Music in the Round #75 Page 2

Auro Technologies sent me a small stack of Blu-ray discs, while Dolby sent along only a single demo disc—so Atmos was at a disadvantage: The only music track on the Atmos sampler was "Bailando," a music video by Enrique Iglesias. The video cut repeatedly among multiple venues, indoors and outdoors, but the ambience presented never changed. Discounting the audio/video disassociation and my admitted lack of interest in the music, the sound was clean, direct, and of generous if inappropriate ambience. It didn't make much of a case for Atmos.

The Auro-3D music was more wide ranging, from the spacey-synth of Lichtmond's 3: Days of Eternity (Blu-ray, Lichtmond LM022) and the indie-rock synths of Mando Diao's Ælita (Blu-ray, Black Hole 1623) to three Blu-ray discs from 2L Records: Remote Galaxy, music by Flint Beppe with Vladimir Ashkenazy conducting a very large Philharmonia Orchestra (2L 100); Spes, a collection of sacred choral music sung by the European a cappella group Cantus (2L 110); and Andre Arnesen's Magnificat for chorus and orchestra, with Anita Brevik conducting the Nidarosdomens Jentekor and the Trondheim Soloists (2L 106). My take on all of these, including the Iglesias/Atmos, was that the addition of the height dimension opened up the sound of the recording venue without corrupting the imaging: nice, but not compelling. Still, I think that if we had a significant body of music in Atmos and/or Auro-3D, we would quickly adapt to this new spaciousness, and miss it when it wasn't there.

Almost the same can be said about what each of these technologies did with regular stereo and multichannel recordings. The effects were similar but more subtle. I preferred Auro-3D because it had less of an effect on tonal balance than did Dolby Surround, upmixing which also made the center channel more prominent. On the other hand, both Atmos and Auro-3D were impressive with ambience-only recordings in which they set up microphones in a rainforest or a busy city intersection, to immerse the listener in those aural scenes. Here, the expanded depictions were much more convincing than through just 5.1 channels. Similarly, the few movie clips worked very well. Maybe there's a future for these formats in home theater, but it will be a hard sell for music lovers.

The Marantz AV8802A does everything its predecessor did, and more. It adds support for Atmos and Auro-3D. Its Audyssey calibration is easily competitive and now supports the multiple-speaker configurations of the new immersive formats. Finally, the decidedly improved analog outputs benefit all audio functions, including analog multichannel pass-through. If your concern is primarily for music playback, can you do better spending $1000 or so for a separate multichannel preamp? No way. It's easy to recommend the AV8802A, despite the bump in cost: It offers cutting-edge features and outstanding sound.

UpTone Audio USB Regen
In the last installment of "Music in the Round," I introduced the miniDSP U-DAC8 ($299), an eight-channel USB DAC at 1/10 the price of its nearest competitor—great news for anyone wanting to start playing multichannel files. Enhancing the sound with Dirac Live toned down the glint in the treble but didn't help the swimming instability in the soundstage. It was as if the balance was shifting under my feet (and before my ears)—the effect was most pronounced in the surround channels. Because it's obviously built to a price, the U-DAC8 would be a likely candidate for some of the many devices offered to improve USB transmission or power supply; of the several such things I looked into, the first to arrive was UpTone Audio's USB Regen ($175, footnote 4).

The Regen is basically a USB repeater that uses the digital datastream from your source to generate an entirely new USB signal to send to your DAC. Inside it is a USB hub chip supported by low-noise voltage regulators and a low-jitter clock. The Regen has its own power supply, which UpTone says is "the best spec'ed and sounding 22 watt/7.5V/2.93A (overkill) tabletop (93 x 54 x 36mm) world-voltage-compatible SMPS we could find." The 5V from this supply feeds pin 1 of the output USB and replaces the 5V bus from the incoming USB. The Regen's USB plug is meant to be inserted into the DAC's input via a short (ca 3"), stiff, male-male adapter plug, to eliminate any variables due to a longer input USB cable. If you can't fit the Regen into your system that way, a 6" cable is also provided. UpTone says that the Regen should be transparent to your source. I inserted it between my Mac mini (running Windows 7 via Apple's Boot Camp) and the U-DAC8; setup required only a computer reboot and reselection of the U-DAC8 as the output.

It was as if the Regen weren't there—until I began listening closely. The fundamental quality of the sound was better. All hints of the abiding brightness were eliminated and, as a result, the frequency balance was smooth and unaccented. The bass, with or without Dirac Live, was firmer. However, the biggest change was in image balance and stability. My sensitivity to such flaws increases with volume level, and I realized that I'd tended to play music at lower levels with the U-DAC8 to avoid being distracted by the surround-channel signals, whether discrete or just ambient. For example, the 24-bit/96kHz, 5.1-channel FLAC file of Willie Nelson's Night and Day (DVD-A, Surrounded-By SBE-1001-9) has instruments discretely positioned at and between the speakers. Without the Regen, those instruments whose images appeared between speakers seemed more vaguely positioned; with the Regen, they were rock stable. Through the Regen, I listened to another favorite: Manfred Honeck and the Pittsburgh Symphony's recording of Dvorák's Symphony 8 (SACD/CD, Reference fresh! FR-710SACD). Now I could turn up the volume to live-concert level without suffering any queasiness due to uncertain ambience.

If it could work the same magic with higher-priced DACs such as my exaSound e28, the UpTone USB Regen, at $175, would qualify as a logical addition. But I don't yet know, because I lent the e28 to JA. A $175 accessory for a $299 DAC might seem inappropriate, but I think it's a bargain. Think of it as creating, for less than $500, an eight-channel DAC whose sound is comparable to that of two-channel DACs for the same price or more.

My DIY battery power supply
In an e-conversation with exaSound's George Klissarov about galvanic isolation in his company's D/A converters, he told me that he used measurements done with battery power, so that the lower noise floor would reveal any influence of noise in the USB line. Despite Klissarov's comfort with the performance of the 12V/1670mA power supply that exaSound provides, the owner's manual says that a better power supply "may allow you to squeeze the last bit of performance from the e28 DAC." A number of external power supplies might work (one is on the way to me), but Klissarov's intimation that a battery would be the ideal power source hit my DIY button.

I don't do it myself much anymore, but I've been involved in DIY audio for most of my life and, like most DIYers, I often believe I can do things better and cheaper. Running a 12V battery is easy, but it has to be recharged; my solution is a 12V DC backup power supply that, when unplugged from the AC, runs the output on battery. I chose a Belkin Residential Gateway (RG) Battery Backup, model BU3DC001-12V Rev B ($129.99 list price). Made to support an AT&T network service device for voice telephone service, it has a 12V, 7.2Ah sealed lead-acid battery. You can find them on eBay for under $50; I bought mine at a flea market.

For basic use, all you need to do is change the Belkin's output connector: It comes with a standard barrel connector (5.5mm OD, 2.1mm ID), while the exaSound requires a 5.5/2.5 (aka N) connector. Snip the wire, solder on the new connector—make sure the + lead goes to the inner conductor—and you're done. Oh, not quite: Make sure you flip the Mute switch on the Belkin to On, or you'll be subjected to piercing tones whenever you turn the AC On (charge) or Off (battery power) (footnote 5).

What did I gain? Mostly, satisfaction. When I changed from the exaSound power supply to the Belkin set to AC, I could hear no difference in noise level or sound quality. When I switched the Belkin to battery operation, things weren't so certain. Background noise in the absence of a signal was already so low that, in a sighted test, the quiet click of the Belkin's relay obscured my ability to choose. However, with battery power, the music seemed ever so slightly smoother and cleaner, with better distinction between music and ambience. I don't know if I could hear that difference with statistically significant consistency in a blind test, but I feel righteous about feeding my DAC the most wholesome juice diet possible.

Footnote 4: UpTone Audio LLC, Mariposa, CA 95338. Tel: (209) 966-4377. Web:

Footnote 5: I also added two nonessential gadgets: a three-digit LED voltmeter wired in parallel to the Belkin's output, to ensure that the battery charge was within usable range (see; and a remote-controlled AC switch (the Belkin has none). Inserting and removing the AC cord works, but is a bother.


ssimon's picture

I've got a question I'm hoping you can answer. I've got a Marantz 7702 pre/pro. I'm happy with it. I also have an Oppo 103. I'm happy with it. But I have a feeling that both are processing the video signal, which is something I probably should not be happy with. If that's the case, which component should do the processing? And how do I block the other component from processing?
I apologize for the bottomless ignorance that generated this question...
Best S

Kal Rubinson's picture

Just saw this post and have to admit equal ignorance of video issues.