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The center-tapped AC from the remote power supply is rectified to raw ±30V DC supplies, these dropped by RC filters to ±22.5V rails that are further isolated and smoothed for each channel's line and phono stages. Contrary to modern practice, where engineers reach for a pair of three-terminal regulator chips almost by reflex, there is no voltage regulation at all in the YBA 2. Yves-Bernard André feels strongly that if the circuit is both complementary and symmetrical, and the layout of the signal paths on the printed circuit board are very carefully arranged, then noise, parasitic ground…
The YBA's MM phono stage didn't have enough gain for the low output of my Linn Arkiv cartridge. This was a shame, as the sound, while quiet, was astonishingly transparent (particularly in Bypass mode). There was also no background electronic hiss audible, despite my having to use the preamp with the volume control all the way up. An LP edition of Mark Isham's fabulous 1983 collection of minimalist sound paintings, Vapor Drawings (Windham Hill WH-1027), that I recently picked up at a garage sale, had every little sonic detail laid out for my inspection, yet without those details being spotlit…
Sidebar 1: Specifications
Description: Solid-state, full-function stereo preamplifier with five line inputs, one phono input, and one tape loop. Frequency responses: 5Hz-400kHz, -0.2dB, line; 5Hz-60kHz, -0.2dB, phono. Input sensitivity: 2mV RMS (MM phono); 150mV RMS, line, both for 1V output. Input impedance: 47k ohms, MM phono; 100k ohms line. Output impedance: ±20 ohms. Maximum output: 8V RMS. RIAA overload: 2.2V RMS (frequency not specified). S/N ratio (ref. 1V output at 1kHz): 100dB, line; 90dB, MM phono. Absolute polarity: inverting.
Dimensions: preamplifier: 16.9" (430mm) W by…
Sidebar 2: System
The main comparison preamplifier was the Melos SHA-1 headphone amplifier used as a line-stage (footnote 1), while the Mod Squad Line Drive Deluxe and the Classé Six reviewed by Larry Greenhill in February (footnote 2) also saw some action. Power amplifiers included the YBA 2 HC, Mark Levinson No.20.6es, and Audio Research Classic 120s.
Loudspeakers used during the review period included the B&W Silver Signatures, Velodyne DF-661s, and Green Mountain Diamantes, for both preamps, with Epos ES11s, Magnepan MG2.6/Rs, Spendor S100s, Acoustic Energy AE1s, Thiel…
Sidebar 3: Measurements
The YBA 2's maximum line-stage gain for all the inputs other than Aux measured a sensible 16dB at 1kHz. The internal resistor in series with the Aux input reduced the gain to 6.7dB, which will be enough for sources with very high outputs—the Theta processors, for example. The MM phono-stage gain, measured at the tape outputs, was 34.1dB. Line input impedances were lower than specified, at 30k ohms, though the Aux offered 85k, due to the resistive padding. The MM phono input impedance, measured at 1kHz, was 54k ohms.
Both line stage and phono stages…
More important than the level of any distortion present is its spectral content: high, odd-order harmonics—seventh, ninth, eleventh—are much more audible than low harmonics, such as the second or third. (I illustrate this phenomenon on Stereophile's Test CD 2: tracks 21-23 allow you to compare the audibility of various amounts of pure second-, third-, and seventh-harmonic distortion superimposed on a 1kHz tone. Even 0.1% of seventh is easily audible, whereas 1% of second is not.) To look at the YBA 2's distortion signature, I drove it hard into 100k ohms with a 50Hz sinewave; the spectrum of…
Jonathan Scull wrote a Followup on the YBA 2 in October 2000, (Vol.23 No.10):
The YBA 2 preamplifier is a slim, elegant device with an external power supply running on the by-now-familiar YBA Family Values ticket. First, it's tweaky—and last, it's tweaky! If you've purchased the Ligne version that I auditioned, the Bypass selector switch offers the most direct signal path for either the moving-magnet phono input or the CD input. The second-best inputs, as suggested in the manual, are the Tape In connectors, with the rest of the inputs functionally the same.
Peering inside, one…
CHRIS STAMEY: Travels In the South
Yep Roc 2033 (CD). 2004. Chris Stamey, Jefferson Holt, prods.; Don Dixon, Greg Elkins, prods., engs.; Tim Harper, Brian Paulson, John Plymale, Wes Lachot, Logan Matheny, Dan Korneff, engs. AAD. TT: 52:30
Performance ****
Sonics ***
Yep Roc 2033 (CD). 2004. Chris Stamey, Jefferson Holt, prods.; Don Dixon, Greg Elkins, prods., engs.; Tim Harper, Brian Paulson, John Plymale, Wes Lachot, Logan Matheny, Dan Korneff, engs. AAD. TT: 52:30
Performance ****
Sonics ***
Power pop may well be the hardest of all the rock-related genres. To be successful, you've got to crank out a steady stream of catchy, hook-filled melodies—and as anyone knows who's ever tried to write a song, those are damned hard to come by. After Mozart, Gershwin and the Beatles in their early years, few have…
The August issue of Stereophile, number 247, is the very last to be produced out of the "City Different" in the "Land of Enchantment" (Santa Fe, New Mexico). Known for its energetic mix of Native American and Latino cultures, its geographic mix of high desert and mountains, its 300 days of clear blue, cerulean skies, its opera and chamber music seasons, and not forgetting that most important culinary question—"red or green"—the oldest established city in the US is not the first place that comes to mind in the magazine business. But, after publishing 39 issues of Stereophile out of rainy…
The first time I encountered Dunlavy's Signature Collection loudspeakers was at the 1993 Chicago Summer CES. I was familiar with, and had a lot of respect for, the speakers John Dunlavy had designed for the Australian Duntech brand, but I thought this new line clearly transcended his previous efforts—and at significantly lower prices. The model that I ended up reviewing—and, after the review (Vol.17 No.4), buying—was the SC-IV, subsequently honored as Stereophile's 1994 Loudspeaker of the Year and Product of the Year. In 1995, the SC-IV underwent changes, including a new woofer and a…