Description: USB DAC/headphone amplifier. Input: USB Micro B 2.0 port. Output: 3.5mm headphone jack. Resolution/sample rates: 24 bits/192kHz. DAC chip: eight-channel ESS (4 DACs per channel). THD+N: –107dB, 600 ohm load at 16dBu; –100dB, 30 ohm load at 10.5dBu. Dynamic range: 117dB (A-weighted). Frequency response: 10Hz–20kHz, ±0.2dB. Maximum output: 225mW into 30 ohms, 40mW into 600 ohms. Power: 5V, 500mA via USB 2.0 bus.
Dimensions: 3.7" (95mm) L by 1.2" (30mm) W by 0.6" (16mm) D. Weight: 1¾ oz (45.35gm).
Serial number of unit reviewed: G1E100151900145…
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Sidebar 1: Specifications
Except as noted, I drove the Paradigms full-range with two-channel recordings, using an Integra DTC-9.8 surround processor strictly as a 2.0-channel digital preamplifier in its Direct mode. I later briefly tried a Jeff Rowland Design Group Consummate analog preamp, but the system's sound jelled better with the Integra. The amplifier was a Proceed AMP5, though for this review I used only two of its five channels. Each channel of the AMP5 is driven by a completely separate power supply and transformer, in effect making it, for this review, two monoblocks built on the same chassis. The source…
Sidebar 2: Associated Equipment
Digital Sources: Apple MacBook Pro computer (2.66GHz Intel Core 2 Duo, 8GB RAM, 512GB SSD) running OS 10.11, Amarra Computer Music Player, iTunes 12, JRiver Media Center 19, Reaper 4.78, Roon v.1.1 Build 65, VLC, XLD; Western Digital NAS Device (2TB); Oppo BDP-103 universal BD player; Meridian Sooloos Digital Media System (Control 15, QNAP TS-669 Pro NAS); Apple iPad Air, iPod Touch 1G, iPhone 6.
Digital Processors: AudioQuest JitterBug, Audioengine D3, AudioQuest DragonFly USB DAC, Aurender AUR-V1000 Flow, Cambridge Audio DacMagic XS, Chord Hugo TT,…
Sidebar 1: Specifications
Description: Floorstanding, 2.5-way, bass-reflex loudspeaker with two rear ports. Drive-units (all X-PAL): 1" dome tweeter, 8" mid/woofer, two 8" woofers. Crossover frequencies: 400Hz, 2kHz. Crossover: 2.5-way, second-order electroacoustic. Frequency response: 37Hz–20kHz, ±2dB (on axis); 37Hz–17kHz, ±2dB (30° off axis). Sensitivity (anechoic): 91dB. Impedance: compatible with 8 ohms. Recommended amplification: 15–450W.
Dimensions: 44.4" (1138mm) H by 13.2" (338mm) W by 17" (435mm) D. Weight: 99 lbs (45kg).
Finishes: Piano Black, Walnut, Black Walnut,…
Sidebar 3: Measurements
I measured the Apogee Groove with my Audio Precision SYS2722 system (see www.ap.com and the January 2008 As We See It"). The source was USB from my 2012 MacBook Pro running on battery power. Macintosh's USB Prober utility reported the Groove's product string as "Groove" from "Apogee," and confirmed that its USB port operated in the optimal isochronous asynchronous mode. Apple's AudioMIDI utility confirmed that the Groove operated at all sample rates from 44.1 through 192kHz with 24-bit integer data.
The Groove preserved absolute polarity (ie, was non-…
Sidebar 2: Associated Equipment
Digital Sources: Marantz UD7007, Oppo BDP-105D universal BD players.
Preamplification: Integra DTC-9.8 preamplifier-processor, Jeff Rowland Design Group Consummate preamplifier.
Power Amplifier: Proceed AMP5.
Loudspeakers: Energy Veritas v2.8.
Cables: Interconnect: Kimber Kable AGDL (digital coax, sources to Integra), AudioQuest Niagara (analog to Consummate), Cardas Hexlink (preamps to power amp), generic HDMI (Oppo to Integra). Speaker: Monster Cable M1.5.—Thomas J. Norton
Sidebar 3: Measurements
I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Paradigm Prestige 95F's frequency response in the farfield; for the nearfield frequency response, I used an Earthworks QTC-40, which has a ¼" capsule and thus doesn't present a significant obstacle to the sound.
The Prestige 95F's voltage sensitivity is specified as 91dB/2.83V/m anechoic and 94dB in-room. My estimate was very close to this, at 92dB(B)/2.83V/m. This is a speaker that plays loudly with very few watts. The 95F's impedance is specified as being "compatible with 8…
Bryston BDP-2 digital media player, from October 2013 (Vol.36 No.10)
I was surprised when Bryston, manufacturers of the BDP-1 digital player ($2195), released a new version, the BDP-2 ($2995), a scant 21 months after I'd reviewed the BDP-1 in the June 2011 Stereophile. This jolted me—I'd purchased the review sample of the BDP-1 to use as my reference source for playing high-resolution digital files. Having my new reference player superseded less than two years after its purchase reminded me how fast computers become obsolete, compared to audiophile amplifiers and preamplifiers.
…
Convergent Audio Technology SL1 Renaissance Black Path Edition preamplifier, from December 2015 (Vol.38 No.12)
Known simply as "the CAT," Convergent Audio Technology's SL1 tubed preamplifier first appeared in 1985, and ever since has been the subject of almost continuous improvement (footnote 1). According to Ken Stevens, founder and chief designer of Convergent Audio Technology, some of those improvements—use of a specific wire, tweaking the value of a certain resistor, a minor change in wiring layout, etc.—used to be incorporated into production with no change in model name, and with…
Sidebar: CAT's Capacitor Shoot-outs
A capacitor shoot-out is a method for selecting capacitors that have the potential to produce the best sound. It does not involve measurements—Convergent Audio Technology's Ken Stevens has found that measurements of capacitors taken with even the most advanced laboratory instruments reveal very low correlation with sound quality. On the other hand, such factors as termination technique, film tension, core construction, and wrap style—all of which have virtually no effect on traditional capacitor measurements—may profoundly affect the sound. The only way…