AUDIO MIRROR TUBADOUR MKIV DAC

If one were to assume I have a bias about digital–to–analog converter architectures, which I do, it would speciously point to non–oversampling DACs as my preference. Of late, I have reviewed the Merason frerot, MUSICIAN’s Pegasus and Mojo Audio’s Mystique X SE. All of these are firmly in the non–oversampling (NOS) camp. As pop burnout Britney once sang, “Oops!... I Did It Again”.

Of the aforementioned products, the first and last in the list piqued my interest for the two differing ways they smoothed the aural edges of the incoming data, making for a rounder, sometimes less biting delivery. Cost wise, at $1450 the Merason is affordable while the Mojo Audio’s cool $10k price tag would cause all but the most comfortable to give pause. The topic of today’s review sits snugly in between. At $3,500, the Tubadour IV SE DAC, henceforth also the “T4,” is well within reach of many if not most music enthusiasts seeking digital enlightenment.

Hand built by Vladimir Bazelkov and his tiny team at Audio Mirror, the Tubadour IV SE is his fourth generation of R–2R, non–oversampling DAC. The SE designation stands for Signature Edition, though there is no Standard Edition as with past models. The T4 is designed and built in the US, and features a USB re-clocker, ultra–low noise power supplies

and two out–of–production Analog Devices

AD1865 18 bit monolithic multibit DAC chips. The AD1865 is a stereo device, and using both internal channels for each of the T4’s channels yields better linearity and lower noise. Multibit designs combine R–2R and delta sigma techniques on the same device. Bazelkov’s USB implementation starts with the industry standard XMOS chip, then re–clocks the data using a high quality, low noise/low phase distortion crystal. As you may have noticed in past reviews of mine, clean power supplies are essential to higher fidelity. The T4 incorporates separate, very low noise low power supplies for USB and its reclocker, and an “ultra low noise,

MOSFET power supply” and regulation for high voltages, according to Bazelkov. The plain jane, all aluminum casework is shared by Audio Mirror’s LINEA ultra wideband, hollow state preamp. As with the pre, on the T4 the user interacts with the product via refreshingly simple controls; a rotary power knob and an input selector. That’s it! No noise–inducing LCD display, no multicolored Christmas lights. The signal itself is also handled with care. Silver wires carry the music for all signal paths, and silver–plated copper makes up the rest. Once the raw signal exits the double AD1865 DAC chips, special resistors are used for the “I/V” or current–to–voltage conversion. The tube analog section has no capacitors in the signal path; “…the best capacitor is no capacitor,” Bazelkov opines. Lundahl output transformers were selected, after many trials and tests, to provide impedance matching for the vacuum tube. The designer holds a minimalist outlook, “…not to save parts” (reducing the cost of materials) but because “…it’s the best sounding approach.” The tube was selected from many different options, types (pentode/triode) and models for the same reason. “It’s the best sounding with the most linear and neutral nature. It happens to be an ECC88 which is a very popular tube and readily available. Many people ask why is there one tube for both channels. They don’t realize that this is a double triode. So, yes; one per channel.” An ECC88 should last around 5,000 to 10,000 hours, depending on whether it’s New Old Stock (also “NOS”) or from new production. Bazelkov mentioned that the Russian 6H23P is probably the second best sounding tube after Siemens or Tesla, not JJ Tesla he stresses.

On to the music…I ran the T4 through its paces, playing locally stored files as well as Qobuz streams. From Red Book rips and DXD files to recent releases, it was most pleasurable to sink into some quality listening. Mad Buggle man Trevor Horn produced one of my all time fave pop songs, the 1991 hit “Crazy” by Seal. It has been endlessly remixed and was rereleased in 2022, with aggressive re–equalization and a