Music Hall dac25.3 DAC and Headphone Amplifier Review

September 15, 2011

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A year or so ago, Sam Tellig reviewed the Music Hall dac25.2, the predecessor to the dac25.3 I have in house for review. What did Sam use as a source? Internet radio, and in particular KCSM, a San Francisco jazz station. KCSM broadcasts at two bit-rates: 32kbps for dial-up and 64kbps for broadband. I feel sorry for the two or three listeners still using dial-up. At 32kbps, I wonder if they can even tell it’s jazz? I feel only slightly better for the rest of KCSM’s listeners. I don’t have to tell you that at 64kbps the sound quality is, shall we say, compromised. That’s half the resolution of iTunes’ lowest quality download. Sam was auditioning the DAC in his office through some old Advent active speakers plugged into the headphone jack of the dac25.2. His conclusion: “I thought the sound of Internet radio was splendid.”

I bet Roy Hall about fainted when he read Sam’s review. There wasn’t a snowball’s chance in hell that his DAC would be able to show its stuff under the circumstances. Notwithstanding Sam’s pronouncement, not even the $11,000 dCS Debussy, with its asynchronous USB input and software-based Ring DAC, can make 64kbps streaming audio sound like anything other than AM radio. Roy Hall, industry stalwart and friend to entry-level audiophiles everywhere, deserves better. I will be auditioning his dac25.3 using 44.1/16, 96/24 and 192/24 lossless files. The corresponding bit rates are 1411kbps, 4608kbps, and 9216kbps. The DAC’s output will be routed through the analog input of Benchmark’s DAC1 HDR preamplifier to a Meridian 557 power amplifier and Living Sounds Audio’s noteworthy LSA.5 loudspeakers, which I reviewed here.

The Music Hall dac25.3 is a fairly substantial piece of gear compared to some of its competition. Though only 8.5” wide, its depth is 13.5”, significantly more than appears from its product photo. You will need every bit of half a shelf to accommodate it. There is a reason of course. It has an oversized power supply utilizing a hefty high-current r-core transformer; and it needs room for the tube analog stage. On the right rear of the top plate, there are ventilation holes over the single Electro-Harmonix 6922. They must be there out of an abundance of caution. Even after having left it on overnight, it was barely warm to the touch. Weighing in at around 8lbs, you have quite a package.

The front panel is neatly arranged. On the far left is a push-button power switch. Adjacent to it is an input selector button for the coax, optical, USB and XLR (AES/EBU) digital inputs. Moving to the right, there is a selector button which allows you to playback the input at its native sample rate, or upsampled to 96kHz or 192kHz. I like being given a choice. Both the input and upsampling options have blue LEDs to confirm your choice. Mercifully, they are not blindingly bright. Rounding out the right side are a standard ¼” stereo headphone jack, and the headphone volume control. It is both knurled and detented, giving it not only a great feel but repeatable settings as well.

Around back are the digital input jacks, and both balanced and unbalanced analog outputs. The unbalanced output is derived from the tube analog stage and has 0.04% THD+N. The balanced outputs are derived from a solid state stage and have much lower distortion – 0.0015% THD+N. Pick your poison. The analog output is fixed; the volume control only affects the headphone output. There is also an IEC inlet, and a 115v/230v voltage selector switch thoughtfully protected from inadvertent change by a plastic barrier.

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If I had a hand in the design, I would add a switch on the back to choose between fixed and variable output. That would eliminate the need for a separate preamplifier in your system, making the dac25.3 even more attractive. In the absence of such a switch, you could follow Sam Tellig’s lead and simply get a ¼” stereo plug to two RCA jacks adapter, plug it in the headphone jack, and run interconnects to an amplifier or pair of active speakers. It’s a bit of a kludge, but it works fine. Perhaps we will see variable output in the dac25.4.

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The dac25.3 does not come with a USB cable, which is a shame, since there you are, all excited to get the thing hooked up, and a little of the shine is taken off by having to stop and scrounge around for one. If you are like me, you probably have a half a dozen non-audiophile approved USB cables squirreled away in a box or a drawer somewhere. I’m reasonably well organized so it only took me a few minutes to track one down. In a pinch, just take the one off your printer. Trust me: you are going to be listening to a lot of music before you get back to printing anything.

Cable in hand, I plugged one end into the dac25.3 and the other into USB port on the rear of my IBM ThinkPad running Windows XP. A little dialog box pops up near the system tray assuring you that it has recognized the Music Hall dac25, and it begins installing device drivers for – are you ready – a USB Composite Device, a USB Human Interface Device, a USB Audio Device, and a USB HID-Compliant Device, none of which are Microsoft approved. Just click on the “Continue Anyway” button and in no time at all you are set to go. Don’t worry; this isn’t a Music Hall issue; it’s a Windows issue. The same thing happens when you plug in nearly any USB device other than a Microsoft mouse or Microsoft keyboard. About now Mac users are smirking about what Windows users have to go through to connect something up.

The USB interface is adaptive; however, the incoming signal is immediately re-clocked and de-jittered using a Philips 74HC574 octal D-type flip-flop logic chip and TI SRC4192 asynchronous sample rate converter. This is the same approach Benchmark Media uses in its USB DACs. As we learned in my interview with Halide Design, adaptive interfaces can outperform asynchronous ones; each is only as good as its design and implementation, so don’t reject the dac25.3 out of hand because it does not employ an asynchronous USB interface. The proof is in the listening.

The dac25.3 accepts 44.1kHz, 48 kHz, 88.2 kHz and 96 kHz sample rates at up to 24 bits on its USB input; the coaxial S/PDIF, Toslink and AES/EBU inputs add 176.4/24 and 192/24 to the mix. So unless you are a professional recording engineer working with DXD and/or DSD audio files, you have all of the bases covered. If you can download it, you can play it.

I first auditioned the dac25.3 with headphones. If you are just starting out in life, you are probably living is a small apartment with thin walls. No space for a hi-fi system with floor-standing speakers and neighbors that don’t share your musical tastes? One of the quickest and least expensive ways into the high-end is with a quality set of headphones. Add a USB DAC/ headphone amp combination like the dac25.3, plug in your laptop and you are in business. Great sound for under $1000. You’ll never listen to music through your iPod and earbuds in the same light again. I find over-the-ear headphones uncomfortable for long listening sessions and have settled on Etymotic ER-4S balanced armature in-ear earphones with custom fitted ear-molds, which weigh less than an ounce. They are 100 ohm earphones and thus require a headphone amplifier. There is also a ER-4P model specified at 27 ohms which can be driven directly from an iPod. There are lots of other great headphones out there at all prices. The affordable Grados come immediately to mind.

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I expected the headphone output to sound lush, but it was surprising neutral. Turns out, the gain stage for the headphone output is solid state, and the tube circuit is used only as a buffer. The same is true for the balanced analog outputs. That’s fine with me. I heard nothing out of place and the headphone jack provided plenty of gain for even high impedance headphones which soak up power. The sound was full-bodied without being round, and the high frequency was extended without being harsh. Long listening sessions were not a problem. I then moved on to listening to the dac25.3 using its unbalanced analog outputs. In this configuration, the tube analog stage provides the gain.

I don’t listen to much rock and roll, either when listening for pleasure or when auditioning components. I don’t think amplified music tells you much about a component’s ability to accurately reproduce a recording. It can tell you whether an amplifier has enough power to drive your speakers to high levels without distortion, particularly in the low frequencies, and whether your speakers have the ability to play loud without breakup, but it does not provide the ability to judge nuance, which is how high-end components distinguish themselves one from another.

With that in mind, first up was Cecilia Bartoli and Bryn Terfel Duets, a recording of duets from Mozart, Rossini and Donizetti operas, to check out both male and female vocals. Bryn Terfel, a Welsh bass-baritone, has an amazingly rich and resonant voice. Cecilia Bartoli is a coloratura mezzo-soprano, and is capable of astonishing vocal fireworks, a hallmark of the bel canto repertoire. Together, they cover the range of human voice – and in a delightful manner. I played the 44.1/16 audio files back on my music serving using the USB input.

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Again I was surprised by the essentially neutral character of the DAC. It just goes to show you that the stereotype of tubes sounding warm is just that – a stereotype. If you are searching for that “tube sound,” it is important that you actually audition the tube component you are considering purchasing to determine if its sound is going to meet you expectations. The dac25.3 definitely does not fit the mold. If anything, I thought the presentation was light and nimble. I was particularly impressed with its dynamics. The transition from pianissimo to forte was seamless and graceful. I tried upsampling the Redbook CD stream to 96kHz and 192kHz and could detect no difference. Perhaps it would be evident with different music and/or a more resolving system. Or perhaps not.

I next turned to Viola Bouquet, a collection of works for viola and piano, featuring Nobuko Imai on the viola. The viola is tuned one fifth below the violin, giving it a richer, more sonorous sound. It is an excellent test for the lower midrange. The dac25.3 did not disappoint. The viola tone was as it should be, harmonics were clean, and the accompanying piano was well reproduced. Imaging was excellent. I heard no harshness or glare. I compared the dac25.3 to my Meridian G68ADV, and while the later may have rendered a somewhat more fleshed out presentation, the difference was small, at least when using the LSA.5 monitor speakers.

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Finally, I confirmed that the dac25.3 will in fact handle 96/24 files through its USB input, and 176.4/24 and 192/24 files through its coaxial digital input by playing Gottschalk’s Suis Moi! Caprice from Reference Recordings (176.4/24) and The Eagles Hotel California from HDTracks (both 96/24 and 192/24) . There were no hiccups. To paraphrase Sam Tellig, I thought the sound of high resolution digital files was splendid!

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Conclusion

It is hard to find fault with the Music Hall dac25.3. It is a solid performer. It provides all the digital inputs you could ask for, its DAC can handle all sampling rates and bit-depths, and it has an excellent headphone amplifier. In a pinch, it can be used as a preamplifier. In short, it serves as an excellent component around which to build a credible entry-level system. At $599, it is a bargain, and leaves plenty of room in your budget for a power amplifier and a pair of top-notch loudspeakers. My only caveat is that if you are looking for “tube sound,” you may want to consider alternatives. Recommended.

- Frank Berryman

Contact Information

Music Hall Audio
108 Station Road
Great Neck, NY 11023
(516) 487-3663
http://www.musichallaudio.com
[email protected]

Associated Equipment

Analog Source: VPI Scout; Dynavector 20X2; Musical Surroundings Phonomena II
Digital Source: Windows 7 music server with ESI Juli@ soundcard; Halide Design Bridge
Preamplifier: Meridian G68ADV; Benchmark DAC1 HDR
Power Amplifier: Meridian 557
Loudspeakers: Meridian DSP5500; Living Sounds Audio LSA.5
Cables: Digital: Meridian; Analog and Speaker: Audience Conductor “e”; Power: Volex/Marinco
Headphones: Etymotic ER-4S
Accessories: GIK acoustic treatments, Target HR speaker stands, dedicated 20 amp circuit