To generate sufficient force, the wire in a moving-coil driver must be many meters long and so is…
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As Hans Christian Oersted, the Danish physicist and founder of electrodynamics, discovered in 1819, an electric current passed through a wire generates a magnetic field. Place that wire close to a permanent magnet and the interaction of the two fields will generate a force. That, in two sentences, summarizes the operating principle of the motor that energizes every moving-coil drive-unit in millions of loudspeakers worldwide. It sounds simple, but—like everything in audio—it isn't.
A current source, by contrast, has an output impedance that is large compared to the load impedance, so that now its output current is largely unaffected by fluctuations in load impedance. This is significant in the context of thermal compression because it is the current through the voice-coil that generates the driver's motive force. If this is unaffected by changes in voice-coil resistance, then thermal compression cannot occur.
The trouble is, you can't simply substitute a current-source amplifier for a voltage-source amplifier when the loudspeaker expects to see a voltage source.…
Sidebar: Making The Measurements
The simplest way to determine a device's electrical resistance is to pass a known DC current through it, measure the voltage developed across it, and use Ohm's Law (voltage equals current times resistance; ie, resistance equals voltage divided by current) to calculate the required result. This is essentially the method used here and previously employed by others (footnotes 1, 2), although it is complicated somewhat by the need to perform the measurement in the presence of a large AC signal driving the loudspeaker. Key issues are: 1) isolating the DC-…
We were driving to a friend's house to celebrate her dad's 92nd birthday. Halfway there, a bright yellow, ground-hugging insect pulled in front of my car from across street. "Wow, that's a Lamborghini Countach!" I exclaimed. You don't often see one of those in my neighborhood—or in any neighborhood.
"What is?" my mother-in-law responded without irony. "That car!" I squeaked, staring transfixed at the car's least dramatic angle. My childlike tone had my wife and mother-in-law chortling until, still mesmerized, I missed a familiar turn and began involuntarily following the…
However, switching the Zanden DAC to the I2S input took the sound to an exalted level of clarity, suppleness, transparency, and precision. Now the CD-R recorded from analog sounded almost as good as analog, and certainly better than any digital I've heard here.
At the 2005 Hi-Fi News show in London, the Audiofreaks room featured an all-Zanden system driving Avalon speakers. Compared to most of what I heard that weekend, that room was an oasis of smooth, musical flow and utter ease and grace. I lingered there a long time listening to CD-Rs I'd recorded from analog and brought along. The…
Sidebar 1: Specifications
Description: Four-box, 16-bit/44.1kHz CD player with separate transport and DAC, each with separate power supply. DAC power-supply tube complement: two 6CA4, one 6X4. Formats supported: CD, CD-R, CD-RW. Transport output: 16-bit/44.1kHz via S/PDIF, AES/EBU, I2S; word clock. Transport output jacks: S/PDIF BNC, AES/EBU XLR, I2S; word clock BNC. DAC input jacks: S/PDIF (RCA and BNC), AES/EBU (XLR), I2S. DAC input frequency: 44.1kHz. Total harmonic distortion: not specified.
Dimensions: Transport: 15.6" (400mm) W by 5.4" (140mm) H by 15.6" (400mm) D. Power supply…
Sidebar 2: Associated Equipment
Analog Sources: Continuum Audio Labs Caliburn, TW-Acoustic Raven turntables; Continuum Cobra, Graham Phantom tonearms; Lyra Titan stereo & mono, Blue Angel Pink Ivory, Transfiguration Orpheus cartridges.
Digital Source: Alesis Masterlink BPT-modified hard-disk recorder.
Preamplification: Manley Steelhead, Oracle Temple phono preamps; Musical Fidelity kWP preamplifier.
Power Amplifiers: Musical Fidelity kW monoblocks.
Loudspeakers: Wilson Audio Specialties MAXX 2.
Cables: Phono: Cardas, Hovland Music Groove 2. Interconnect: TARA Labs Zero…
Sidebar 3: Measurements
First, it must be noted that Zanden doesn't have enough dealers to qualify for a full review in Stereophile. At the time the review was organized I was under the impression that the Zanden gear was available from five US dealers, the minimum we require. But as we went to press, we were informed that Zanden has just three US dealers. It wasn't possible that late in the production to abort the review. My apologies to the magazine's readers for this inadvertent exception to our rules.
For almost all of my tests, I drove the 5000 Signature D/A processor from…
Sidebar 4: JA Takes a Listen
It's hard to sum up the measured performance of the expensive four-box player. In many respects—its poor rejection of word-clock jitter, its nonflat response, its nonlinearity at low frequencies, its lack of ultrasonic image rejection, its higher-than-usual noise floor—it is the worst-measuring digital product I have encountered. Yet Michael Fremer was totally bowled over by its sound. Assuming Mikey is not deaf—and I have taken part in enough listening sessions with him to know that that is not the case—what the heck is going on with the Zanden pair? Is this…
Manufacturer's Comment
On behalf of Zanden Audio Systems, Ltd., I would like to express our gratitude to Mr. Fremer for the excellent review. The Model 5000 Signature DAC and 2000 Premium CD transport have been reviewed numerous times, and the response has just been tremendous. Without exception, every reviewer has been overwhelmingly positive. Among digital playback systems, the Zanden combo is something special and must be heard to be believed.
I would also like to apologize to Mr. Atkinson for having sent a unit with some faulty wiring. The 5000S DAC normally measures quite…