No one was more critical of CD than Linn Products and its founder and guru, Ivor…
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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.
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…
Well, how does the long-awaited Linn CD Player sound?
Like no other digital processor I've auditioned. The Linn's musical presentation was very different from those of other digital products. In a nutshell, it was gentle, smooth, intimate, delicate, and had a remarkable sense of ease.
One of the first presentation aspects to strike me about the Linn was its laid-back character. The music was set back between and behind the loudspeakers rather than thrust forward. The word "vivid," used to describe some digital processors' presentations, certainly didn't apply to the Linn. There…
Without hearing the effect of the separate sync cable, one would not suspect something was missing. But plugging it back in returned the magic and threw into sharp relief the Linn's best attributes. These impressions were repeated with a variety of music. It's tragic that a separate sync cable was not made part of the S/PDIF standard. Just because the mass market chooses to ignore this source of major improvement, the High End shouldn't accept this compromise. All high-end digital transports and processors should have a separate sync cable (footnote 2).
While working on this review, I…
Sidebar 1: In Sync!
The Linn CD player completely sidesteps a problem that plagues all other CD transport/processor combinations: jitter in the recovered clock. Linn's method is so simple I'm surprised no one else has done it before. In fact, I'm surprised that the S/PDIF (Sony/Philips Digital Interface Format) standard didn't incorporate this technique when the interface standard was established. But before looking at Linn's solution, let's see how a conventional transport and D/A converter interface works.
The S/PDIF output of a CD transport—the RCA jack marked "Digital Out"—…
Sidebar 2: 1992 Review System
I auditioned the Linn CD player with three different pairs of loudspeakers that made their ways through my listening room over the past weeks: the Monitor Audio Studio 20 reviewed last month, the Apogee Centaur Minor reviewed in this issue, and my reference system, the Hales System Two Signatures augmented by a Muse Model 18 subwoofer. VTL 225W monoblocks were the primary amplifiers—a Jeff Rowland Model One saw brief action—and an Audio Research LS2 line-stage preamplifier provided gain and switching control. Interconnects were Straight Wire Maestro and…
Sidebar 3: 1992 Measurements
The Numerik put out 2.135V when decoding a full-scale, 1kHz sinewave. This is only slightly higher (0.57dB) than the CD standard of 2V. Channel balance was the best I have measured, the right channel being just 0.004dB higher in output than the left. Digital converters often have a few tenths of a dB channel imbalance.
Frequency response (fig.1) was flat, rolling off an almost negligible 0.5dB at 20kHz. Note the virtual overlap of the left and right traces, confirming the almost perfect channel balance. Fig.2 is the Numerik's de-emphasis error. A…
Robert Harley wrote again about the Karik/Numerik in October 1994 (Vol.17 No.10):
Back in January 1992 (Vol.15 No.1), I reviewed the Linn Karik CD transport and Numerik digital processor pair, the first digital components from Linn Products of Scotland. I found them eminently musical, technically sophisticated, and worthy of a Class A recommendation in Stereophile's "Recommended Components."
Although the Karik's mechanism and electronics remain unchanged, the unit is now a CD player as well as a transport. Linn simply installed a D/A board without increasing the $3395 retail…
Because of the rapid turning on and off of their transistors, switching supplies radiate high-frequency noise, some of which gets into and pollutes the adjacent audio circuits, which is one reason they generally haven't been used in audio components (footnote 2), [David Berning's amplifiers are the only high-profile designs to use switching supplies since the demise of the Infinity and Sony PWM amplifiers.—Ed.] Linn believes that they've overcome this limitation, claiming not only to have solved the radiated noise problem, but also suggesting that the new power supply "transforms" the…