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Although fig.1 reveals a lack of top-octave in-room energy, due, as my November 1998 measurements showed, to the tweeter's restricted dispersion in this region, there was simply too much treble energy apparent. It wasn't that the SC-IVA was bright as such, or that the highs were colored (though there was a narrow brand of presence-region brightness that gradually disappeared as I racked up the hours). But the upper mids and high frequencies consistently sounded somewhat shelved-up. This was not enough to make the speaker lack integration between its upper and lower ranges, but it did give…
Sidebar: Associated Equipment
Digital source: Mark Levinson No.31.5 CD transport and No.30.6 D/A processor connected with Illuminations Orchid AES/EBU datalink, California Audio Labs CL-20 DVD player, Pentium MMX 166MHz running Windows 98, WinAmp 2.5, and CoolEdit 2000, with Digital Audio Labs CardDeluxe soundcard connected to dCS 972 upsampler via Canare 75 ohm S/PDIF link.
Preamplification: Mark Levinson No.380S, Z-Systems rdp-1 digital control center (updated to handle 96kHz sources).
Power amplifiers: Mark Levinson No.33H monoblocks.
Cables: Madrigal CZ Gel-1 balanced…
Leisure duds on? Bathrobe 'n' pipe, Ol' Yaller at yer feet and slobberin' all over your ankles? All's well with the world? Then it's time for "Fine Tunes"! May audio mayhem ensue...
This month's first tweak fits the Fine Tunes bill perfectly, and is aimed at owners of MartinLogan or other electrostatic speakers, with a tip applicable to moving-coil speakers as well.
Mark Gdovin (markgdovin@hotmail.com), a regular contributor to the "Soapbox" debates on www.stereophile.com, is crazy about the inexpensive back-wall treatment he's cooked up for his dipole MartinLogan Aeriuses. His…
The Jeff Rowland Design Group has long been renowned for the exquisite quality of its chassis. The company was one of the first to promote fully balanced topologies in preamplifiers and amplifiers in the high-end market, one of the first to offer a sonically acceptable remote control, and one of the few to offer a battery power option for their amplifier line.
In the past few years Jeff Rowland has revamped his entire product line in an effort to elevate performance to the highest level. For his new preamps, he has reexamined mechanical, thermal, electrical, and interface parameters in…
In addition to the detachable front faceplate, Rowland ships a slim, hand-held wireless remote with a reduced feature set offering input selection, gain adjustment in 0.5dB steps, balance control, and mute. Personally, I'd trade the two Balance buttons for remote polarity selection. In any event, it's easy to accidentally hit a Balance button instead of Volume on the remote; double-check the tiny front-panel indicator lights occasionally.
Modular design
The six aluminum modules that form the heart of the Coherence are mounted to the chassis floor with elastomeric grommets for…
Following the RIAA stage, a very robust INA-103 instrumentation amplifier buffers the unit's output and allows the Cadence to drive long lines and capacitive loads with relative ease. The Cadence can be powered by the second output on the Coherence's battery power supply, or can be bought as a standalone unit with either its own battery or an AC-only supply.
A sonic reference
The credo to which any top-drawer preamplifier must aspire is also of paramount importance to me as a reviewer and music lover: First, do no harm. While no preamp I've evaluated is truly transparent, a few at…
Sidebar 1: Specifications
Coherence: Three-piece-piece solid-state, transformer-balanced, line-level remote-control preamplifier. Inputs and outputs on XLR connectors (pin 3 wired as noninverting). Volume Control range: 63.5dB in 0.5dB steps. Preset Gain Range: 0-20dB. Frequency response: 0.5Hz-160kHz, -3dB. Channel separation; >110dB, 20Hz-20kHz. Input impedance: switchable between 18k and 600 ohms. Maximum input level: 13V RMS (0dB gain). Output noise level: 12µV, 20Hz-20kHz (0dB gain). S/N Ratio; >96dB. Power supply: AC-assisted, microprocessor-based rechargeable battery power…
Sidebar 2: Transformers and the Audio Interface
The majority of Jeff Rowland's new products are equipped with line-level input transformers. In the early days of stereo, the use of transformer-coupling components in the recording studio was the norm. Nearly all of the most prized recordings of the late 1950s and '60s were captured through a whole chain of these passive devices. Because at that time construction of good line-level transformers was more of an art than a science, quality was understandably variable. In addition, limitations in material quality, knowledge, and precision…
Sidebar 3: Associated Equipment
Analog source: Immedia RPM-2 turntable and unipivot tonearm, Lyra Da Capo and Sounds of Silence Crown Jewel cartridges.
Digital sources: Transports: Muse Model Eight (DVD/CD), Resolution Audio VT-960 (CD), Sonic Frontiers Transport-3 (CD), Pioneer DV-500 (DVD/CD). Processors: Muse 296 (DVD/CD), Sonic Frontiers Processor-3 (CD), Muse Model Two-Plus (CD), Resolution Audio D-92 (DVD/CD).
Preamplification: Z-Systems RDP-1 digital preamp, BAT VK-40, BAT VK-3i, Muse Model 3 Plus, Audio Research LS22, Sonic Frontiers SFL-2, Jeff Rowland Design Group…
Sidebar 4: Measurements
Coherence: Although the Coherence can be used with single-ended-to-balanced adapters, it is a true balanced design, so all the measurements were done in balanced mode. The Coherence inverted signal polarity, as Jeff Rowland adheres to the older US convention of wiring pin 3 of the XLR to be "hot" rather than pin 2, as the AES now recommends. The input impedance was 11k ohms in the normal setting, 690 ohms in "terminated" mode; the output impedance was a low 55 ohms across the audio band.
The volume control operated in accurate 0.5dB steps up to an…