I would never purchase an integrated amplifier with a DAC or phono stage residing in the same box. To me, that's like buying an active loudspeaker.…
search
In my personal life I prefer the minimalist, one-box architecture of integrated amplifiers. Always have. Before I started writing for Stereophile, my only audio system consisted of a pair of 15 ohm Rogers LS3/5a loudspeakers (with factory wall mounts) and an ancient Creek integrated amplifier, connected to my computer via a Halide DAC HD, and to an Oppo CD player. That system had pitch-perfect tone and was satisfying with all types of music.
The Pass Labs integrated elicited a pristine, extremely well-sorted behavior from the O/93s. It played Wagner's Die Walküre, with Birgit Nilsson and Gré Brouwenstijn singing and Erich Leinsdorf conducting the London Symphony Orchestra (44.1/16 FLAC, Decca/Tidal), with an unprecedented amount of detail and spatial acuity. Better still, the INT-25 allowed the O/93s to play this utterly stunning Kenneth Wilkinson recording at highish volumes—with no noticeable clipping. No blurring. No clumping of detail. And no solid-state hardness.
Please forgive my focus on opera recordings. Probably…
Sidebar 1: Specifications
Description: Stereo integrated amplifier operating in class-A using JFETs and MOSFETs. Inputs: 3 pairs single-ended (RCA). Outputs: stereo pair of Furutech 3-way binding posts. Power output: 25Wpc into 8 ohms (14dBW), 50Wpc into 4 ohms (14dBW). Peak current: 10A (200W peak into 2 ohms). Class-A envelope: 50W peak for 2, 4, or 8 ohm load. Bandwidth: DC to –2dB at 100kHz. Input impedance: 47k ohms. Voltage gain: 26dB. Damping factor: 500. Slew rate: 100V/µs. Idle power draw: 2.3 amps at 120VAC (240W).
Dimensions: 17" (430mm) W × 6" (150mm) H × 17.9" (454mm) D…
Sidebar 2: Associated Equipment
Analog sources: Dr. Feickert Analogue Blackbird turntable with Jelco TK-850L tonearm and Koetsu Rosewood Signature Platinum moving-coil cartridge; AMG Giro G9 turntable with 9W tonearm and Etsuro Urushi Cobalt Blue moving-coil cartridge.
Digital sources: Apple Mac mini computer running Audirvana Plus; HoloAudio Spring "Kitsuné Tuned Edition" Level 3 D/A processor; Integra DPS 7.2 (used as CD transport).
Preamplification: EMIA MC step-up transformer (with Koetsu), Excel Sound Corporation ET-U50 SUT (with Etsuro Urushi); Musical Surroundings…
Sidebar 3: Measurements
Prior to measuring the Pass Labs INT-25 using my Audio Precision SYS2722 system, I preconditioned it for an hour at one-third power into 8 ohms. At the end of that time, the heatsinks on the amplifier's sides were hot, at 122°F (50°C), as was the top panel, at 116.6°F (47.8°C). Owners should make sure this amplifier is well-ventilated. The amplifier's maximum voltage gain into 8 ohms was 25.4dB, and the amplifier preserved absolute polarity (ie, was noninverting).
The Pass Labs' input impedance is specified as 47k ohms; I measured 46k ohms at 20Hz and 1kHz…
On a snowy day in March 2019, the first room I visited at the Montreal Audio Fest, hosted by retailer Audio by Mark Jones, featured the world premiere of the Magico M2 loudspeaker. The soundstaging produced by these elegant towers was palpable, the full-range tonal balance superbly uncolored. Both aspects reminded me of my experience of Magico's S5 Mk.II loudspeaker, which I enthusiastically reviewed in Stereophile's February 2017 issue. Accordingly, I made a note that the M2 was going on my "must review" list. Seven months later, Magico's Alon Wolf and Peter Mackay visited to set up a pair…
"You do not want to put the speaker directly on softer-material dampers because they will allow it to move. So how do you couple it below a certain frequency, yet let it float above a certain frequency? That's how we came up with the MPods. We use constrained-layer damping to very effectively dissipate high-frequency vibration as heat. Below 300Hz, the speaker sees just a direct contact, there's no dissipation of any energy. But above that frequency, the constrained-layer damping dissipates the noise."
Setup
After making sure the M2s' tension rods were correctly torqued, Wolf and…
Sidebar 1: Specifications
Description: Three-way, sealed-box, floorstanding loudspeaker. Drive-units: 1.1" (28mm) diamond-coated beryllium-dome tweeter, 6" (153mm) XG Nanographene–cone midrange unit, two 7" (178mm) XG Nanographene–cone woofers. Crossover frequencies: not specified. Frequency range: 26Hz–50kHz. Nominal impedance: 4 ohms. Sensitivity: 88dB/W/m. Minimum recommended power: 50W.
Dimensions: 45" (1143mm) H × 18" (457mm) W × 17.5" (445mm) D (all with MPod three-point stand). Weight: 165lb (75kg) each (with MPod stand).
Finish: Matte black aluminum baffle, top, and base…
Sidebar 2: Associated Equipment
Analog source: Linn Sondek LP12 turntable with Lingo power supply, Linn Ekos tonearm, Linn Arkiv B cartridge, Channel D Seta L phono preamplifier.
Digital sources: Roon Nucleus+ file server; Ayre Acoustics C-5xeMP universal player; PS Audio PerfectWave DirectStream and Chord Electronics DAVE D/A processors, Chord Hugo M Scaler upsampler, Ayre QA-9 A/D converter.
Power amplifiers: Lamm Industries M1.2 Reference (monoblocks).
Integrated amplifier: NAD M10.
Cables: Digital: AudioQuest Vodka (Ethernet), AudioQuest Coffee (USB), DH Labs (1m, AES…
Accessory of 1997
HeadRoom Max headphone amplifier ($1335; reviewed by Wes Phillips, Vol.20 No.2, February 1997 Review)
Finalists (in alphabetical order):
AudioPrism CD Blacklight ($39.95; reviewed by Sam Tellig, Vol.19 No.11, November 1996)
AudioQuest Binding-Post Wrench ($7.95; reviewed by Wes Phillips, Vol.20 No.9, September 1997)
Bright Star Air Mass 3 ($99; reviewed as the Air Mass 1 by Michael Fremer, Vol.20 No.2, February 1997)
Bright Star Ultimate TNT Suspension System ($893; reviewed by Wes Phillips, Vol.20 No.7, July 1997)
Grado Reference Series RS1…