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The ATM-1E has just four main user controls: a pushbutton for power, separate attenuation knobs for the left and right channels, and an identical-looking knob for checking and bias, labeled "IP Monitor" ("I" for current, "P" for plate). This five-position knob—"Operate" plus a position for each power tube—lets you adjust the plate current using a meter and four trim pots on the top panel, adjacent to the choke enclosure.

Installation and setup
I positioned the easy-to-lift ATM-1E on top of four A/V RoomService Ltd. Equipment Vibration Protectors (EVPs). Norman Varney's EVPs…

Description: Tubed stereo power amplifier. Tube complement: One 12AT7/(ECC81), two 6CG7/(6FQ7), four EL34/(6CA7). Inputs: Stereo pair single-ended (RCA). Output power: 35Wpc into 4 or 8 ohms (15.3dBW & 12.3dBW). Input sensitivity: 700mV (35W). Input impedance: 100k ohms. Output impedance: two taps, 4 ohms and 8 ohms. Frequency response: 20Hz– 30kHz (–1dB). THD (1kHz) <5%. Damping factor: 6.7. Power consumption: 250VA.
Dimensions: 14.37" (365mm) W × 8.85" (225mm) H × 12" (305mm) D. Weight: 47.39lb (21.5kg).
Serial number of unit reviewed: R06006.…

Analog sources: Thorens TD 124 turntable, Korf TA-SF9R tonearm, Kuzma CAR-30 MC cart; J.Sikora Standard Max Supreme turntable, J.Sikora 9" KV9 MAX Tonearm, EMT JSD Pure Black MC cartridge.
Digital sources: HoloAudio May DAC, Sonore opticalRendu, Roon Nucleus+, Small Green Computer power supply, TRENDnet switch, Apple iPad mini.
Preamplifiers: Shindo Allegro line; PrimaLuna EVO 100 phono, Manley Chinook phono, Tavish Audio Design Adagio phono.
Power amplifier: Rogue Stereo 100.
Loudspeakers: Volti Audio Razz, Voxativ Ampeggio 2024, DeVore…

I performed the measurements of the AirTight ATM-1E with my Audio Precision SYS2722 system. Before I started the testing, I followed the instructions in the manual to optimize the bias for the four EL34 output tubes. There are two output transformer taps, labeled High and Low instead of the usual 8 ohms and 4 ohms. I performed a complete set of measurements at each of the taps. The attenuation controls (one for each channel) were set to the minimum for the tests, ie, to the highest gain.

The ATM-1E's voltage gain into 8 ohms was 29.4dB from the High tap and…

In the Executive Lounge, a new Pure Fidelity Symphony turntable ($21,995) with a DS Audio W3 cartridge ($5000) juiced the new EMM Labs DS-EQ1 V2 optical equalizer ($12,500), with digits relayed via a new Bel Canto Design Black DAC ($40,000), balanced by an Innuos ZEN NG server ($12,000).

The Pure…

At the heart of this soothing sonic assemblage was a Linear Tube Audio Aero DAC ($3800) feeding a Linear Tube Audio LTA Z40+ integrated amp (from $7650), which in turn drove the exquisite MC Audiotech TL-8 loudspeakers ($15,000-$17,000/pair). Wolf Servers and ArgentPUR Cables completed this refined, sophisticated ensemble.

A Merason Reuss DAC ($6000) and Innuos Pulsar streamer ($8000) rolled out the digits while the new Qualiton 300B integrated amplifier, a lovely push-pull amp delivering 25Wpc via two 12AX7EH Gold, four 12AT7EH Gold, and four 300B EH tubes ($11,000) drove the new QLN One v7 standmount loudspeakers ($12,000/pair), using a proprietary 5.5” mid-woofer and a 25mm “wide surround” tweeter.

Conditioning and cabling consisted of a…

What I noticed most during the review period was the extraordinary volume of data the 701T was vacuuming off those pits and lands and turning into music. As I have gotten to know it better, what I've noticed most is how the 701T sorts and delivers all that data…

MQA via JPS Labs in binaural
I only own one MQA recording, but it's a doozy. It's on a CD, and surely one of the most real-sounding live recordings I've encountered.

Inside the Moment is a luxuriously packaged Chesky Records production (Chesky Records CD JD397) of Camille Thurman singing and playing saxophone, recorded live at New York's Rockwood Music Hall with a B&K binaural head feeding an MSB A/D converter, engineered and mastered via the sharp, wise ears of Nicholas Prout.

Before I acquired this spectacular CD, I'd only experienced MQA via streaming on Tidal…