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At the top of the Di150 LE's rear panel are two pairs of WBT speaker binding posts. Below those are, from left to right: pairs of unbalanced outputs marked Tape Out and Out; balanced right and left outputs marked R Out and L Out; that tiny HTH toggle; unbalanced HTH, Tape, Tuner, and CD inputs; and two sets of right and left balanced inputs, labeled Bal 1 and Bal 2. In the lower left corner is the IEC mains plug. All balanced outs and ins are XLR plugs and sockets, respectively; unbalanced connections are Neutrik-made RCAs. And each side panel of the Di150 LE is actually a massive heatsink…
Sidebar 1: Specifications
Description: Solid-state, class-AB, integrated amplifier. Analog inputs: 2 balanced (XLR), 4 unbalanced (RCA). Amplifier outputs: 1 balanced (XLR), 1 unbalanced (RCA), 1 tape (RCA), 1 speaker. Power output: 180Wpc into 8 ohms (22.55dBW), 360Wpc into 4 ohms (22.55dBW, 700Wpc into 2 ohms (22.4dBW). Frequency response: 10Hz–50kHz, ±0.1dB. Distortion: 1kHz, >0.05% (mainly second harmonic). Signal/noise: >100dB, A-weighted. Input impedance: 20k ohms unbalanced, 40k ohms balanced. Line output impedance: 75 ohms unbalanced, 150 ohms balanced. Power consumption:…
Sidebar 2: Associated Equipment
Analog Sources: Kuzma Stabi S turntable & Stogi tonearm; Music Hall MMF-7.3 turntable; Goldring Elite MC, Ortofon 2M Bronze cartridges.
Digital Sources: Apple MacBook computer running Audirvana Plus; Halide DAC HD, PS Audio NuWave DACs; Western Digital T2 Mirror Drives (2), LG BD550 Blu-ray player (as transport).
Preamplification: Auditorium 23 A23 moving-coil step-up transformer, Heed Audio Quasar phono stage, Shindo Laboratory Allegro preamplifier.
Power Amplifier: Shindo Laboratory Haut-Brion.
Integrated Amplifier: Heed Audio Elixir…
Sidebar 3: Measurements
I performed a full set of measurements on the GamuT Di150 LE using my Audio Precision SYS2722 system (see the January 2008 "As We See It"). I preconditioned the amplifier by running it with both channels driven at one-third power into 8 ohms for 60 minutes. This is, thermally, the worst situation for an amplifier with a class-B or -AB output stage, as one-third power is when the output transistors dissipate the most heat. At the end of the hour, the side-mounted heatsinks were very hot, with a temperature of 135°F (57.3°C), and the temperature of the top panel was…
When it comes to Focal loudspeakers, I've been a lurker. For decades now, their demonstrations at audio shows have been memorable—a highlight was when, several years ago, I got Focal to play a powerful percussion track through a pair of their Grande Utopias at very high volume on a show's last day. Just to hear and feel how this mammoth system could deliver clarity and impact was awe-inspiring, and it was underscored by seeing folks from all the neighboring rooms quickly entering to enjoy it with me. It has also been a continuing pleasure to relax and listen to music with Stereophile's…
The bass was also better controlled—or was I just adapting to it? Now I took Hurry's advice about the spikes. The Sopra No.3's stainless-steel spikes come pre-installed in the speaker's base of tempered glass—all I had to do was turn the knob at the top of each threaded spike until it protruded through the rubber feet. To protect my floors, I borrowed some of the nice magnetic spike cups from my Bowers & Wilkins 802 D3 loudspeakers that were now lying around unused. I adjusted the spikes with reference to a small bubble level placed on each Sopra's base. It worked: The lowest…
Sidebar 1: Specifications
Description: Three-way bass-reflex floorstanding loudspeaker. Drive-units: 1.125" (27mm) pure beryllium inverted-dome tweeter, 6.5" (165mm) W-cone midrange driver, two 8.25" (210mm) W-cone woofers. Crossover frequencies: 250Hz, 2.2kHz. Frequency response: 33Hz–40kHz, ±3dB. Sensitivity: 91.5dB/2.83V/m. Nominal impedance: 8 ohms. Minimum impedance: 3.1 ohms. Recommended amplification: 40–400W.
Dimensions: 49.8" (1264mm) H by 15.8" (402mm) W by 23.4" (595mm) D. Weight: 154.3 lbs (70kg).
Finishes: Carrara White, Black Lacquer, Imperial Red, Electric Orange,…
Sidebar 2: Associated Equipment
Digital Sources: Oppo Digital BDP-105 universal BD player, Baetis XR3 PC-based music server, exaSound e28 Mk.II DAC, QNAP TS569L NAS.
Preamplifiers: Audio Research MP1, Parasound Halo P 7.
Power Amplifiers: ATi AT543nc, Classé Sigma Mono monoblocks, Monoprice Monolith 3, Parasound Halo A 31.
Loudspeakers: Bowers & Wilkins 802 D3, JL Audio E110 subwoofer.
Cables: Analog Interconnect: AudioQuest Earth/DBS balanced. Digital Interconnect: AudioQuest Vodka (HDMI) & Carbon (USB). Speaker: AudioQuest Granite. AC: AudioQuest NRG-10, JPS…
Sidebar 3: Measurements
I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Focal Sopra No.3's frequency response in the farfield, and an Earthworks QTC-40 for the nearfield responses. (I measured serial number '000325.)
The Focal will play loudly when fed only a few watts, my estimate of its voltage sensitivity being 89.2dB/2.83V/m. However, as fig.1 shows, the Sopra No.3 is a difficult load for an amplifier to drive, with a minimum magnitude of 2.75 ohms at 96Hz and a combination of 4 ohms and a –56° electrical phase angle at 68Hz, both frequencies…
I was pumped about this year's Montreal Audio Fest, the city's 30th consecutive audio show, for a couple of reasons. First, I was pumped because I was covering the show for Stereophile with the estimable Art Dudley, and, second, because after last year's debacle that saw the show being unceremoniously cancelled by then-fest organizers/owners, the Chester Group, then resurrected by previous and self-re-instated show organisers, Michel Plante and Sarah Tremblay, the event's rapid revival was proof to me that the Montreal audio show still has legs and a purpose.
Stepping off the 10th floor…