Sidebar 3: Measurements
I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Bowers & Wilkins 705 Signature's frequency response in the farfield, and an Earthworks QTC-40 mike for the nearfield and in-room responses. I measured the impedance with MLSSA, checking the results with Dayton Audio's DATS V2 system. I used the formula in a 1994 JAES paper by Eric Benjamin to calculate with Microsoft Excel what UK writer Keith Howard has called the "equivalent peak dissipation resistance" (EPDR, footnote 1).
Bowers & Wilkins specifies the 705 Signature…
Several audio shows have been canceled or postponed since the COVID-19 pandemic took hold in early 2020: Munich, AXPONA, RMAF, Montreal, and the 2021 Florida Audio Expo, among others. The next scheduled show is the Finest Audio Show, slated for January 9–10 in Zurich. The next one in the Americas is the inaugural Seattle Audio Fest, planned for July 30–August 1. AXPONA, America's biggest show, near Chicago, was recently postponed for the second time until late August. Depending on how the pandemic evolves, it's possible those shows will not be able to take place as planned, either (footnote 1…
"Oh goody!" thought self, to self: "Another Gryphon component to review." As eloquent and revelatory as that statement may be, there's an even more illuminating backstory.
I had been aware of Denmark-based Gryphon Audio since the advent of the Gryphon Exorcist, a now-discontinued demagnetizer that cost far more than your average break-in CD, but I only began to encounter Gryphon electronics at audio shows a few years ago. While at first they seemed available for review only as a complete package, Jim Austin was able to arrange for me to review the Gryphon Ethos CD player–D/A processor ($…
Skov called the 350kHz bandwidth of Gryphon's amplifiers both "enormous" and unusual for amplification with a lot of transistors in parallel. He also said, in passing: "We prefer low-capacitance speaker cables and don't like coaxial speaker cables with or without active shielding. Those cables can be very good for digital amplifiers, reducing glitches and high-frequency noise, but for an analog amplifier with a huge bandwidth, their very high capacitance acts as a filter that limits bandwidth." Happy to say, my Nordost Odin 2 cabling is low capacitance.
Feets, Don't Fail Me Now
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Sidebar 1: Specifications
Description: Solid-state, mono power amplifier. Input: 1 balanced (XLR). Output: 2 pair custom, gold-plated binding posts. Input impedance, balanced (20Hz–20kHz): 10k ohms. Output impedance: 0.0075 ohm. Voltage gain: 31dB. Bandwidth: 0.3Hz–350kHz, –3dB. Input sensitivity: 592mV. Dynamic range: 110dB. THD+N: –110dB. Output power (at 1% THD+N, class-A): 55W into 8 ohms, 110W into 4 ohms, 220W into 2 ohms (all 17.4dBW). Power supply capacity: 440,000µFpc. Power consumption, high bias: <0.5W idle, 350W standby, 1350W maximum.
Dimensions: 18.5" (470mm) W × 9.…
Sidebar 2: Associated Equipment
Digital sources: dCS Rossini SACD/CD transport, Rossini DAC, and Rossini Clock; EMM Labs DV2 Integrated DAC; Synology 5-bay NAS 1019+; Roon Nucleus+ music server with HDPlex 200 linear power supply; Uptone Audio etherRegen, Small Green Computer Sonore opticalModule, TP-Link gigabit Ethernet media converters plus multimode duplex fiberoptic cable (2), Linksys routers (2); Small Green Computer linear power supply & Small Green Computer/ HDPlex four-component, 200W linear power supply (3); external hard drives, SSD USB sticks, iPad Pro; Apple 2017 Macbook…
Sidebar 3: Measurements
I tested the Gryphon Essence with my Audio Precision SYS2722 system (see the January 2008 "As We See It"). I preconditioned the amplifier by operating it with class-AB output-stage bias at one-third the specified power into 8 ohms for an hour. At the end of that time, the top panel's temperature was 88.3°F (31.3°C) and that of the side-mounted heatsinks 90.4°F (32.4°C). Repeating the preconditioning with class-A bias after letting the amplifier cool down resulted in a slightly higher heatsink temperature, 92.1°F (33.4°C). The Essence monoblock easily has…
My, how we've grown! The experience that convinced me of the inevitability of streaming was in 2010 with the tiny, tidy Logitech Squeezebox Touch that, despite being discontinued and disowned by its manufacturer, still has a cult-like following. Since then, we have seen an explosion of devices for file playback from local or nonlocal storage and web streams. They have varied widely in size and price and wildly in their range of capabilities, from do-it-all feature sets with all system audio functions (save speakers) in one box, like the NAD M33, to daisy-chained, specialized components that…
From the Pink Faun via the Okto dac8 PRO, there was no system background noise, and the ambient aura before the music started mapped out a large space. The first notes surprised as they spilled out with requisite hall sound and body resonance from a large instrument that, only milliseconds before, was not there. Anyone who appreciates great piano playing will be hooked for the balance of the recital.
I also listened to one of my John Atkinson–engineered favorites, "The First Tears" by Eriks Eenvalds (The Doors of Heaven, Ethan Sperry, Portland State University Chamber Choir, Naxos 8.…
Sidebar 1: Specifications
Description: Custom, heavily optimized Linux-based digital music streamer/server running Roon core. Tested configuration: Base 2.16x plus USB bridge: $1250; S/PDIF bridge: $1250; Ultralow-noise OCXO clocks for motherboard, USB, and S/PDIF bridge: $1750 each; optional custom Lambo Orange anodized faceplate: $1000. Digital outputs (as equipped): Coaxial S/PDIF, XLR AES/EBU, USB I2S stereo/multichannel. Standard network connection on motherboard including gigabit LAN. Supported file formats: PCM, DSD. Supported sample rates: All PCM formats (limited only by DAC)…
