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I was cheerfully surprised by how similar the First Watt J2 and Line Magnetic LM-518IA sounded driving the Soul Supremes. Both delivered an easy-flowing, articulate musicality that let me relax and slip into the music. Both did rhythm and momentum as well as the best amplifiers I know. Both demonstrated extraordinary tonal character. Both danced wildly and jammed into the mosh pits. Both did candlelit seduction. The biggest difference I could feel was not in how each amp sounded or played music, but in how each had its own special way of controlling the speakers and establishing the music's…
When Pass Labs is mentioned, it's natural to think of its founder, iconic engineer Nelson Pass. But Nelson heads a team of engineers at the California company: Their XP-30 preamplifier, which I enthusiastically reviewed in April 2013, was designed by Wayne Colburn; and the subject of this review, the HPA-1 headphone amplifier, is the first Pass Labs product designed by Jam Somasundram, former director of engineering for Cary Audio. Somasundram joined Pass Labs in July 2013; he spent a year working on the HPA-1, which was shown at the 2015 Consumer Electronics Show, in Las Vegas, but not…
Sidebar 1: Specifications
Description: Two-way loudspeaker with "Zu-Griewe" acoustic woofer loading. Drive-units: Radian 850 compression-driver tweeter with 3" diaphragm and 2" throat (12–20kHz); Zu103ND/G1-16 10.3" woofer (full-range, unfiltered). Frequency response: 35Hz–20kHz, ±3dB. Sensitivity: 97dB/2.83V/m. Nominal impedance: 16 ohms.
Dimensions: 37.7" (965mm) H by 12" (308mm) W by 12" (308mm) D. Weight: 70.4 lbs (32kg).
Finishes: Ghost Black Maple, Sangria Maple, Blond Maple, American Walnut, Gloss (most colors).
Serial numbers of units reviewed: 0220 Mk.1 (Rev.A1).…
Sidebar 1: Specifications
Description: Solid-state headphone amplifier/line preamplifier. Analog inputs: 2 unbalanced (RCA). Analog outputs: 1 pair unbalanced (RCA), 1 locking ¼" headphone jack. Maximum output power: 3500mW into 20 ohms, 200mW into 300 ohms. Frequency range: 10Hz–100kHz. Voltage gain: 8dB. Input impedance: 50k ohms. Output impedance: <2 ohms, headphones. Signal/noise and channel separation: not specified. THD+N: <0.005% at 1V output. Power consumption: 6W.
Dimensions: 11" (280mm) W by 4.5" (115mm) H by 12.9" (330mm) D. Weight: 14 lbs (6.35kg).
Serial number…
Sidebar 2: Associated Equipment
Analog Sources: Linn Sondek LP12 turntable, SME M2-9 tonearm, Dynavector 20X2L & Hana EL cartridges; Pioneer PLX-1000 turntable, Ortofon 2M Black cartridge.
Digital Sources: Integra DPPS-7.2 DVD-A player, Schiit Audio Bifrost Multibit DAC.
Preamplification: Dynavector SUP-200 step-up transformer; Dynavector P75 Mk.3, Parasound Halo JC 3+ phono stages; PrimaLuna ProLogue Premium, Simaudio Moon Neo 350P preamplifiers.
Power Amplifiers: First Watt J2, PrimaLuna ProLogue Premium, Simaudio Moon Neo 330A.
Integrated Amplifiers: Linear Tube…
Sidebar 2: Associated Equipment
Digital Sources: Antipodes DX Reference, Aurender N10 music servers; Apple 2.7GHz i7 Mac mini computer running OS10.9.4, iTunes 12, Pure Music 3.0, Audirvana Plus 1.5.10; PS Audio PerfectWave DirectStream, Logitech Transporter D/A processors.
Headphone Amplifier: Ayre Acoustics Codex.
Headphones: Audeze LCD-X & LCD-4, AudioQuest NightHawk, Master & Dynamic MH40.
Cables: USB: AudioQuest Coffee. Interconnect (unbalanced): AudioQuest Fire. Headphone: Cardas Clear (balanced), manufacturers' own (unbalanced). AC: manufacturers' own.—John…
Sidebar 3: Measurements
I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Zu Audio Soul Supreme's frequency response in the farfield; for the nearfield frequency responses, I used an Earthworks QTC-40, which has a ¼" capsule and thus doesn't present a significant obstacle to the sound.
My estimate of the Zu Soul Supreme's voltage sensitivity was 91.5dB/2.83V/m, which is lower than the specified 97dB/W/m but still much higher than average. This speaker will play loudly with low-powered amplifiers. In addition, its plot of impedance magnitude and…
Sidebar 3: Measurements
I measured the Pass Labs HPA-1's electrical performance with my Audio Precision SYS2722 system (see the January 2008 "As We See It"). I performed a full set of measurements from both the HPA-1's preamplifier and headphone outputs. The graphs all refer to the headphone output; I comment when the preamplifier output behaved differently.
Both sets of outputs preserved absolute polarity (ie, were non-inverting), and the maximum gain was the same from both, at 8.35dB, this very close to the specified 8dB. The maximum output level at 1kHz was close to 10V. The…
It would only be fair to expect that in the new historic box set, Decca Sound 55 Great Vocal Recitals, there would be a fair number of clunkers amongst the gold. But that is anything but the case. For just a bit more than $2 per CD, you will end up with so many superb performances, recorded by singers in their prime, that unless you already possess almost everything in the box—I do—or you require English translations for most of its contents, purchase is a no-brainer.
Nor are the CDs by any means skimpy in length. The shorter, LP-length recitals that were set down in the analog era are…
The death of famed Memphis producer Lincoln Wayne “Chips” Moman, sent me scurrying off to listen to some Elvis records. Moman was a producer, songwriter, engineer and the man who capped Elvis’ short career revival that followed the 1968 Comeback Special. While he produced “Mama’s Don’t Let Your Babies Grow Up To Be Cowboys,” for Willie Nelson, produced the later Box Tops recordings and wrote or co-wrote a pack of great tunes including “Luckenbach, Texas” (Waylon Jennings), “The Dark End of the Street” (James Carr) and “Do Right Woman, Do Right Man” (Aretha Franklin), it’s the sessions he ran…