I used DRA Labs' MLSSA system, a calibrated DPA 4006 microphone, and an Earthworks microphone preamplifier to measure the GoldenEar T66's quasi-anechoic frequency- and time-domain behavior in the farfield. I raised the speaker on a dolly and a stack of 2 × 4s so that the tweeter was midway between the floor and ceiling. Because of the geometry of my listening room, where I performed the measurements, the microphone distance was 1m rather than my usual 50". I used an Earthworks QTC-40 microphone for the nearfield responses and Dayton Audio's DATS V2 system to…
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This paragraph from Linear Tube Audio's website description of their new Aero DAC sets the tone for the story I'm about to tell. "After trying various options, we chose the Analog Devices AD1865 R2R DAC chip, which is sometimes called the 'vinyl DAC,' for its organic sound. It is a non-oversampling DAC, with no digital filters. The AD1865 is much-loved by audiophiles and is used by at least one hi-fi company in a flagship DAC costing over $150,000."
Check the forums and you find that the AD1865 chip is also a heavy DIY favorite. Home brewers are attracted to this discontinued, "obsolete"…
The preternaturally talented Neveu (1919–1949) was playing her soul out on a made-in-1730 Omobono Stradivari—Omobono was one of Antonio's sons—and its rich tones came through my speakers dense and rub-my-fingers-together tactile. The Aero strongly emphasized bow-on-string textures, which emphasized Neveu's tone, making for a sensuous, compelling Ginette Neveu listening experience.
To my delight, LTA's DAC presented these remastered pre-1949 recordings with that Kodachrome tone I've come to associate with NOS R-2R converters. Best of all, the Aero added a faint halo of tube…
Sidebar 1: Specifications
Description: R-2R D/A processor based around the 18-bit Analog Devices AD1865 chip, with 12SN7/6SN7 output tubes and no filters, feedback, or oversampling. Formats: Up to 24/192 PCM. Output voltage: 2.2V RMS RCA, 4.4V RMS XLR. Digital inputs: USB, S/PDIF on RCA, and TosLink. Output impedance: 70 ohms unbalanced (RCA), 140 ohms balanced (XLR). Power consumption: 32W in operation, 7W standby.
Dimensions: 17" (431mm) W × 3" (76mm) H × 10" (254mm) D. Weight: 15lb (6.8kg).
Serial number of unit reviewed: 240422. Manufactured in USA.
Price: $3950. Approximate…
Sidebar 2: Associated Equipment
Analog sources: Dr. Feickert Analog Blackbird turntable with Sorane SA1.2 tonearm with Dynavector XX2 moving coil, plus Nagaoka MP-110 and "homebrew" MP-200, and Audio-Technica's AT-VM95E moving magnets. Pulse EMT 912-HI tonearm with EMT's JSD6 moving coil.
Digital sources: Denafrips Terminator Plus DAC, HoloAudio May and Spring 3 DACs, dCS Lina DAC with Master Clock; Onkyo C-7030 CD player, TEAC VRDS 701T transport, Roon Nucleus+.
Preamplifiers: HoloAudio Serene; PrimaLuna EVO 100 and MoFi MasterPhono phono stages.
Power amplifiers: Parasound…
Sidebar 3: Measurements
Before I started testing the Linear Tube Audio Aero D/A processor, I carefully installed the two 12SN7 tubes and made sure the tubes' heater voltage had been correctly set with the rear-panel switch. I measured the Aero with my Audio Precision SYS2722 system, first using optical and coaxial S/PDIF data, then repeating some of the tests with USB data sourced from my MacBook Pro. (The TosLink input didn't lock consistently to data sampled at rates higher than 96kHz.)
The USB Prober utility identified the D/A processor as "LTA Aero" from "LTA," with the serial…
Forty years ago, as I was starting out on my audio journey, I railed against the flashy mainstream audio gear of the day. To me less was more, and I tried to convince my friends that my small, austere British-made audio rig, including what my friends jokingly called my Lynn Swanndek turntable (after the Steelers wide receiver), really did sound much better than their big silvery Japanese stacks loaded up with shiny knobs, switches, and meters. Audio was all about the sound after all, and I wasn't interested in some dazzling visual display that had nothing to do with what I was hearing. I…
SME’s Kathryn "Kat" Ourlian deejays a turntable shootout. Photo by Michael Trei.
One August night in 1965, I parked in the driveway of my best friend Derf Marko's house and let myself in the back door. As I entered, I could see to the bottom of the basement stairs, where I observed a loud pulsing darkness with plumes of agreeably acrid smoke floating up through the stairwell. Back in the darkness, I heard Derf/Fred and another person making declarative statements in loud unintelligible bursts. When I reached the bottom of the stairs, Marko's basement rec room looked like a trashed-out…
The first cable in front of a source—particularly a 0.3mV output source like the XX2—is unavoidably a factor in overall system sound. It is easy to observe this first-cable effect with digital converters and phono stages, both of which can be picky about wires and tend to favor one brand of interconnect over others. I figured tonearm cables could be even more picky.
I know that small-signal audio junctions, like the one at the output of a phono cartridge, are fraught with electromagnetic challenges that (I presume) different cables will handle differently. The prime challenge…
"Hybrid" technology—specifically, mixing tubed and solid state in the same amplification device—stirs a deep desire for many enthusiasts. It has the potential to embody a perfect blend: the tonal liquidity, presence, and spaciousness of tubes coupled with the power and dependability of solid state. It's potentially an end-game technology.
Still, I have long remained skeptical. I am, I confess, a certain kind of audiophile, a blend of purist and traditionalist. I favor older technologies and simpler circuits. Amplifiers—including integrated amplifiers—should be tubed, input to output.…