Manufactured and marketed by Spatial, Inc. for three years (the last reference I was able to find was the 1981 Audio magazine annual equipment guide), its claim to fame…
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There are some standing jokes in the audio industry about the qualities a piece of equipment must have in order to be truly "high-end." One definition is that it must be unavailable, unreliable, and dangerous. Another is that it will sound great, break, and its manufacturer go out of business. By meeting at least half of these variables, the Spatial Coherence TVA-1 preamplifier qualifies as a classic audiophile product.
Sidebar 1: Associated Equipment
Turntable: VPI HW-19 Mk.II fitted with the Well-Tempered Arm and Ortofon X-5MC cartridge; CD player: Musical Concepts modified Magnavox 1040; Power amplifiers: Belles Model One, plus a 180Wpc amp of my own construction; Speakers: Legacy-1; Interconnects: Mogami Neglex; Speaker cable: LiveWire BC-4. The Spatial Coherence was auditioned alone and in a side-by-side comparison with a Harman/Kardon Citation 21.
Source material used: LPs: The Scott Hamilton Quintet in Concert (Concord Jazz CJ-233); The King James Version, Harry James and his Big Band (…
Sidebar 2: Specifications
Description: Full-function solid-state preamplifier with two phono inputs, three line-level inputs, two tape loops with selectable two-way dubbing. Original published specifications: Frequency response: 10Hz–40kHz +0, –0.5dB. Max output: 10V. THD: 0.05%. IMD: 0.05%. Phono S/N ratio: 80dB. Measured performance (footnote 1): RIAA accuracy: R channel, –0.25dB at 20Hz, –0.75dB at 20kHz (net: ±1dB); L channel, –0.25dB at 20Hz, –0.25dB at 20kHz (net: ±0.5dB). Line level frequency response: R channel, 20Hz–30kHz, +0dB, –0.1dB; L channel, 20Hz–30kHz, +0.5dB, –0.1dB.…
Today is March 22, 2020. Outside my door, the plague is gaining intensity. People are wearing masks and rubber gloves. But outside the window by my desk, there is a Callery pear tree, and every day its blossoms are becoming more intensely white. Each day its brightness (measured in units of luminous flux) increases noticeably. The optical radiance of its zillion-petal whiteness illuminates the whole garden.
Looking out that desk window, I notice also the spring-warmed radiance of the sun, the racing shadows of ravenous sparrows, and daffodils. Each one of those things, in its way, affects…
The HEDDphone's rectangular AMT drivers are installed into a conventional-looking but very solidly built (718gm!), circumaural, open-back headset with thick, tight-fitting ear cups that cupped my ears with greater bulk and pressure than I have previously experienced with headphones.
But that is okay. Form must follow function.
At 42 ohms and 87dB/mW, the HEDDphone is easier to drive than the 83.5dB/mW HiFiMan HE6se and about the same difficulty as the 47 ohm, 88dB/mW Abyss AB-1266 TCs, which means it still requires extra gain and current to sound its best.
I…
Spectral is a bit of an enigma in the high-end audio world. Although nearly 20 years old and one of the founders of the American high-end audio industry, Spectral isn't a name that comes quickly to mind when considering the best of the best in high-end.
Spectral's low profile is of their own choosing. They advertise very little, their products are demonstrated in a small number of stores, they almost never send products to magazines for review, and they are very quiet about their accomplishments. Rather than push their products on customers, they seem to let a small segment of the market…
The analog filter is a passive, fourth-order type designed for high out-of-band attenuation, low phase shift, and good transient response.
The analog output stage is based on the circuits Keith Johnson has been refining for more than 20 years. The SDR-2000 Pro's output stage is very similar to the electronics used throughout the signal path in Keith's recording electronics, which are used to make all the Reference Recordings releases. The circuit features a differential JFET input stage and a MOSFET cascode, followed by a differential cascode voltage-gain stage. High-current power…
Thomas J. Norton wrote about the Spectreal in November 1995 (Vol.18 No.11):
RH salivated over the Spectral SDR-2000 Professional HDCD D/A processor in Vol.18 No.5, and this was my first chance to hear it in my system. He did not exaggerate. It is clearly a Class A processor; it may even be the best processor in Class A, though I haven't had the opportunity to compare it directly with the Mark Levinson No.30.5, which isn't exactly chopped liver (footnote 1).
At first I found the differences between the SDR-2000 and the Mark Levinson No.36 D/A converter to be subtle—less notable…
Sidebar 1: Specifications
Description: Digital Processor with HDCD decoding. Inputs: three coaxial on RCA jacks, two AES/EBU on XLRs, TosLink optical, Spectralink. Controls: digital input select, polarity inversion, mute, display dim, operate/standby. Sampling rates supported: 44.1kHz, 48kHz. D/A conversion: four custom 20-bit DACs in balanced configuration. Digital filter: Pacific Microsonics PMD100 8x-oversampling. Analog filter: passive, linear phase to 22kHz. Frequency response: DC–22kHz ±3dB (limited by encoding). DAC step resolution: 5µV or less. Digital noise output: 100µV p-p or…
Sidebar 2: Robert Harley's System
I listened to the SDR-2000 Pro at the front of my usual reference system, and with an all-Spectral playback system with MIT loudspeaker cables and interconnects. The people at Spectral believe that their electronics and MIT cables are needed to fully hear the SDR-2000 Pro's musical performance. Although I agreed to replace my usual amplification and cables for part of this review, auditioning the SDR-2000 Pro in my familiar reference system was mandatory.
My system consisted of a Mark Levinson No.31 CD transport feeding the SDR-2000 Pro via…