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AB Sets Up His System For the Last Time Ever (Hopefully)

I spent about sixteen hours last weekend studying a rainbow of frequency anomalies and the subdivisions in which they lie. Why? Because I am an audiophile, and it is fun. Also, it’s my job.

After reading the all-encompassing Audio Glossary at Stereophile.com from front-to-back, I rewrote the glossary as a bulleted list reflecting an organized critical listening process to utilize in the future.

Sections include ‘Midrange: 160—1300Hz,’ ‘Soundstaging and Imaging,’ and the seductive ‘Pleasurable Excess’. In the process, I got to know words I thought I understood a little better,…

Ken From Another Dimension

After each sweepstakes winner confirms receiving their prize, I request a photo of the lucky recipient posing with their reward. Ken Olen’s photo had me mystified. The grainy image of a mustachioed man with a mischievous smile seemed darkened and distant. Where did this picture come from?

Though Olen claims to be from Bedford, New Hampshire, using our fancy photograph-decoding software from partnering magazine Shutterbug and some of John Atkinson's equipment measurement tools, I unveiled Olen’s actual location. He’s in outer space galaxies away! No wonder his transmission came through so…

HRT Music Streamer HD USB D/A processor

No history of the computer-audio marketplace could be complete without some mention of High Resolution Technologies, the California company whose Music Streamer was, in 2009, the first perfectionist-quality USB digital-to-analog converter to sell for as little as $99. One could argue that HRT's entire business model has contributed to shaping our attitudes toward the hobby: Because digital-audio technology continues to evolve at such a rapid pace, HRT has introduced a succession of newer and ever more effective Music Streamers, occasionally to the obsolescence of their predecessors; yet…

HRT Music Streamer HD USB D/A processor Page 2

The very first thing I noticed about the Music Streamer HD's sound was its good sense of scale. I began my serious listening with "Lover, You Should Have Come Over," from Jeff Buckley's Grace (ripped from CD, Columbia CK 57528), and was impressed that the harmonium that opens the song had seemingly doubled in size compared to when I heard it through my reference affordable DAC, the Halide DAC HD. (In fact, my listening notes say "tripled," but passing time has eroded my exceedingly slight tendency to exaggerate.) Yes, the HRT processor had higher apparent output, yet even after I'd…

HRT Music Streamer HD USB D/A processor Specifications

Sidebar 1: Specifications

Description: Single-box, bus-powered digital/analog converter. Digital input jack: USB type B. Analog output jacks: RCA (single-ended), XLR (balanced). Sampling rates accepted: up to 192kHz. Word lengths accepted: 16, 24 bits. Frequency response: 20Hz–20kHz, +0/–0.2dB. Maximum output level: 2.25V (single-ended), 4.5V (balanced). Output impedance: 50 ohms (single-ended), 50 ohms per phase (balanced). Signal/noise ratio (A-weighted): 119dB (single-ended), 122dB (balanced). Power requirement (via USB): 480mA.
Dimensions: 3.8" (97mm) W by 3" (77mm) H by 6" (…

HRT Music Streamer HD USB D/A processor Associated Equipment

Sidebar 2: Associated Equipment

Analog Sources: Garrard 301, Thorens TD 124 turntables; EMT 997, Artemis Lab TA-1 tonearms; Ortofon SPU, EMT TSD 15 70th Anniversary pickup heads; Miyabi 47 cartridge.
Digital Sources: AudioQuest DragonFly, Wavelength Proton, Halide DAC HD USB DACs; Apple iMac G5 computer running Apple iTunes v.11.0, Decibel v.1.0.2 playback software; Sony SCD-777ES SACD/CD player.
Preamplification: Auditorium 23 Standard (SPU version), Hommage T2, Silvercore One-to-Ten step-up transformers; Shindo Masseto preamplifiers.
Integrated amplifier: Ayre Acoustics AX-…

HRT Music Streamer HD USB D/A processor Measurements

Sidebar 3: Measurements

My testing of the HRT Music Streamer HD was primarily performed with Stereophile's loan sample of the top-of-the-line Audio Precision SYS2722 system (see www.ap.com and the January 2008 "As We See It"), with some tests performed on my vintage Audio precision System One. The sources for the tests were WAV and AIFF files played from my MacBook Pro running BIAS Peak Pro and connected to the HRT with the Music Streamer set to USB2.0. I checked that the sample rate and bit depth were correctly set for each file with the Audio-MIDI setup utility. Bit depth was set to "…

Shindo Masseto Follow-Up, June 2013

Art Dudley returned to the Shindo Masseto in June 2013 (Vol.36 No.6):

I hesitate to say "Let's recap" to an audience whose members have been, on occasion, a bit overeager to stuff their audio electronics, contemporary and vintage alike, with the condensateurs du jour. Suffice it to say, the time has come for another look at Shindo Laboratory's Masseto preamplifier ($13,500, footnote 1) taking into account a few things that may affect all Shindo shoppers, past and prospective alike.

Of course, the notion of a Follow-Up carries with it a message of uncertainty—that things change,…

TAD C600 line preamplifier

In the early 1970s, Stereophile's founder, J. Gordon Holt—a man I used to describe, with all due respect, as having been clothed by the haberdasher to the homeless—said that Audio Research's SP-3 tubed preamplifier was "the closest thing available, in fact, to the ideal straight wire with gain" ie, it would amplify the signal without editorializng in any way. Back then, the SP-3 cost $595. Today it would cost around $3500. But TAD's C600 dual-mono, solid-state, balanced preamplifier costs more than 10 times that: $42,000.

Much of what's under the hood of the high-tech C600 would probably…

TAD C600 line preamplifier Page 2

All we ask is a usefully low output impedance, to drive potentially long cables connected to a (hopefully) high-input-impedance power amplifier sensitive enough to be driven to full output by a few volts, so that the preamplifier primarily acts as an attenuator—though of course we also want the preamplifier to be able to produce gain, particularly those of us who listen to vinyl; many combinations of cartridge and phono stage don't produce enough voltage to drive an amplifier to full output.

In the real world, though, while most preamplifiers get right the impedance/attenuation/gain/…