Analog Sources: Simon Yorke S7, Immedia RPM-2, Graham Engineering Phantom tonearms; Lyra Titan Stereo & Mono, Dynavector DRT-XV1S, Mysonic Lab Eminent cartridges.
Digital Sources: Musical Fidelity kW SACD player, Alesis Masterlink hard-disk recorder.
Preamplification: Manley Steelhead, Boulder 2008 phono preamplifiers; Musical Fidelity kW, kWP preamplifiers.
Power Amplifiers: Musical Fidelity kW, kW750.
Loudspeakers: Wilson Audio Specialties MAXX2.
Cables: Phono: Crystal Cable Piccolo, Hovland MG 2 Music Groove. Interconnect: Acrolink…
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Sidebar 2: Associated Equipment
"You're reviewing a class-D amplifier?" whined John Atkinson. "I hate measuring those."
"Because they measure badly? Dusty Vawter assures me this one measures pretty well."
"It's not that they measure badly, it's because I have to be extremely careful to ensure that I don't end up measuring my test equipment's limitations."
"Does that mean class-D actually measures better than other amps?"
"Let's just say the D stands for different."
Yes, let's. And Channel Islands' D-100 monoblock is more different than most. It's small (6.25" wide by 5.5" high by 8.0"…
"Some of the other class-D amplifiers use switching power supplies, but I just don't think they sound good enough yet to use in audiophile amplifiers—they're probably all right for subwoofers, but I still think a linear supply is the best thing for an audio amplifier.
"I don't pretend there's anything especially sophisticated about the D-100's power supply. It uses a custom 300VA toroid, and it uses discrete Schottke diodes in the bridge rectifier. We use eight parallel capacitors—we like paralleling caps rather than just using two with large values because that tends to lower the…
Sidebar 1: Specifications
Description: Class-D monoblock power amplifier. Power output: 100W into 8 ohms (20dBW), 175W into 4 ohms (19.4dBW). Input impedance: 100k ohms. Voltage gain: 32dB (version for use with passive preamplifier), 26dB (version for use with active preamplifier).
Dimensions: 6.25" (160mm) W by 5.5" (140mm) H by 8.0" (205mm) D. Weight: 15 lbs (6.8kg).
Serial numbers of units reviewed: DM1616, DM1617.
Price: $1599/pair. Approximate number of dealers: 2 (sold direct through Music Direct and Channel Islands Audio). Warranty: 1 year parts & labor.
…
Sidebar 2: Associated Equipment
Digital Source: Ayre C-5xe universal player.
Preamplifiers: Ayre K-5xe, Conrad-Johnson ACT2.
Power Amplifiers: Coda Technologies S5.
Loudspeakers: Dynaudio Special 25, Thiel CS1.6, Peak Consult Empress.
Cables: Interconnect: Cardas Audio Golden Reference, Shunyata Research Aries. Speaker: Cardas Audio Golden Reference, Shunyata Research Lyra, Stereovox HDLS. AC: Cardas Audio Golden Reference, Shunyata Research Anaconda.
Accessories: Shunyata Research Hydra AC power-distribution system; Solid-Tech Rack of Silence equipment stand, Feet of…
Sidebar 3: Measurements
Wes Phillips mentioned at the start of this review that I dislike measuring amplifiers with a class-D output stage. This is because such designs can throw out enough ultrasonic noise that you can never be quite sure that what you're actually measuring is the input stage of your analyzer being driven into slew-rate limiting. (For more on this subject, see the measurements sidebar accompanying Michael Fremer's review in April of the class-D Yamaha MX-D1.) What I do, therefore, is to insert, when appropriate, a sixth-order low-pass filter set to 20kHz or 30kHz…
John Atkinson wrote again about the D-100 in September 2005 (Vol.28 No.9):
When I measured the tiny CIA D-100 for Wes Phillips' review in August (p.113), I found that while this class-D power amplifier met its 100W power specification into 8 ohms, it failed to do so into 4 or 2 ohms. I thus recommended that the amplifier not be used with speakers whose impedances dipped below 4 ohms. CIA's Dusty Vawter addressed this point in his "Manufacturer's Comment" in that issue (p.141): "the low figures shown at 2 and 4 ohms are not due to lack of headroom, but are a result of premature current…
When the Compact Disc was first introduced nearly ten years ago, many were critical of the sound quality from this medium that promised "Perfect Sound Forever." To many sensitive listeners digital playback was a travesty that paled by comparison to even modestly priced turntable/arm/cartridge combinations. Ironically, those listeners who first praised CD sound have been forced to recant when confronted by the huge improvements in digital to analog conversion (and A/D conversion) seen in the past few years.
No one was more critical of CD than Linn Products and its founder and guru, Ivor…
The Numerik has no front-panel controls or displays; the usual indicator lights (sampling rate, lock, etc.) are instead found on the rear panel. Although the Numerik has two digital inputs, no input selector switch is provided. Here's how it works: With the Karik connected to input #1, turning off its digital output from the front panel causes the Numerik to default to input #2. The Karik's digital mute switch thus functions as the Numerik's input selector. This unusual feature permits operation of the Numerik in an inaccessible location. Neat.
Sampling-rate selection (44.1kHz or 48kHz)…
The Numerik
The Numerik is similarly forward-thinking in design. The unit uses a brand-new chip set not yet seen in any other D/A converter.
The Numerik is similarly forward-thinking in design. The unit uses a brand-new chip set not yet seen in any other D/A converter.
The digital filter is an 8x-oversampling unit from Burr-Brown, the DF1700. This linear-phase filter has 20-bit word output and 25-bit internal word length. I haven't seen this filter used before; most converters use the NPC or Sony digital filters.
D/A conversion is handled by dual Burr-Brown PCM63P DACs, another brand-new part. This 20-bit monolithic DAC, called a "Sign-Magnitude" converter, has some impressive performance…