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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…

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…

While working on this review, I…

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"—…

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…

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…

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…

Although I preferred the PCM63-fitted Numerik to one with the 1702 DAC, I heard none of the objectionable characteristics when the PCM1702 was combined with the SPS. The treble was pure and clean again, and the midrange was restored to its former liquidity. Linn has really hit on something with the switching power supply. I'm forced to agree with their claim that the new supply "transforms" the sound of the Numerik.

Next,…

The Karik had a maximum output level of 1.96V when playing a full-scale, 1kHz sinewave. Its output impedance measured just under 100 ohms at any audio frequency. DC-offset levels were below the voltmeter's sensitivity, implying that any DC was less than 500µV. The Karik doesn't invert absolute polarity; a positive-going impulse on a CD produces a positive-going impulse at the Karik's analog output. Frequency response and de-emphasis error (fig.1) were both excellent. Unlike most players, the Karik had no rolloff at 20kHz. The de-emphasis circuit had a…