The rather bulky, but surprisingly lightweight (for its size and power) M-508 is a true dual-mono design, consisting essentially of two completely separate amplifiers on a single chassis. That it is not designed for outstandingly high current capability is…
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"Grand Integra" is the name Onkyo has given to its line of perfectionist-oriented audio products, and the M-508 is the cheaper of Onkyo's two Grand Integra power amplifiers. (The flagship model is the $4200 M-510, reviewed by Larry Greenhill in Vol.8 No.8, featuring "high current capability," and rated at 300W continuous per channel.)
Sidebar: Specifications
Description: Dual-mono, single-chassis, class-AB power amplifier. Rated power: 200W into 8 ohms. Power bandwidth: 20Hz-20kHz. THD at rated output: 0.003%.
Dimensions: 18.25" (with wood end panels) by 7.25" H by 17" D. Weight: 55 lbs.
Price: $1150 (1987); no longer available (2012).
Manufacturer: Onkyo USA Corporation, 18 Park Way, Upper Saddle River, NJ 07458. Tel: (800) 229-1687. Fax: 201-785-2650. Web: www.onkyousa.com.
With the introduction of Audio Alchemy's Digital Transmission Interface (DTI) more than three years ago, the company created an entirely new category of hi-fi product: the jitter filter. The original DTI was a good start, but didn't always improve the sound of the better-quality digital front-ends.
The DTIPro, released 18 months later, bore little similarity to the rather simple DTI. The Pro added a more sophisticated dual Phase-Locked Loop (PLL) input receiver for much lower jitter, and also performed a new type of Digital Signal Processing (DSP) that Audio Alchemy called "Resolution…
Setting up the DTIPro 32 and choosing its output word length requires the owner's manual; there's no direct readout of the 32's operating status. You must instead interpret a code provided by the three power-indicating LEDs. For example, 20-bit output is indicated by illumination of only the bottom two LEDs. Without the owner's manual (or a great memory), you won't be able to correctly set up the Pro 32 for your system.
To change the output word length, press and hold the "Phase" button until the three power-indicating LEDs switch from power indication to operational status indication…
Sidebar 1: Review System
Most of my experience with the DTIPro 32 was in my usual system, consisting of a Sonic Frontiers SFL-2 preamplifier driving a pair of Audio Research VT150 monoblock power amplifiers. Loudspeakers were Genesis II.5s, whose woofers were driven by an integral servo power amplifier. Interconnects in the Sonic Frontiers/ARC/Genesis system were AudioQuest Lapis, Diamond X3, and Wire World Gold Eclipse, and loudspeaker cables were short runs of AudioQuest Dragon II.
Digital front-ends with which I tried the DTIPro 32 include the Mark Levinson No.31 and Sonic…
Sidebar 2: Measurements
I started by looking at the DTIPro 32's effect on low-level signals alternately in bypass mode, and then with the Resolution Enhancement processing engaged. I performed wideband third-octave spectral analysis, waveform capture, and FFT-derived spectral analysis on a variety of signals, but saw no difference in the noise level, noise-floor spectrum, or even the presence of dither. I also tried to measure the DTIPro 32's effect by looking at the output of the DDE v3 processor with and without the DTIPro 32 in the signal path. Again, the DDE v3's low-level…
Sidebar 3: Specifications
Description: Jitter filter and resolution-enhancement device. Inputs: S/PDIF coaxial on BNC, S/PDIF TosLink optical, I2S bus (ST-type optical optional). Outputs: S/PDIF coaxial on BNC, I2S, AES/EBU, ST-Type optical. Output word length: 16, 18, 20, 22, 24 bits (user-selectable).
Dimensions: 8.5" W by 2" H by 7" D. Weight: 7 lbs (shipping).
Serial number of unit tested: 83317.
Price: $1595. Approximate number of dealers: 180.
Manufacturer: Audio Alchemy Inc., Westlake Village, CA 91362 (1996). Company no longer in existence (2012).
According to designer Bill Reed, the Nelson-Reed 8-04/B was not originally intended to be an audiophile speaker system, but was instead designed as a high-quality monitor for the critical recording engineer who wanted to be able to walk from the studio into the control room and hear the same thing from his speakers that he heard "live." The fact that modern studio mike technique ensures that this could never happen is probably beside the point. The point is that reproducing the original power and dynamic range of live music is a formidable challenge, which practically no audiophile speakers…
JGH returned to the Nelson-Reed 8-04/B in July 1988 (Vol.11 No.7):
Subsequent to my initial tests of the 8-04/B, I moved the speakers into my video room and tried them for reproducing film soundtracks. I wasn't too surprised to find them superb for this application. Dialog intelligibility was better than it has ever been before, their tremendous dynamic range gave unprecedented impact to blockbuster soundtracks, and their outstanding imaging capability revealed something I had never noticed before, nor even thought about before: The sounds of moving objects often don't track their visual…
Sidebar 1: Review System
Equipment used for my tests included the Ortofon MC-3000 cartridge with its T-3000 stepup transformer, the Well-Tempered Arm on the Sota Star Sapphire turntable, Sony CDP-705ESD, Rotel 965, and Proceed CD players, CD player, a Sony PCM-F1 digital processor and SL-2000 VCR, Pioneer LD-S2 laserdisc player, an Enlightened Audio Design D/A converter, the Threshold FET-10 preamp and line controller, Audio Research SP9 II, and Octave Research, Boulder 500AE, Threshold SA-1, Sonic Frontiers SFS-80, and Audio Research M300 power amplifiers. Audio interconnects were…