Description: Two-channel, tubed power amplifier with unbalanced and balanced input jacks. Tube Compliment: (3) 12AX7, (4)12AT7, (4) KT-88/6550. Rated output power: 75Wpc into 4/8/16 ohms, 20Hz–20kHz. S/N ratio: 100dB A-weighted. Frequency Response: 20Hz–20kHz, +0/–0.5dB, 10Hz–70kHz, +0/–3dB. Sensitivity: 1.2V unbalanced, 2.5V balanced. Maximum THD from 250mW to rated power: 0.5%. Maximum Intermodulation Distortion if instantaneous peak output per channel does not exceed twice the rated output, for any combination of frequencies, 20Hz–20kHz, with both channels…
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"This won't be a short job," says Arcam's president, John Dawson (footnote 1). He's talking about the challenge of engineering the next generation of Arcam home-theater products to embrace the new high-resolution video formats. It's possibly the biggest technical challenge English company Arcam has faced since, almost exactly 30 years ago, Dawson and his original business partner, Chris Evans, launched their first product—an unpretentious, 35W hi-fi amplifier called the A&R Cambridge A60.
It was Dawson's own personal combination of technical know-how and commercial enthusiasm that…
There are bound to be issues in how BD+ and AACS, which is supposed to stand independently, interact with each other. There is much FUD (fear, uncertainty, and doubt) and misinformation going around about this at the moment, and this will become clear only when everything is finally published in at least some sort of public domain. It's potentially a big can of worms.
Is the system needlessly complicated? I suspect it is! I saw a lovely piece on one of the websites the other day which said, "For God's sake, with all this interactivity, and getting the director's comments in multiple…
Here's something that's difficult to visualize but nonetheless true: If you attempt to isolate from their environment the working bits of a record player—the main bearing, platter, tonearm, and cartridge—by means of an elastic drive belt and a suspended subchassis of the usual sort, you'll create almost as many problems as you solve.
If your suspension system is designed correctly, then the fragile relationship between cartridge stylus and record groove will be less vulnerable to certain kinds of interference; additionally, the soft drive belt may indeed filter out some of the noise…
Back into the setup jig went the cherry LP12. I stripped it to the plinth once again, then removed the platter bearing from the stock Linn subchassis. (No, I couldn't find the red rubber cap meant to seal the bearing well; yes, I spilled some of the oil; yes, I was wearing off-white trousers at the time. Much hilarity ensued.) The Vector Link kit came with a nice set of machined aluminum rings that are adaptable to either Linn's Cirkus or pre-Cirkus bearings, and are intended to safely and evenly distribute the torque of the mounting bolts. The remarkably light subchassis combines a balsa…
Older audiophiles remember the splash NAD made in the late 1970s with the introduction of their 3020 integrated amplifier ($175). Ridiculously cheap, it looked graceful and sounded warm, inviting, and holographic. Removable jumpers between the 3020's sections permitted enthusiasts to determine whether the magic resided in its preamp, its power amp, or in some synergy of both.
In the opinion of most listeners, it was both. But while the 3020's relatively low-powered amplifier (conservatively rated at 20Wpc into 8 ohms) limited it to driving small, efficient loudspeakers, its…
NAD's PowerDrive circuit continually monitors output current and adjusts the power-supply voltage rails to maximize the dynamic power sent to the speakers. According to NAD, PowerDrive makes the M3 sound far more powerful than its rated 180Wpc. (For a detailed explanation of PowerDrive, see the sidebar "What Is PowerDrive?," in Jim Austin's review of NAD's C 372 integrated amplifier in the October 2006 Stereophile.)
The power-amp circuit uses a wideband, current-mode, class-A voltage amplifier and an NAD-patented current-amp output stage with small amounts of feedback to help deliver…
Sidebar 1: Specifications
Description: Solid-state, two-channel, remote-controlled integrated amplifier with seven line inputs (including one balanced XLR). Rated maximum output power at clipping: 220W (23.4dBW). Continuous average output power: 180Wpc into 4 or 8 ohms (22.5dBW) within rated distortion. Dynamic power: 300Wpc (24.7dBW) into 8 ohms, 520W (27.2dBW) into 4 ohms, 700W (28.4dBW) into 2 ohms. Frequency response: 20Hz–20kHz, ±0.3dB (–3dB at >80kHz). Damping factor, ref. 8 ohms, 50Hz: >150. Amplifier input impedance (R, C): 20k ohms, 680pF. Input sensitivity, ref. rated…
Sidebar 2: Associated Equipment
Analog Sources: Continuum Audio Labs Caliburn, Kuzma Reference XL, Metronome Gaia turntables; Graham Phantom, Continuum Cobra, Kuzma Airline tonearms; Lyra Titan (stereo, mono), Lyra Skala, Transfiguration Orpheus cartridges.
Digital Sources: Naim CD555 CD player; Alesis Masterlink BPT-modified, hard-disk–based recorder.
Preamplification: Manley Steelhead, ASR Basis Exclusive phono preamplifiers; Musical Fidelity kWP preamplifier.
Power Amplifiers: Musical Fidelity kW monoblocks.
Loudspeakers: Wilson Audio Specialties MAXX2, Peak Consult El…
Sidebar 3: Measurements
As usual, I preconditioned the NAD M3 by running it at one-third its specified power into 8 ohms for one hour with both channels driven. While the measured percentage of THD+noise remained constant throughout this period, at a low 0.0035%, the chassis got almost too hot to touch, and the side-mounted heatsinks definitely so. Measured at its speaker terminals, the M3 offered a maximum voltage gain of 39.2dB into 8 ohms for both balanced and unbalanced input signals. With the volume control set to "0.0dB," the overall voltage gain was 29.2dB. This was also the gain…