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Have you ever dated a girl and then, six months into the relationship, met her superhot younger sister? That pretty much sums up my long-term romance with my old Pass Labs Aleph 3 power amplifier ($2300 when available but long discontinued), and my flirtatious liaison with the übersexy Pass Labs XA30.5 ($5500).

Knowing that I owned an Aleph 3, John Atkinson pimped out an XA30.5 to me so that I might compare the two. I jumped at the chance—I love my Aleph 3 (footnote 1) and wanted to see how Nelson Pass's design…

Description: Solid-state, dual-mono stereo power amplifier. Inputs: 1 pair unbalanced (RCA), 1 pair balanced (XLR). Outputs: 1 pair WBT binding posts. Comms: RS-232 port, 12V trigger input and output. Rated power output: 150W into 8 ohms, 300W into 4 ohms, 600W into 2 ohms (all 21.75dBW). Maximum output voltage: 34V. Maximum output current: 42A peak, 18A continuous. Voltage gain: 31dB. Input impedance: 47.5k ohms. Input sensitivity: 980mV for rated power. Frequency response: 10Hz–200kHz, –3dB. Channel separation: 105dB at 1kHz. Output impedance: 0.01 ohm. Signal…

Digital Sources: Meridian 808i.2 CD player/preamplifier, Ayre C-5xe universal player; Benchmark DAC1, Bel Canto e.One DAC3 D/A converters; Bel Canto USB Link 24/96, dCS 972 digital format converters; Logitech (Slim Devices) Transporter network music player with Apple Mac mini running OSX for media storage.
Preamplifiers: Simaudio Moon Evolution P-7, Parasound Halo JC 2.
Power Amplifiers: Musical Fidelity 750K Supercharger monoblocks, Pass Labs XA30.5.
Loudspeakers: Revel Ultima Salon2.
Cables: Digital: Kimber Illuminations Orchid AES/EBU,…

I used the top-of-the-line Audio Precision SYS2722 system (see the January 2008 "As We See It" and www.ap.com) to assess the Simaudio Moon Evolution W-7's measured behavior; for some tests, I also used my vintage Audio Precision System One Dual Domain.

Before performing any tests on an amplifier, I run it for 60 minutes at one-third its specified power into 8 ohms, which is thermally the worst case for an amplifier with a class-B or -AB output stage. The W-7's heatsinks were around 55°C (131°F) at the end of the period; the THD in the amplifier's outputs…

At the time, there were almost no high-end CD players. Many audiophiles chose Philips/Magnavox models that had been modified by boutique…

Description: Two-channel, oversampling D/A processor with Wolfson WM8740 24-bit DACs and Texas Instruments TMS 320VC5501 digital filter. Digital inputs: S/PDIF coaxial or TosLink optical, USB. Digital input sampling frequencies supported 44.1kHz, 48kHz (32kHz, 88.2kHz, 96kHz, S/PDIF only). Digital outputs: S/PDIF coaxial and TosLink optical. Analog outputs: balanced (XLR), single-ended (RCA). Frequency response: 20Hz to 20kHz ±0.1dB. THD (1kHz, 0dBFS, 24-bit data): <0.001%. S/N Ratio: 112dB. Total correlated jitter: <130ps. Channel separation: >100dB at…

Sam Tellig was so impressed by this $449 D/A processor that he sent me the review sample (which he subsequently bought), so I could examine its measured performance. I used the Audio Precision SYS2722 system (see www.ap.com and "As We See It" in the January 2008 issue), as well as, for some tests, our Audio Precision System One.

The DacMagic's maximum output was 2.1V from its unbalanced RCA jacks, 0.43dB higher than the CD standard's 2V, which will be audible in direct comparisons. The balanced XLR output was exactly twice this voltage, as expected, and…

Editor: Thanks for the very thorough set of metrics testing you gave the Cambridge Audio Azur DacMagic.

Increasingly, today's audiophile demands performance, flexibility, and value. As Sam Tellig described and JA's measurements bore out, the affordable DacMagic is a highly precise yet versatile external D/A converter able to breathe new life into aging CD players and upgrade the audio performance of DVD players, all the while engaging newer entertainment devices such as Internet streamers, and even adding extra intensity to computer games.

At home…