The Absolute Sound of Bass
Before getting into the terminology describing LF imperfections, let's consider the characteristics of ideal ("perfect") bass reproduction. These are: Balance: The amount of low-frequency output relative to the output through the rest of the audio spectrum.
Wide Range: Extending into the deep-bass region---and the deeper, the better. (Note here that a system will actually tend to sound as if it has greater LF range than its measurement would indicate.) Also called "Extension."
Smoothness: Freedom from audible dips and peaks in frequency…
Bass Instruments & Frequencies: John Atkinson
To tie the subjective frequency ranges to real music, these are the range of fundamental frequencies produced by typical bass instruments (footnote 1) (including the contrabassoon played by Stereophile contributor Lewis Lipnick). Note that, with the exception of the organ and the bass drum, musical instruments do not produce significant energy in the low-bass region. Why, then, is it important for loudspeakers to have response below 40Hz? The answer is twofold. As discussed above, the recorded hall ambience will have energy extending…
It's hard to know what the best strategy is for digital upgrades. Maybe you bought your first CD player when you became convinced that the format was going to succeed, and it seemed that players were about as good as they were going to get. Some time later, you tried one of the new outboard digital processors, and the sonic improvement was such that you just had to have it. Then you replaced the player itself with a CD transport, so you could benefit from improvements in servo control and digital output circuitry. At this point you were generally happy with your digital front-end—until you…
Sound
Bel Canto is best known for single-ended-triode tube electronics (including the SETi40, a Sam Tellig fave), and despite the fact that there are no thermionic tubes to be found anywhere in the DAC 1, this heritage was apparent in the sound. "Smooth," "musical," "non-fatiguing," and, yes, "analog-like" were some of the descriptors that came to mind. I know that some audiophiles are still inclined to characterize CD playback as harsh, edgy, and clinical, and I've certainly heard these sorts of sounds from digital front-ends in the past—but I don't see how any fair-minded person can…
Sidebar 1: Specifications
Description: Single-box D/A processor. Inputs: 1 S/PDIF RCA coaxial, 1 TosLink optical. Input sample rates: 32-96kHz. Bit depth: 16-24. S/N ratio: 112dB, A-weighted. Dynamic range: 112dB. THD: <0.003%. Frequency response: 0Hz–48kHz, -3dB. Analog outputs: 1 pair RCA. Output impedance: 50 ohms. Maximum output level: 2V RMS.
Dimensions: 3.6" W by 3.6" H by 9" D. Weight: 4 lbs.
Serial numbers of units reviewed: D001098A, D002078A.
Price: $1295 (2000); no longer available (2004). Approximate number of dealers: 35.
Manufacturer: Bel Canto Design, 212…
Sidebar 2: Associated Equipment
Digital sources: PS Audio Lambda II transport, MSB Link DAC III digital processor (with upsampler board, Full Nelson option, P1000 power supply), Rotel RCD-991 CD player.
Preamplifier: Convergent Audio Technology SL-1 Ultimate.
Power amplifiers: Cary CAD-2A3SE monoblocks.
Loudspeakers: Avantgarde Acoustic Uno Series Two.
Cables: Digital: Illuminati Orchid, Kimber Illuminations D-60. Interconnect: Nordost Quattro Fil. Speaker: Nordost S.P.M. Reference. AC: TARA Labs Decade.
Accessories: Argent RoomLenses (4), PS Audio P-300 AC synthesizer (…
Sidebar 3: Measurements
I performed all my measurements on the second sample of the Bel Canto processor (S/N D002078A). The processor successfully locked onto datastreams with sample rates between 44.1kHz and 96kHz, though it ignored a 32kHz feed. It seemed very prone to picking up RF interference when fed an electrical S/PDIF datastream, so, except where noted, I drove it using an AudioQuest TosLink datalink.
Maximum output was a hair higher than the "Red Book" standard at 2.09V RMS, while the absolute phase was correct with the front-panel button pushed in. Output impedance…
"As I was saying before I was interrupted..."—Jack Paar, 1918-2004
Lots of amplifiers come through these doors, and most of them have one thing in common: They're heavier than the boxes meant to contain them. A lot heavier. In fact, at least half the cartons I see in this line of work couldn't last more than two or three trips before giving way to their weighty contents—rather like the seats of some audiophiles' dungarees.
By contrast, a DNM 3-C preamplifier weighs nine times less than the simple yet nicely made wooden crate that contains it—and which, as I observed in last month…
Things I liked least: The DNM system had a heroically smooth yet precise sound that was beguiling on most music but wasn't a perfect fit for everything. It loved Joan Baez, Doc Watson, Eno's brilliant, early solo albums (such as Here Come the Warm Jets, a perennial Mikey fave), Purcell, Scarlatti, Schütz, all of Beethoven's and Schubert's and Brahms's music (even the symphonies), and a great deal more. But Russian music? Very early Roxy? The Replacements? The DNM rig was never quite as big and coarse and melodramatic as I wanted it to be. But I'm open to the suggestion that power-supply…
Art Dudley returned to the DNMs in March 2005 (Vol.28 No.3):
Unconventional audio products have almost always attracted me, few more than the DNM electronics I wrote about in my "Listening" columns of April and May 2004 (Vol.27 Nos.4 & 5). The DNM 3C Primus preamplifier and PA3-S amplifier are, in fact, the closest I've found to a complete rethink of what audio amplification ought to be, in materials as well as design, being, as they are, the sum total of everything that Denis N. Morecroft has discovered over the years about low-voltage music signals.
But is odder always…
