Description: Solid-state stereo preamplifier with remote control & headphone amplifier. Inputs: 4 single-ended (RCA), 1 single-ended Record (RCA), 2 balanced (XLR). Input impedance: 6.5k ohms (RCA), 4.5k ohms (XLR, inverting and non-inverting). Outputs: 1 single-ended variable (RCA), 1 single-ended fixed (RCA), 2 pairs balanced (XLR), 1 headphone (1/4", 6.35mm TRS). Control connectors: female DB9 for full two-way RS-232 (RJ12) suite; two 3.5mm mono (TS) miniplug DC triggers (12V); one auxiliary IR input with external IR receiver terminated with 3.5mm plug.…
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Sidebar 2: Associated Equipment
Analog Sources: Linn Sondek LP12 turntable with Lingo power supply, Linn Ittok tonearm, Spectral MC cartridge; Day-Sequerra 25th Anniversary FM Reference, McIntosh Laboratory MR-78, Sony XDR-F2HD FM/AM tuners.
Digital Sources: Bryston BCD-1 CD player & BDP-3 media player (IAD soundboard) & BDA-3 DAC; Oppo digital BPD-103 universal BD player; Lenovo P50 ThinkPad computer running Windows 10 Pro (64-bit), Bryston Windows USB driver, JRiver Media Center 23, Roon Core V.1.4 (build 300).
Preamplification: Sutherland Engineering KC Vibe phono…
Sidebar 3: Measurements
I measured the Bryston BP-173's performance with my Audio Precision SYS2722 system (see the January 2008 "As We See It"). The maximum gain for both the balanced and unbalanced inputs to the balanced outputs, and from the headphone output, was 17.5dB. The maximum gain from unbalanced input to unbalanced output was 11.6dB; ie, an input of 1V results in an output of 3.785V.
The BP-173's input impedance from 20Hz to 20kHz was 6800 ohms unbalanced and 10k ohms balanced, both impedances very slightly higher than specified. The preamplifier preserved absolute…
The Kii Three speaker on top of its BXT woofer module.
For years, I have had the Munich High-End Show on my bucket list and, this year was the time to cross it off. Past reports have been enticing not only from the detailed reports of a wealth of familiar, not-so-familiar and some downright unknown audio companies but, even more, because it is said to be the best show in terms of venue, focus and community spirit.
I landed in Munich on Thursday morning, dumped my luggage at a downtown hotel and hopped on the U-bahn to the M.O.C. out in the quiet suburb of Freimann. Physically,…
At age 62, pianist Fred Hersch is playing as rousingly and rivetingly as ever. His latest disc, Live in Europe (on the Palmetto label), may be his best trio album to date.
It also highlights another, less-noted trait—his restlessness. Hersch's sound is familiarly distinctive, but he never falls back on old tricks. He is known for his lush harmonies and galvanic rhythms. He'll occasionally toss a discordant number into a set, but it often comes off as an excursion. Here, though, he weaves the lyrical and the adventurous into a seamless web. His touch is, at times, both fleet and percussive…
At the 2018 Consumer Electronics Show, when John Atkinson and I entered the room shared by Lamm Industries, Aqua Acoustic Quality, and Kharma room, we were looking for two things: good sound, and digital products for me to review. When we spied AAQ's Formula xHD digital-to-analog converter, the possibility of evaluating a potentially excellent DAC made by someone other than the usual suspects felt like a golden opportunity.
There were two mitigating factors. First, I usually don't use a preamplifier with either of my reference DACs, dCS's Rossini ($23,999) and Vivaldi ($35,999). Instead…
Three days and three pages of extremely detailed notes later, after the Formula xHD had passed the 400-hour mark, its top began to open up, revealing a sound suffused with light and a beautiful, warm midrange. Burning it in further while reviewing soprano Sonya Yoncheva's The Verdi Album, with Massimo Zanetti conducting the Munich Radio Orchestra (CD, Sony Music 0889854179823; 24/96, Primephonic), I finally noticed the emergence of a three-dimensional soundstage, and the Formula xHD's ability to reveal the changing colors and weights of voice and orchestra as emotions shifted—as well as…
Sidebar 1: Specifications
Description: D/A processor with proprietary Optologic D/A conversion system. Pure R2R ladder: FPGA-based without digital filter. Compatible formats: PCM to 16–24-bit/44.1–768kHz, DSD64–DSD256 via DoP, DXD. Digital inputs: RJ45 AQlink (I2S serial bus), BNC coax (S/PDIF, 75 ohm), RCA coax (S/PDIF), AES/EBU (balanced, 110 ohm), USB 2 Type 2.0 (OSX, Linux driverless, all formats). Modular input: AES/EBU, RCA coax, AT&T (ST Fiber), Optical TosLink. Analog outputs: 1 pair unbalanced (RCA); 1 pair transformer-coupled balanced. Maximum output level: 2.4V, unbalanced…
Sidebar 2: Associated Equipment
Digital Sources: dCS Paganini SACD/CD transport & Scarlatti clock & Rossini DAC & Vivaldi DAC & Network Bridge network player; Oppo Digital UDP-205 universal BD player; Intel NUC7i7BNH with 8GB RAM, 128GB SSD running Roon; Linksys router with 2 TP-Link gigabit Ethernet media converters & multimode duplex fiber-optic cable; Apple MacBook Pro computer with Intel i7, SSD, 8GB RAM; iPad Pro; external hard drives, USB sticks.
Preamplifier: Lamm Industries L2.1 Reference.
Power Amplifiers: Dan D'Agostino Master Systems Progression,…
Sidebar 3: Measurements
I measured the Aqua Formula xHD DAC with my Audio Precision SYS2722 system (see the January 2008 As We See It"), using both the Audio Precision's coaxial and AES/EBU digital outputs, and USB data sourced from my MacBook Pro running on battery power with Pure Music 3.0 playing WAV and AIFF test-tone files. Apple's USB Prober utility identified the Formula xHD as "aqua XHD" from "aqua," its serial number as "0 (none)," and confirmed that its USB port operated in the optimal isochronous asynchronous mode. Apple's AudioMIDI utility revealed that, via USB, the Formula…