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- Written by Garrett Hongo Garrett Hongo
- Category: Full-Length Equipment Reviews Full-Length Equipment Reviews
- Created: 15 February 2014 15 February 2014
Just so you know, T+A stands for “theory and application” -- there is nothing even vaguely Vegas about it. This German audio company has been producing loudspeakers since 1978 and a full line of electronics since 1988. Recently, they released the DAC 8 ($3250 USD), a ‘tweener-sized digital-to-analog convertor that can also drive an amplifier directly via its own analog volume control. It also doubles as a headphone amp. I hadn’t known much about the company when editor Jeff Fritz asked if I’d be interested in reviewing the DAC 8, but I’d become very curious about desktop DACs. I’d reviewed Hegel Music Systems’ splendid HD25 ($2500) in August, and had acquired an Eximus DP1 ($3200), both capable of wondrous sound at affordable prices below those of shelf-sized DACs made by the likes of Berkeley, Calyx, and Resonessence. I quickly agreed.
The T+A DAC 8 arrived late last spring. Although I immediately took to it, I wasn’t able to give it the kind of concentrated listening it deserved until early in the fall. Once I did, it impressed not only for its sound, but for its sophisticated features and many controls.
A wealth of innovations, features, and quality parts is thoughtfully integrated into the DAC 8. Its imposing front panel is rich in features, including a high-quality analog volume control. There are galvanic isolation of the digital and analog stages, separate power supplies for the digital and analog sections, and superior components for all critical functions. The DAC 8’s USB input supports two settings: USB 1 for resolutions up to 24-bit/96kHz and USB 2 for resolutions up to 24/192. USB 1 uses synchronous (adaptive) transmission. For the USB 2 option, with a special downloadable driver, asynchronous transmission is used.
A serious engineering firm, T+A has found its own way of dealing with the vexing problem of jitter -- i.e., fluctuations in the rate of data transmission -- in the handoff from computer to DAC. The DAC 8 removes coarse jitter before it reaches its microprocessor via a special circuit that reclocks the entire datastream. Two separate quartz oscillators ensure that perfect converter clocks are available for all sampling frequencies from 44.1kHz up. And, at the penultimate digital stage, the DAC 8 employs a second jitterbug that can head off the operation of the quartz oscillators if any jitter remains.
The DAC 8’s converters are an array of four 32-bit Burr-Brown devices configured in a double symmetrical circuit. T+A claims that this arrangement results in noticeably improved linearity and dynamics, less distortion, and greater clarity of tiny musical details, even at low volume levels. As already noted, these converters are galvanically isolated from the DAC 8’s analog section to prevent interference from the computer and other sources creeping into the analog signal.
A 56-bit signal processor does the oversampling. T+A has developed proprietary algorithms to ensure what one of their online brochures calls “perfect timing in the audio signal.” T+A’s algorithms, based on Bezier polynomials, are represented by two filtering options on the DAC 8’s front panel: Bezier interpolation and Bezier/IIR combination. There are also a standard FIR filter, a short FIR filter, and an option for inverting absolute phase. T+A engineer Lothar Wieman insists that these algorithms aren’t mere sound shapers in the sense of tone controls, but complex means for preserving the exact shape of each musical signal. This prevents digital artifacts like pre- and post-ringing being added to the signal.
Finally, the DAC 8 has a switchable analog function that can either restrict the bandwidth to 60kHz or widen it to 120kHz, depending on whether the DAC 8 is used with a power amplifier capable of broadband output or not. The ultrawide 120kHz setting is for improved frequency response and phase linearity. This purportedly results in a more open sound, clearer and more stable imaging, and livelier dynamics.
Many compact DACs include op-amps because of their convenience and small size. However, T+A believes that op-amps compromise the sound and doesn’t use them in the DAC 8. This eliminates the need to use negative feedback, which T+A believes can degrade linearity.
Description and setup
The DAC 8 is a square box of black extruded-aluminum panels on the front, rear, and sides, rounded corners, and 6mm-thick top and bottom plates of natural aluminum. At just a smidge over 10.5”W x 3.5”H x 10.5”D, it’s wider by 2” or 3” than any of the three other desktop DACs I’ve had in my system (Hegel HD25, Ayre Acoustics QB-9, Eximus DP1). And at just under nine pounds, it’s also very light and easy to move from desk to rack. The very thorough and useful user manual is printed in English and German, and the warranty is three years.
On the front panel, going left to right, there are 11 small pin-buttons for the numerous operating options of the DAC 8. From the top left are the On/Off switch, then four buttons for input selections (S/P-DIF 1-2, S/P-DIF 3-4, TosLink/BNC, and AES/USB), a button for phase inversion, two buttons for controlling four various filter options, a button for wideband mode, and two more buttons for up and down volume control. There is also a 1/4” headphone jack on the far right. Above the buttons is a rectangular LED display that indicates each of the possible sampling rates from 44.1 to 192kHz and the volume level in numeric increments. An LED for each pushbutton flashes green or red to display which of its two settings is engaged. Thankfully, the main display also tells you which of any two algorithm options is engaged -- you don’t have to memorize which color means what or refer to the operating manual to know which setting is being used.
The rear panel is chock-full of connections. From left are a pair of XLR analog outs, a slide switch for disabling the volume control, a pair of RCA analog outs, the digital out, and the digital inputs (four S/P-DIF, TosLink, BNC, AES/EBU, and USB). At the far right is the IEC power inlet and below that an RS-232 socket. This means that the DAC 8 can, via the RS-232 port, control the on/off function of T+A’s Amp 8 when they’re used together.
Most of this wealth of connectivity was wasted on me -- other than the switch that disengages the DAC 8’s volume control, for this review I used only the RCA output, one S/PDIF input, the USB input, and the power socket. Finally, since the output resistance of the analog outs is a very low 22 ohms, the DAC 8 could drive my power amps directly, without use of a preamp. Not only did this shorten the signal path, it had audible consequences regarding transparency, soundstaging, and dynamic range. More about this later.
The DAC 8 has a terrific little remote that controls all of its functions, including powering on/off. About 3.5”L x 1.25”W x 0.5” thick, it fits snugly in the hand. What’s more, the casing isn’t just slick or pebbled plastic. It’s smartly jacketed in a semi-elastic polymer that seems to give infinitesimally under the touch, adding a patina of thoughtful elegance to convenience. Note, though, that the remote must have a clear line of sight to the DAC 8, otherwise it won’t work. I found I could control everything from my easy chair, about 9’ away. Even pointing it through a clutter of objects -- idle earphones, a coffee cup, a tape measure, etc. -- between me and the DAC 8, I never had any trouble getting the remote to work.
Though not quite plug’n’play (it requires the download of drivers for both Mac and Windows, and other software for Linux), the DAC 8 was easy enough to install in my system. I simply placed it on my desk next to my iMac computer and hooked it up with the various requisite wires. I powered it on, then downloaded the Mac driver, and clicked through the installation prompts. Next, I selected the DAC 8’s alias, “USB HS-Audio-A2,” from my iMac’s Sound menu, and I was in business. For playback software, I used Amarra 2.6 for a few weeks, then switched to JRiver Media Center 19.0.67 on the recommendation of a musician friend.
The only hiccups I encountered were when I upgraded my Mac’s Mountain Lion operating system from 10.8 to 10.8.5. Then, when I’d shut down the system and computer and fired it all up again the next day, the DAC 8 behaved as if it had no driver at all -- playback was full of skips and blips, and files would play at warp speed. After a few e-mail exchanges with T+A’s US distributor, Dynaudio North America, and using advice gathered from the German engineers, it turned out all I had to do was delete the Mac driver and reinstall it. All was well. Then, on odd mornings, for some mysterious reason obvious to only the computer literate, the DAC 8 would not immediately play any file I’d selected. I found I had to shift the volume up or down a click or two, or switch the input selection, then go back again. Other times, I had to re-click on the file selection, or Stop/Start it in JRiver once more. The DAC 8 would then immediately come to life and behave responsibly thereafter.
With all of its control features and settings, the DAC 8’s design might seem very tweaky. While I can’t claim to completely grasp all of its engineering details, I could certainly hear the results, and I heard them instantaneously. In operation, I tended to favor whichever Bezier or FIR setting made things sound fuller, with the midrange a touch forward without compromising resolution. But the same setting did not work for all or even most recordings. I had to hop around to find the right one for each recording. This intruded on the listening experience, creating a minor chore with each file I wanted to hear. But I got used to it. And when I used the DAC 8 and its volume control to directly drive my VAC Phi-200 power amp (with a claimed frequency response of 4Hz-75kHz and a power bandwidth of 13Hz-70kHz), the T+A’s wide-bandwidth option was a plus.
Performance with preamps
I first used the T+A DAC 8 to feed analog signals to two of my preamps -- a Lamm Industries LL2.1 and a deHavilland Mercury 3. It worked perfectly well with both, and its sound, with 16/44.1 signals, was consistently well balanced throughout the audioband, and equal to or better than what I got from my newly overhauled Cary Audio 303/300 CD player. The sound was both more resolved and somewhat easier on the ears, especially during tuttis of symphonic music, blasts of high notes from trumpets in jazz or classical recordings, and the top notes of operatic tenors and sopranos. Not surprisingly, with high-resolution files, the DAC 8 sounded clearly superior to CDs and ALAC files ripped from CDs, with greater clarity, dynamic range, and an increased sense of presence.
With jazz, especially, the DAC 8 had a lively, slightly midrange-forward sound and very clean highs. There was great ambience in “Summertime,” from the Modern Jazz Quartet’s The Last Concert (24/192 FLAC, Rhino). Milt Jackson’s vibes had shimmering, radiating tones and fine contrasts between notes as well as beautiful, seemingly endless harmonic decays. I turned the volume way up just to feel more of the music. “Peaches en Regalia,” from The Ed Palermo Big Band Plays the Music of Frank Zappa (16/44.1 ALAC, Astor Place), had brilliant waves of saturated choruses from the horns that were nonetheless immaculately detailed and almost separable, the baritone sax punching in the tune’s low-end foundation.
Just about every piece of piano music sounded grand -- crystalline in trills with crisp and precise attacks, a rich midrange, fine sustain, bountiful harmonics, and resonant, authoritative bass. This was true of Mozart’s Piano Concerto No.21, as performed by Eugene Istomin, with Gerard Schwarz conducting the Seattle Symphony (24/88.2 FLAC, Reference); and of Alfred Brendel’s performance of Haydn’s Piano Sonata No.53 in E Minor, H16 No.34 (16/44.1 ALAC, Philips). There were excellent dynamic contrasts, clear and ringing high notes, and a lovely midrange to Christian Zacharias’s piano (he also conducts) in the first movement of Mozart’s Piano Concerto No.19 in F Major, with the Lausanne Chamber Orchestra (24/88.2 FLAC, MD&G). I also found the Bezier/IIR setting helped with this recording, but with others, Bezier Oversampling might be better. I experimented with both, hearing differences that were mainly subtle, but important for optimizing.
Flipping through the Bezier and FIR settings and trying the phase inverter to find the right combination of settings benefited just about every recording, especially orchestral -- this was key for getting violins and massed strings to sound their best. For example, with Mozart’s Violin Concerto No.5, as performed by violinist Vesko Eschkenazy, with the Royal Concertgebouw Chamber Orchestra conducted by Marco Boni (24/96 FLAC, Pentatone), the Bezier 1 setting improved sweetness, focus, and timing as compared to Bezier 2. The orchestra sounded its most mellow and rich with Bezier 1, and Eshkenazy’s violin had both a biting incisiveness and a lyric sweetness that enhanced the music’s expressive range. Even better was Beethoven’s Symphony No.2, with Christoph Eschenbach conducting the Philadelphia Orchestra (16/44.1 AIFF, HDtracks). There was beautiful string tone in the masterful first movement, with good differentiation of the various sections, lightning transients and dynamic contrasts, and good scaling. Timpani strokes were thundering and authoritative in double fortissimo (ff) passages.
Performance direct to amp
Of all the audiophile virtues, only the DAC 8’s soundstaging seemed a tad off, and only occasionally. At those times, I would have preferred more depth and more solid imaging. It’s not that it was bad, but it seemed as if there was nothing special. But this was all before I discovered something remarkable.
When I dispensed with the preamps and ran the DAC 8 directly from its own analog volume control to my power amps, I got fabulous transparency, resolution, and touch. The sound was extraordinarily lively without being etched or having sharp-edged transients. More than that, there was a richness of depth to the soundstaging, and the imaging was consistently stable and solid. The sound was just so much more transparent and immediate than through any preamp, whether the deHavilland Mercury 3 or the Lamm LL2.1. With the system simplified in this way, any music I threw at it was now uniformly wondrous, pure, and pleasing. From orchestral and choral warhorses to piano concertos to live jazz recordings, from 16/44.1 to 24/192, the music flowed with a fine fidelity.
Diana Krall’s Sinatra-style swing in “East of the Sun (and West of the Moon)” from her Live in Paris (16/44.1 ALAC, Verve) had my head bobbing and my toes tapping. When the guitar, piano, bass, and drums reenter after the bass and piano solos, Krall swings hard on her piano and the whole band follows her, snapping crisply on the beat and accents. Nor was the cacophonous hard bop in Charles Mingus’s Mingus Mingus Mingus Mingus Mingus (16/44.1 ALAC, Impulse!) any trouble. The driving theme of “Better Get Hit in Yo’ Soul” can be particularly difficult for a slow system to capture. Mingus’s bass walks and thumps all over the beat, and there’s a bluesy, honking tenor solo about midway. Via the DAC 8 direct to the VAC Phi-200 stereo amp, I heard a shimmering horn chorus and relentless rhythm section behind doubled tenor and alto saxes, then the tenor and trombone doubling on the theme with the trumpet tailgating, anticipating, then dragging behind. The DAC 8 rendered all of this with superb and propulsive pace, rhythm, and timing (PRaT).
The sounds of strings, too, were fabulously rich and resolved. There was excellent tone, separation, and detail in Brahms’s String Sextet No.1 in B-flat Major, Op.18, performed by violinists Isaac Stern, Cho-Liang Lin, and Jaime Laredo, violist Michael Tree, and cellists Yo-Yo Ma and Sharon Robinson (16/44.1 ALAC, Sony Classical). In the first movement, Allegro non troppo, the six strings sounded sonorous, open, and vibrant. Stern’s violin and Laredo’s viola had rich harmonies in duet, and Ma’s pizzicato on his Stradivari cello had plenty of pluck and thunk. And when Ma joins in on the main theme, I felt his assertive bowings as a vibrant pulse in my own chest. It all sounded very dramatic, yet completely natural.
Male and female voices came off spectacularly well. “Here We Go Again,” sung by Nora Jones and Ray Charles on the latter’s Genius Loves Company (16/88.2 FLAC, Hear Music), had terrific imaging and timbral specificity throughout. Charles wailed and moaned in bluesy, gospel-inflected singing, Jones answering him in smoky, seductive tones. Peter Green’s voice in “Need Your Love So Bad,” from Fleetwood Mac’s The Pious Bird of Good Omen (16/44.1 ALAC, Columbia), sounded relaxed, supple, and characteristically thinnish, yet not without its own charming authority. And his screams and wails in his “Black Magic Woman,” later famously covered by Santana, were beautifully clear and expressive. Even better was Raul Malo’s singing of Roy Orbison’s “Blue Bayou,” from Malo’s The Nashville Acoustic Sessions (16/44.1 ALAC, CMH). Though Malo begins the tune in baritone range, he quickly climbs to pure yodeling highs with a light vibrato. There was a lovely, slightly forward push to the midrange that flattered Malo’s tenor and, I think, helped make more evident some nice microdynamics in his vocal nuances.
For more than 30 years, one of my favorite pieces of music has been Brahms’s A German Requiem, a composition for full choir and orchestra. I own numerous recordings of it, but one new to me, despite its age and fame, is Otto Klemperer’s, with the Philharmonia Orchestra and Chorus, from 1961, in a new hi-rez download (24/96 FLAC, Erato/Warner Classics). Via the DAC 8, the choir in the opening movement, “Selig sind, die da Leid tragen,” sang airily, spread out across a soundfield of good depth and width that extended just outside each speaker. The double basses provided a grave drone underneath, while the rest of the orchestral strings played a warm but elegiac accompaniment. Although the German words were clearly intelligible, the voices, projecting both power and delicacy, weren’t quite individual but appropriately collective, organized in their proper sections. Woodwinds were all clear and sweet. In the second movement, “Denn alles Fleisch, es ist wie Gras,” after the somber opening, with orchestral strings playing richly yet quietly, there came great pulses of choral sound. The basses sang gravely, matching the stateliness of the cellos. Sopranos and altos responded in soft clouds of billowing song. The movement ended with a procession-like, gradual accelerando from the double basses, joined by the entire choir singing full out, then trailing away in lovely contrasts of each sectional register. I felt an almost holy hush deep inside my bones from these quiet, still voices of calm.
Comparison and performance as a headphone amp
My reference desktop DAC is the similarly priced Eximus DP1 ($3200), a fine digital component known for its eye-catching industrial design and ease of use (it’s plug’n’play for Macs). When I ran the Eximus DP1 direct to the VAC Phi-200 stereo amp, it sounded more on the “solid state” side, while the DAC 8 sounded more “tube-like.”
The Eximus DP1 was not as refined as the DAC 8 when directly driving an amp, and its volume control wasn’t of the same quality as the T+A’s -- it really needed to be run through a preamp. Its sound more closely matched the DAC 8’s when I did that, strings sounding much more natural in Brahms’s A German Requiem and String Sextet No.1. But I’d still say that the DP1’s basic sound is cooler, perhaps speedier with transients, than the DAC 8’s, with all instruments a touch more forward and not quite as fleshed out in the midrange. In the A German Requiem, the Philharmonia Orchestra and Chorus seemed lean and recessed compared to the DAC 8’s presentation. There were also occasional hints of distortion with the DP1. The bass could be flabby and overblown at times, and the treble could break up at dynamic peaks when the choir sang full out.
But with Eugene Istomin’s performance of Mozart’s Piano Concerto No.21, the DP1 was quite comparable to the DAC 8 in rendering the sound of the piano -- trills were crystalline with good harmonics, and there were fine attack and decay transients. But the violins sounded a bit washy at times, not as open or as warm as through the DAC 8.
With jazz, such as Mingus’s “Better Get Hit in Yo’ Soul,” instrumental attacks sounded even more explosive via the DP1, the tenor saxophone more detailed, with microdynamic shifts more evident, and the trumpet more brilliant in tone. Mingus’s bass stood out more in the mix, and seemed tighter and talkier with the DP1. Throughout, there was more treble sparkle and shine. The Eximus DP1 was capable of more extension at the frequency extremes, and its PRaT abilities were even more evident than the DAC 8’s. The coordination between drums and bass was more emphatic, and the swaggering horn choruses were just as cacophonous and wild as through the T+A.
I definitely preferred the T+A DAC 8 for chamber, choral, and orchestral music, though I might want the Eximus DP1 (if run through a preamp) for jazz and rock. Finally, if my memories of the sound of the Hegel HD25 remain accurate, the T+A DAC 8 almost exactly split the difference between the leaner Eximus DP1 and the warmer, smoother Hegel. While the Hegel excelled with the sounds of strings and other acoustic instruments, I don’t recall that it was as clear, dynamic, or purely emotional as the DAC 8. And whereas the Eximus DP1 was definitely punchier, more fleet, and more emphatic with rhythms, the DAC 8, run direct to a power amp, was no slouch in those areas and sounded much more natural with acoustic music.
As far as features, the analog outs are the same for both units on hand, but the DAC 8 has many more adjustments and inputs, an excellent remote control, and excels when run direct to a power amp. The DP1 has filter enhancement (bass boost) for headphones, a mini-jack as well as a 1/4” headphone jack, a smaller footprint, and, generally speaking, better looks and a much more ergonomic design for hand operation with its power switch, larger pushbutton controls, and dulcimer-shaped volume dial. The DAC 8’s front-panel controls are all tiny pushbuttons with LEDs. I’d say the DP1 is more truly a desktop component; the DAC 8’s wider, squarer shape, superior feature set, and relatively sophisticated remote make it a ’tweener design equally suited to placement on a desktop, in a rack, or in a living-room console.
As a headphone amp, the DAC 8 has a lot to recommend it. I spent a good month listening via three different pairs of headphones and comparing its sound to those of some pretty good head amps. The DAC 8 had lots of drive and oomph, not to mention fine resolution. I found it superior to the Eximus DP1, and more refined than my Heed Canamp, a standalone component with more gain and slam. The DAC 8 drove two fairly insensitive sets of ’phones -- Audeze LCD-3 and Sennheiser HD 650 -- to good levels and sounded even better with the more highly resolving Ultrasone Edition 8. In terms of resolution and spectral balance, the DAC 8 approached the performance of a Pathos Aurium hybrid headphone amp (review forthcoming), sounding as warm and clear, and nearly as rich with most music, but without the Aurium’s superior drive or pure ease with everything.
T+A Elektroakustik’s DAC 8 strikes me as a product very much like the BMW 1800 sedan of the mid-1960s -- a very practical yet innovative German import blessed with superior power, superb engineering, and clever touches of serious luxe. Many may not yet have heard about the DAC 8, but I’m betting it won’t fail to soon attract attention. Compared to the many feature-poor plug’n’play units now popular, the DAC 8’s numerous controls and filters might at first perplex, but they all make perfect sense in terms of what they do for the sound. With both synchronous and asynchronous USB operation, galvanic isolation, and a complete absence of op-amps in the signal path -- thus eliminating the need for negative feedback, which can compromise linearity -- the DAC 8’s build quality, sensible versatility, and sonic performance are just plain outstanding. I got excellent sound with all genres of music.
If you’re in the market for a desktop or console-top DAC, I strongly recommend checking out the T+A DAC 8. It can be the solo source for a superb three-piece system of DAC-preamp, power amp, and speakers. And as the hub of a digital system it’s completely flexible, accepting USB from a computer, S/PDIF and optical systems from other digital sources, and works terrifically with most any headphone out there. I loved it. I’m keeping it.
. . . Garrett Hongo
- Digital sources -- Cary Audio 303/300 CD player, Apple iMac computer with Eximus DP1 DAC
- Preamplifiers -- deHavilland Mercury 3, Lamm Industries LL2.1
- Power amplifiers -- deHavilland KE50A monoblocks, MBL 8011-S stereo amp, VAC Phi-200 and PA-100/100 stereo amps
- Speakers -- Sonus Faber Grand Piano Home, Von Schweikert VR-5 HSE
- Headphones -- Audeze LCD-3, Sennheiser HD 650, Ultrasone Edition 8
- Headphone amplifiers -- Heed Canamp, Pathos Aurium
- Speaker cables -- Siltech 330L and 330L jumpers
- RCA interconnects -- Siltech 330i
- USB cable -- Wireworld Platinum Starlight
- S/PDIF cable -- Wireworld Starlight
- Power cords -- Cardas Audio Golden Reference, Harmonix XDC Studio Master, Silent Source Signature, Siltech Ruby Hill II and SPX-800
- Power conditioner -- Pranawire Linebacker
- Power distributor -- Siltech Octopus 8
- Accessories -- Box Furniture S5S five-shelf rack, edenSound FatBoy dampers, HRS damping plates
T+A Elektroakustik DAC 8 Digital-to-Analog Converter
Price: $3250 USD.
Warranty: Three years parts and labor.
T+A Elektroakustik GmbH & Co. KG
Phone: +49 (0)52-21/76-76-0
Fax: +49 (0)52-21/76-76-76
North American distributor:
Dynaudio North America
1140 Tower Lane
Bensenville, IL 60106
Phone: (630) 238-4200