and High Fidelity. For curiosity, I might try out a few RightMark tests to see what the difference is between this unit and the pre-amp output from the Denon AVR-3802 at various output levels...  Could be educational.

A look at the guts... A lot of opamps in there. Under the stylized 'E' metal shielding is the power supply and resistor network volume control.

In terms of subjective sound quality, so far I'm just running this in a compromised system. With the Simaudio gone, I'm connecting the XLR from the TEAC UD-501 to the XSP-1 and routing the RCA output to the Denon's "external in" and using the receiver's amplifiers to drive the Paradigm Signature S8's... All I can say is that it does sound better than TEAC RCA to the CD input of the Denon. I wonder if the Denon is doing any internal ADC/DAC step even in the "Direct" setting which is supposed to defeat any DSP happening. For example, listening to Yello's 2009 album Touch Yello, the spatial ambiance and sense of "surround" was more prominent with the XSP-1 than directly into the Denon. Those Q-Sound albums like Madonna's Immaculate Collection, Def Leppard's Yeah!, and Sting's The Soul Cages also sounded fuller. Again, I'll see about obtaining some measurements and compare the quality of the Denon output with this new stereo preamp.

Nice metal remote. No problem getting programming for the Logitech Harmony I normally use.

If there is one criticism I have about this unit, it would be the headphone amp and output. As you can see from the first picture, the headphone jack is the small 3.5mm variety. It's fine for most of my headphones but for the higher end units like my Sennheiser HD800, I'd prefer the full 6.5mm (1/4") plug rather than having to use a converter.

The preamp will mute the line level output when it detects headphones in place so that's appropriate. The other issue is that the headphone output is relatively weak. The most power-hungry headphones I have is the AKG Q701. At full volume, it's loud enough for most rock/pop recordings. However, classical recordings with higher dynamic range and produced at softer average levels would need a more powerful headphone amp.

As always... Enjoy the music :-).

BTW: Can anyone recommend some good audio equipment stands? I'm planning to hang the flatscreen TV on the wall so don't need a TV stand. Something like the stackable Lovan Sovereigns look like a good idea since I will have enough room to put two low stacks side-by-side in front of the TV on the hardwood floor. If you know of other models/brands, I'm "all ears"!

MEASUREMENTS: PCM to DSD Upsampling Effects (JRiver MC19 Beta).

We're continuing to see a push into the DSD domain with renewed talk of music release as digital downloads requiring the purchase of a DSD DAC to natively play (eg. recent Acoustic Sounds DSD releases). For now, I have already voiced some concerns about DSD including practical issues like the gross limitations of the file format itself. I demonstrated the noise characteristics for both DSD64 and DSD128 in my TEAC measurements. Furthermore, I have shown that there already exists many SACD's appearing essentially to be upsampled PCM from standard sampling rates of 44/48 kHz (remember, it's almost a given that any music we listen to created in the last 20 years has at some point been through a PCM stage except specified pure analogue recordings or those specifically recorded in DSD with minimal processing).

Some writers have voiced that even the process of upsampling PCM to DSD will imbue the music with some of DSD's beneficial properties, is this true? If so, what happens?

Well, thanks to ongoing advancement in the computer audio world, we can now easily have a way to listen to our PCM music as a converted DSD stream... Enter JRiver Media Center 19 and it's ability to stream PCM --> DSD64/128 in realtime to a compatible DAC. [Note that this should also be possible using ASIOProxy from foobar - not tried personally.] This will allow an easy way for everyone to listen for themselves what happens to the sound either as the original PCM or transcoded to DSD with the assurance that we're comparing "apples-to-apples" with the same mastering.

First, as has been my custom, let's start with some objective measurements to see what the DSD encoding does to test signals.

I. Objective Measurements

General Setup:
AMD A10-5800K HTPC Win8 x64 running JRiver 19.0.37 (ASIOProxy workaround for DSD128) -> shielded USB -> TEAC UD-501 -> shielded 6' RCA -> E-MU 0404USB -> shielded USB -> Win8 laptop

TEAC DAC settings:
     - PCM: "SHARP" BB PCM1795 filter, no upsampling (default)
     - DSD: FIR3 analogue filter (closest volume match to PCM output)

JRiver Media Center 19.0.37 setting:
     - ASIO buffer set to "minimum hardware size" since someone suggested it sounded better :-) - no stuttering encountered playing music.

First, let's have a look at the 1kHz SQUARE WAVE off the digital oscilloscope (24/44 source):

PCM:

DSD64 realtime conversion:

DSD128 realtime conversion:

As you can see, volume is about the same with the DSD FIR3 filter on the TEAC vs. PCM SHARP; both output ~2.85V peak with the square wave. What is also very obvious is how clean the PCM is vs. DSD. Notice the extra high frequency noise for both the DSD64 and DSD128 traces, with the DSD128 clearly less noisy. No surprise, right? If you've looked at the objective results from DSD here and elsewhere, this is pretty "normal" for DSD.

IMPULSE RESPONSE (16/44 PCM impulse):
PCM SHARP filter:

DSD64 realtime upsampling:

DSD128 realtime upsampling:

Noise is again very evident in this "zoomed in" impulse response measured at 24/192 especially from the DSD64 process. Although impulse response graphs can be excellent with MHz sampling rate (this is often a "talking point" in the DSD/Sony ad literature over the years), when resampling PCM to DSD, we're still hampered by the PCM signal's original sampling rate (eg. 44kHz). Evidently JRiver uses a typical linear phase reconstruction filter; hence the symmetrical pre- and post-ringing.

DUNN J-TEST:
PCM:

16-bit

24-bit

DSD64 realtime upsampling:

16-bit

24-bit

DSD128 realtime upsampling:

16-bit

24-bit

No meaningful differences between PCM and the DSD realtime conversion. This also means no evidence of worsened jitter with all that extra processing converting PCM to DSD in the computer at least based on the spectral output of this test (typically, this computer's AMD CPU utilization went from <5% with PCM to ~15% for DSD upsampling). DSD64 is obviously of enough resolution to accurately demonstrate the jitter modulation signal in the LSB for the 16-bit test.

RightMark:

Calculations done in the AUDIBLE SPECTRUM (20-20kHz).

Frequency Response

Noise

THD

These graphs of upsampled 24/192 test tones echo the results in the TEAC DSD Measurements back in May. I used KORG Audiogate to convert PCM to DSD back in May and it looks like the mathematical process in both JRiver and Audiogate are of similar precision. Within the audible spectrum, the PCM and DSD measurements are all very similar. A good indication of high precision in the conversion process. What is again evident is the noise once we get above 20kHz especially with DSD64.

II. Subjective Experience

As per the premise of this blog being "more objective", I'm not going to write pages on that which is experienced for oneself. However, I'll put down a few thoughts for consideration...

Listening gear:
     - Headphones: Sennheiser HD800 off TEAC DAC
     - Speaker system: TEAC UD-501 --> Simaudio Moon i3.3 --> Paradigm Signature S8 v3 (standard OFC cables)

The DSD conversion process through this TEAC DAC does change the electrical output as seen by the objective measurements above. This alone means that it's real compared to the identical measurements found with different bitperfect software and digital cables previously reported.

There does seem to be a change in the perceived detail of the sound subjectively through the gear I listed... Note that I'm taking the liberty here to not subject myself to a blind test so I fully admit that I could be wrong on this :-). Furthermore the fact that since it's not an instantaneous 'flip', echoic memory is prone to be unreliable. With these caveats, my current feeling is that both DSD64 and DSD128 conversion adds a potentially euphonic characteristic to the sound. No, IMO, it's not a dramatic difference when listening volume is controlled. [For those using the TEAC DAC, remember that the default FIR2 filter for DSD is louder than PCM by ~2.5dB - this could of course be misconstrued as sounding "better" for DSD.]

What do I hear? As I mentioned in my previous post on getting DSD128 upsampling working on the TEAC, I think the sound is less "etched". There's a pleasant subtle added smoothness to the transients. I think many may describe this as being less fatiguing, maybe less of the "digital glare". I couldn't specifically put a preference on DSD64 vs. DSD128 but knowing the ultrasonic effects, it wouldn't take much to convince me that DSD128 is better since the ultrasonic noise is further away from the audible spectrum. However, if you believe that the noise itself creates euphonia, it's also conceivable that DSD128 would sound closer to PCM than DSD64. Maybe.

I listened to a few standard 16/44 albums in DSD128 like a first pressing Michael Jackson Thriller, the well recorded Al Di Meola Winter Nights, and Suzanne Vega's Solitude Standing. They all sounded great. Like I said, marginally smoother than PCM. I think poorly recorded harsh albums may benefit even more - for example Alan Silvestri's The Avengers score is mastered in "modern" overcompressed fashion with DR9 average dynamic range (not good for an instrumental soundtrack IMO). DSD128 upsampling seemed to make it more listenable for longer duration.

Vinyl rips (24/96) of Tracy Chapman's Fast Car and Whitney Houston's One Moment In Time sounded very nice as well... "Extra" analogue from digital from vinyl :-). Again, the inability to instantaneously switch between PCM-to-DSD makes it hard to A-B compare reliably.

Unfortunately I did not take a screenshot of the phase measurements, but it looked good. Listening to phase-effect tracks such as those encoded in Q-Sound like Def Leppard's Rock On (David Essex remake off Yeah!), and Roger Waters' Too Much Rope (off Amused To Death) nicely created the impression of spatial surround and depth. Whether that sense of depth is any better with the DSD upsampling is of course debatable.

III. Conclusion

1. PCM to DSD upconversion is a DSP process. The signal output is measurably different.

2. Noise shaping pushes the DSD quantization noise into the ultrasonic frequencies as expected. In DSD64 it rises above the noise floor almost right at 20kHz, and in DSD128 it starts around 40kHz. (I vote for pushing it up to 40kHz as less likely to cause distortion through the amp & speakers.)

3. Pre- and post-ringing is similar to standard PCM with upsampling using MC19's algorithm so this would not explain any audible differences.

4. The algorithm used in JRiver MC19 does a good job with maintaining classic measurement parameters like frequency response, dynamic range, and distortion from 20-20kHz  - basically this means the math is as expected and fits the DSD output profile. Results are similar to the KORG AudioGate software converting PCM-to-DSD.

I can't help but wonder if what's happening here is like tube amps and analogue playback (eg. vinyl). Objectively the DSD conversion adds distortion but the anomalies are not perceived as objectionable and in some material, the added noise and imprecision actually makes it sound less "sterile", "clinical", more "real" (conversely being in an anechoic chamber is disturbingly unreal due to the profound silence). It would make sense to me that some people could prefer DSD64 over DSD128 upconversion since DSD64 will give you more of that distortion. Even though the noise is ultrasonic in nature as measured off the DAC, nonlinearities in the playback system like your headphones and speakers (perhaps certain amps as well) could create audible intermodulation. Maybe for certain music, this could be especially beneficial.

Out of curiosity... For anyone out there with the EMM Labs DAC2X which upsamples to DSD128, it'd be great to have a look at what the measurements are from that unit! With all the positive press about how this DAC sounds (ahem... $15.5K), I have yet to see any measurements... I wonder what a 16/44 impulse response looks like for example to see if it bears similarity to what JRiver is doing. How about the ultrasonic noise with DSD64 & analogue filter strength? Does the EMM upsampling process for PCM result in similar frequency response pattern?

In any case, give this PCM-to-DSD process a try at some point when you can. If nothing else, at least to say you've experienced it... See if you can perceive a difference and/or judge if it's beneficial for yourself.

Tonight's music: Valery Gergiev & LSO's Mahler Symphony No. 9 (2011). Nice recent classical recording available in SACD format as well.

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You might notice that I turned on AdSense on the blog.

As I have said in the past, my intention for this blog has never been about making money. I have no formal relationship with any company so have no sales incentive and am not interested in making this some kind "publication" other than what it has been - a blog about my own journey in audiophilia with a bent towards finding answers using empirical/objective means. That remains my main interest.

Nonetheless, it's trivial to "flip" the AdSense switch. I would have no idea what Google tries to market to you, and trust that the layout won't be distracting (I've switched off some questionable types of ads like for dating sites or of a sexual nature). If it gets me a few bucks for my digital downloads for what I do as a hobby anyway, I'll be happy with that!

Best regards...

HOWTO: Getting JRiver MC19 PCM to 2xDSD (DSD128) upsampling working on TEAC UD-501...

A quick post here for those trying to get beta JRiver MC19's 2xDSD (DSD128) upsampling working on the TEAC UD-501. [Currently I'm using beta MC19.0.37.]

See the thread here where the discussion was started - thanks for putting attention on this InflatableMouse. Apparent there are some buffer issues with the TEAC driver and native ASIO, and at this point MC19 isn't supporting a 2xDSD upsampling with DoP option. Here's a workaround:

1. Download and install ASIOProxyInstall-0.6.5 from the SourceForge link here.
2. Go into MC19 and set audio device as "foo_dsd_asio [ASIO]", Bitstreaming as "Yes (DSD over PCM (DOP))". Should look like this:

3. Now lets set up ASIOProxy itself. Go into that "Device settings..." tab. Look at the "Tools" section and click "Open Driver Control Panel...". You'll see this pop up:

Make the settings as above especially with Fs as DSD128.

4. Finally, go into "DSD & output format..." in MC19 and set output format to "2xDSD in native format":

There you go.

Should now be listening to all PCM music upsampled to DSD128 on the TEAC. Native DSD files will be bitstreamed in their respective DSD64 or DSD128 forms direct to the DAC without MC19 processing like volume control.

Using an AMD A10-5800K processor, I'm seeing CPU use peaking at ~20% and usually 10-15%  even with upsampling 24/192 music. Not bad!

Hopefully TEAC and JRiver can come up with a solution for native ASIO streaming or support of DSD128 upsampling in DoP in the future...

BTW: I just got back from holidays a little jet lagged so haven't played with this much yet. However, on my system, upsampling to DSD64/128 certainly sounds different than PCM and I can certainly see the appeal - there seems to be more weight to the bass and the sound isn't as "etched".  There is a bit of level difference between DSD & PCM playback so I will need to listen more back and forth to see which setting I prefer.