Digital sources: Roon Nucleus+ music server; Astell&Kern AK100 portable player; MBL N31 CD player/DAC; PS Audio DirectStream D/A processor; Ayre Acoustics QA-9 A/D converter.
Preamplifiers: MBL Noble Line N11, Pass Labs XP-32.
Power amplifiers: Parasound Halo JC 1+ monoblocks.
Loudspeakers: KEF LS50, Sonus Faber Lumina III.
Cables: Digital: AudioQuest Vodka (Ethernet, TosLink), Canare 110 ohm (AES/EBU, 15', auditioning, and 45', measuring). Interconnect: AudioQuest Wild Blue (balanced). Speaker: AudioQuest K2. AC: AudioQuest Dragon…
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Sidebar 2: Associated Equipment
Sidebar 3: Measurements
I examined the amount of timing uncertainty—jitter—in the Grimm Audio MU1's AES/EBU output using my Audio Precision SYS2722 system's digital oscilloscope function. I overlaid successive snapshots of the MU1's AES/EBU output, taken over a 60-second time window, to show what's called an "eye pattern." To make things as difficult as possible for the MU1, the AES/EBU link was a 45' length of Canare 110 ohm balanced interconnect and the data represented the 24-bit Miller-Dunn J-Test signal sampled at 44.1kHz. With an ideal transmission system, all the pulse transitions…
I am not a fan of that amp designer who promoted his products by pointing a condescending finger while scolding audiophiles, like errant children, for preferring their records to sound "pleasant" rather than "accurate."
He reminds me of my least favorite teacher, Professor Grausamkeit, who was just like that and said similar things. Every time I smarted back, "Accurate to what?" he'd whack me with a wooden yardstick.
Grausamkeit would twist my ear painfully while scolding me but would never explain what "accurate" sounded like or why it didn't sound pleasant. Best I could figure…
Be aware: When choosing speakers for use with low-power tube amps, the sensitivity spec is less important than finding a speaker with a flat, high, nonreactive impedance characteristic.
The Soul Supremes satisfy this requirement by using a crossover with only a voltage divider (two resistors), and a single capacitor to attenuate the 113dB/W/m–sensitive Radian ribbon tweeter at 12kHz. The Zu's doped-paper cone mid/woofer handles the other octaves wide open, with no crossover or response modeling. The tradeoff is, running full-range, the Zu's 10.3" cone makes a bit of jitter-like breakup…
On top of a desk, an audio system must be able to deliver satisfying sound in a nonoptimal environment: a flat, reflective plane (the desktop) cluttered with keyboard (or maybe a laptop computer); a mouse; assorted papers, books, and trash; and, perpendicular to that, another flat, reflective plane (the computer display), which, if it's not a tiny laptop screen, will block some of the soundwaves emanating from the speakers. Such sonically inhospitable spaces can consign 3D stereo imaging (and other desirable sonic traits) to the realm of the imagination.
My workspace is especially…
The four digital inputs (USB, Walkman, optical, and stereo mini) are on the "A" speaker's left side. A's rear panel offers pairs of unbalanced (RCA) and balanced (XLR) analog inputs and a left/right switch, which determines whether speaker A or speaker B receives the right (or left) signal. Here, also, are the aforementioned digital sync cable and the power inlet.
Speaker B's front panel holds four acoustic adjustment knobs. Addressed from left to right, the D.A. ASSIST (D.A. Hybrid amplifier analog assist) allows you to choose whether to use the analog amplifier only for error-…
Sidebar 1: Specifications
Description: Nearfield active speaker system for desktop listening. Drive-units: ¾" (19mm) titanium-sputtered soft-dome tweeter, two 9/16" (14mm) titanium-sputtered soft-dome tweeters; two 4" (100mm) anodized-aluminum–cone woofers. Crossover frequencies: 5kHz, below 200Hz (adjustable, for assist woofer integration). Inputs, digital: USB-B, Walkman/Xperia, TosLink. Inputs, analog: XLR, RCA, Stereo Mini. Total amplifier power: 106W. THD: 0.03% (1kHz, 10W). Frequency range: 10Hz–200kHz. S/N ratio (A-weighted): 100dB. Power consumption, active: Speaker A, 60W,…
Sidebar 2: Associated Equipment
Digital sources: Apple 27" iMac, 2017 model with 3.8GHz Intel Core i5 processor and 16GB RAM; Apple 15" MacBook Pro, 2017 model with 2.8 GHz Quad-Core Intel Core i7 processor and 16GB RAM; both running Roon 1.7 (build 667). Mytek Manhattan II D/A Converter; Arris SB8200 modem and Linksys MR8300 v 1.1 mesh router with HDPlex 200 linear power supply.
Loudspeakers/Amplification: Dragonfire Acoustics Mini Dragon DFA 2.1 desktop playback system with Mini Dragon Satellites (2), SB-8P subwoofer, MD-4 amplifier, and SHD. Dynaudio Focus 200XD wireless active…
Sidebar 3: Measurements
I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the loudspeaker's frequency response in the farfield and an Earthworks QTC-40 mike for the nearfield responses, using the Sony SA-Z1's single-ended analog inputs. I also used the Earthworks microphone to measure the Sony speaker's farfield responses with the TosLink digital input.
Looking first at the digital inputs, the TosLink optical input accepted S/PDIF data sampled at rates up to 96kHz. The USB port operated in the optimal isochronous asynchronous mode, and Apple's USB…
UPDATE: This webinar is now available for replay!
Replay Sonus faber Webinar LIVE: Friday, March 5, 2021 - 12:00PM ET
Join us when Sonus faber will present a brief journey through the history, philosophy, and technology of their company and how these apply to their latest products. Featuring the new Lumina family of passive loudspeakers, Palladio architectural series, and Gravis Subwoofers.
On hand to present the products and answer your questions during the live webinar:
William Kline: Sonus faber North American Brand Manager
Paolo Tezzon: Sonus…