The Present Day

Continued from here
There’s a company called ‘Audio Mirror’ based in Eden Prairie Minnesota, and they’ve been in my peripheral vision for a number of years. I started to notice Audi Mirror when I had my first high-efficiency horn system some years ago and began looking around for flea-powered amps. Browsing through the Audiogon classified’s ‘tube amp’ section, Audio Mirror’s 45 watt SET monoblocks would show up once in a while and I was attracted to the shiny chrome aesthetic like a Magpie is to a silver coin.

Allnic Phon reviews
Audio Mirror Tubadour III SE DAC review

Flying in Stealth Mode…

The Tubadour DAC started life in its MKI iteration way back in 2005. But I have to say, it was flying completely under my own personal radar until the MKIII version caught my attention in 2019. Had you asked me about ‘Audio Mirror’ up until a few months back, I would’ve bet my cat on them being a one-product company.

Audio Mirror

If you pay a visit to Audio Mirror’s website at www.AudioMirror.com, you’ll find an interesting story by Audio Mirror owner and chief designer Vladimir Bazelkov (Vlad), on how the Tubadour DAC came to be.

Now in its third iteration and with an up-specified SE model, the Tubadour isn’t a product that has been thrown together in a hurry to take advantage of some newly evolving trend. As is obvious from the minimalist product line and the 15-year evolution of the Tubeadour from MKI to MKIII status, progress at Audio Mirror HQ is slow and methodical, almost Darwinian one might say.

Yet the evolution of a digital product birthed on Darwinian principals would almost certainly have emerged with its prevailing DNA being similar to those products exhibiting the most success in the marketplace in our present times.

Not so with the Tubadour. Rather, it’s almost a step backward in design philosophy; a DAC which has taken many years’ R&D to come to fruition yet pitches itself in direct opposition to the mainstream approach of D to A conversion: Non-oversampling.

Not that the Tubadour sits alone as a non-oversampling DAC, there are others on the market that do the same thing. Audio Note and Wavelength Audio are just two from at least twenty manufacturers with non-oversampling DACs. But there are some important differences between most of the rest of the pack and the Tubadour, as we will come to see.

Digital And Tubes

The second thing of note with the Tubadour is its use of tubes. It was J Gordon Rankin who said “Tubes are great with digital. Solid-state will pass all kinds of high-frequency energy into the music which makes it sound sterile. Also with solid-state, it takes a ton of transistors to make it work. I can do the same thing with one tube and either a transformer or a reactor. Sure it costs more but it sounds incredible.”

I can’t challenge the above statement on a technical level, and it remains to be seen how tubes impact the sonics of digital, and how the Tubadour MK III SE, with its tube IV conversion stage, competes with all-digital units.

Tubes used in the DAC are 5977 subminiature tubes mounted on a special tube adaptor, which is plugged into a regular 9 pin tube socket. So you can easily unplug the adaptor and use regular 9pin tubes if tube rolling is your thing. 6N1P, 6DJ8, ECC88, 6922 and 6H23P can all be accommodated by the Tubeadour DAC. 

The Audio Mirror Tubadour III SE ($2500 ’Special Edition’) is the model we received here for review. It uses the same digital engine as the base model, but with superior quality components in key areas, including Duelund caps in the signal path, Z-Foil Vishay resistors in the IV and tube section, lower noise power supplies for the USB and I2S inputs, a Furutech Gold IEC power inlet and IsoAcoustics “GAIA” vibration absorbing/isolation feet.

In some part, the evolution from Base Model to Special Edition was consumer-driven, and one might even say ‘consumer developed’. I came across at least one forum thread where users of the base Tubadour were beginning to tinker with their units, switching caps and resistors, and trying various higher quality components without changing values. A consensus began to emerge on which component changes had the most profound and positive effect on the sound quality of the unit, and the results were fed back to Audio Mirror in the form of “requested upgrades”. As a business owner and engineer, I found this area of the Tubadour’s evolution quite fascinating and it’s one of the things that lead me to make contact with the company.

At the time of reviewing, the Tubadour III SE provided compatibility with all common playback formats in the range 16-32 bit and up to 384kHz. It plays natively in the PCM format hence relies on the “convert on the fly” technology found within most popular music players, including Audirvana, Amarra, Foobar, Roon, Euphony, and more. The Tubadour DAC does not have MQA capability.

Connectivity options cater to all of the common standards – AES, Coaxial, Optical, and USB, with I2S input as an option. The base Tubadour III comes standard with unbalanced outputs, balanced outputs are optional.

Of the process involved in deciding on the best conversion engine for his new product, Mr. Bazelkov describes a long journey lasting many years, one where ESS Sabre DAC chips, Delta sigma DACs, Over-Sampling chips, were pitched against Non-Oversampling DACs, single bit and multibit. Many chipsets were analyzed for their sound quality, all emerging sonically inferior to the Analog Devices multibit R2R DAC.

 

Setup And Integration Into My Review System

Feeding into the Tubadour was my Aurender N100H, connected via USB, and my Cambridge Audio Azure 851C used as a CD transport and connected using spdif. I played with a stripped-down 2012 Macbook Pro using its USB output to the Tubadour, and though it worked well the Aurender performed better on FLAC files pulled from the same source and better still on FLAC files pulled from its own internal Hard drive. However, I do have a large number of DSD files on one of my 4TB NAS drives, so I spent time with those, accessed via the Macbook Pro and handled by Audirvana+ software.

For direct comparisons, I switched in and out the excellent value Ayre Codex DAC and my Sim Audio Moon 380D DAC. I also spent a little time comparing the DAC in the Cambridge 851C to the Tubadour.

I used many different cables during the review, both input and output. I initially struggled to find the right USB cable to use between my Aurender and the Tubadour. Forum chatter pointed me toward Curious Cables, a brand with which I was unfamiliar. Located in Australia, I was unable to get a cable to the USA in an acceptable timeframe, and I couldn’t find one anywhere on the used markets.
I settled on a newer Transparent USB Digital, which at $700+ was almost half the price of a Base Model Tubadour!
For spdif, I used the Synergistic Research Digital Corridor No. 2 RCA Digital Coaxial cable mostly.

From the DAC to my preamp, I experimented with the Anti-Cables Level 3.0 RCAs, which, when combined with the inherent warmth of the Tubadour, turned out to be a little too warm overall. Both Tara Labs RSCs, and Harmonic Technology Pro Silway IIIs offered up a slightly more neutral presentation, with the latter becoming my preferred RCA cables with the Tubadour.

For power cables, I tried the ESP Reference and the WyWires Blue Juice II. I couldn’t discern any real difference, so I retained the WyWires cord for the remainder of the review.

For isolation, I generally tie myself in knots experimenting with different tweaks and isolation/coupling devices, usually ending up with either Audio Points or Mapleshade heavy brass footers, depending on the size and weight of the component. In this case, I preferred Audio Points over any other devices, including the stock feet.

 

Listening

The unit came to me with around 50 hours’ use, but I let it cook for another 100 hours or so before taking anything I heard too seriously. I also cycled the unit on and off many times during the preliminary review phases to give the caps a little more action. The Tubadour does benefit from at least twenty minutes warm-up time from cold, but there’s nothing unpleasant about the sound it produces from the get-go.

For the first three days or so, I spent a lot of time listening to CDs played via the Cambridge Audio Azure 851C connected via the Synergistic Research Digital Corridor No. 2 active spdif cable. I had things set up to facilitate a quick switch of the spdif output to the Sim Audio Moon 380D, with the 380D feeding a second input on the Thor Audio preamp. Switching between the Moon and the Tubadour in this manner made it easy to lay down some quick and useful reference points.

It took only a few moments listening to the title track of the remastered CD of Dire Straits’ ‘Love Over Gold’ to hear the tube effect in play with the Tubadour DAC. The sound was warm and inviting and Knopfler’s guitar was rendered with a beautiful tone.

Through the Tubadour DAC, the tone and texture of guitar notes sounded real and unimpeachable, whereas the attack and decay element of the plucked strings seemed just a little slow and a little muted. Through the Sim Audio Moon 380D, guitar notes came over with less of the fleshiness and tonal richness of the Tubadour, but there was a slightly elevated vibrancy to the sound via the 380D, with a more vivid sense of attack and decay from the plucked nylon strings.

On the ‘Private Investigations’ track, these initial observations were supported and further highlighted during the guitar/keyboard/drum crescendo towards the end of the piece. The Tubadour carried itself well through the quieter passages of the track where the emphasis is on Knopfler’s virtuoso guitar playing, but on the explosive ending, the Sim Audio delivered more of a visceral impact.

Bass was typically tube-like, though not in any negative sense. Listening to The Rite of Strings, a superb collaboration by Al Di Meola, Stanley Clarke and Jean-Luc Ponty, Clarke’s double bass notes were deep, ripe and plummy in contrast to a more taught and dry presentation through the 380D, ultimately more natural and believable, closer to what I would expect from a real instrument versus a recorded facsimile.

Cycling through my usual catalog of reliable review CD’s I would often start a listening session with note-taking intentions in mind, only to find myself several hours later with nothing committed to paper. In fact, I held on to this review sample for far longer than I ought to have, simply because it rendered me so unproductive when it came to the job I had committed to do!

Venturing into the classic rock genre tracks like ‘Red Barchetta’ and ‘The Camera Eye’ from the Rush ‘Moving Pictures’ album captured the essence of the Tubadour with a full and solid presentation lacking nothing other than perhaps a little more scale and depth. Yet switching to more complex music with more layered vocal and instrumentation, such as that found in the remastered Queen II recording, the Tubadour made certain tracks a little too ‘comfortable’, with an obvious neutering of the glassiness from the high-frequencies and a more homogenized and less distinct rendering of the layered vocals and guitar orchestrations courtesy Mercury/Taylor/May. 

Switching around inputs, sources and cables highlighted the Tubadour’s requirement to be fed good signal in order to thrive. This unit took more effort than I usually invest in the review process to sound its best, so I recommend future owners of the Tubadour not make hasty judgments without having first explored a variety of sources and configurations. Initially, I found that comparing the sound from my Aurender via USB and my CD player used as a transport via Spdif, resulted in too close a call between the two disparate sources. I’d expected far better from the Aurender, with its onboarding of playback data into a digital buffer, versus the jitter-laden continuous stream of data from the transport, where in fact the two were quite close, a little too close. Experimenting with USB cables I was able to open up more of a respectable margin between the two, but I was never ultimately satisfied that the Tubadour was nailing it with USB/Aurender. I brought owner/designer Vlad into the discussion at this point and he was less than complimentary about the audible prowess of the Aurender, suggesting in no uncertain terms that his baby needed a better signal than that available from the Aurender N100H. I’ll grant him that the Aurender’s sonics must be slightly compromised by its versatility, given its list of features and its somewhat modest $2700 MSRP, but I found it to be quite capable of leapfrogging the CD transport’s sonics when used into the Sim Audio 380D. 

So, though I improved matters by switching USB cables from what had worked well with the 380D to something I wasn’t really happy about purchasing for an unpaid review ($700 Transparent USB Digital), I’m still hesitant in giving the Tubadour DAC the highest of marks for ease of attaining system synergy and overall compatibility. I’m sure your mileage will vary.

Reflecting back on my time with the Tubadour it was clear that during non-analytical listening sessions I always favored simpler recordings over anything denser and more complex. Listening to John Martyn’s ‘Solid Air’ recording both on CD and Aurender playback showed the Tubadour in its best possible light. Martyn’s vocal was grungy and raspy then smooth and delicate as needed, and his guitar tone and the sheer presence of the instrument in the mix were among the best I’ve heard from digital.

Some of you will no doubt prefer the tighter and marginally more extended bass presentation inherrent in the best solid-state, as you’ll likely appreciate the impression of a more extended and airy high. I’d like to be able to say that the Audio Mirror Tubadour DAC somehow bridges the gap between great tubes and great solid-state, in the same way I found the remarkable Allnic Audio L-5000 DHT preamp to bridge that gap, but it does not. Yet I really enjoyed the way this little box interprets music, in much the same way as I enjoy the rendering of data from my Conrad Johnson CT-5 preamp or my Thor TA-1000 preamp. There’s a certain integrity one senses from well-implemented tube designs which in my experience is less apparent in anything solid-state. Seamlessness and cohesion, depth, body, palpability, etc, each go some way to expressing the resultant sonic advantages of tubes over solid-state, but ‘musicality’ is the manifestation of these adjectives and musicality is abundant with the Audio Mirror Tubadour MK III SE DAC.

 

In summary – 

Audio Mirror Tubadour SE MK III DAC – Strengths and Weaknesses

  • The Tubadour has wonderful purity of tone and an ability to resolve hidden detail – a solid foundation for the suspension of disbelief
  • Its imaging ability is good yet it doesn’t create soundstage depth and width as impressively as the more expensive Sim Audio 380D
  • It is, in some sense, a stereotypical vacuum tube device, imbued with the strengths and hampered by the weaknesses of tubes in much the same way as that which one might find in a good tube preamp.
  • When all the nitpicking is over, one can sit down and enjoy the music this little machine produces without any sense that there’s something gratuitously amiss with the design principal and the execution of that principal within this device. As a machine for transposing the ugliness of a digital data stream into the real beauty of music, it is as convincing a machine as most of us will ever want or need.

Rooze

March 2020

 

EQUIPMENT USED IN THIS REVIEW INCLUDED:

DIGITAL
Audio Mirror Tubadour MKIII SE DAC
Ayre Acoustics Codex DAC
Cambridge Audio Azure 851C Player/DAC
Sim Audio Moon 380D DAC
Aurender N100H Server
MacBook Pro
Seagate / Western Digital USB/NAS
Various digital cables and accessories
PRE / POWER
Thor TA1000 MKII preamp
Thor TPA 60 Monoblocks
Edge NL10.2 Power Amp
LOUDSPEAKERS
Dunlavy SC-III
Aerial 7b
Aerial SW-12 Subs (x 3)
CABLES AND ACCESSORIES
Harmonic Technology Pro-Silway III RCA, Bogdan Audio Toto RCA’s, Tara Labs Master Speaker Cables, Anti-Cables 2.1 speaker cables, various isolation accessories etc etc.