Measurements
As Wes Phillips found, the Linn Linto was astonishingly quiet, with an A-weighted S/N ratio (ref. 500uV input at 1kHz) of 85.3dB. Unweighted, with a broad measurement bandwidth of 10Hz to 500kHz, the S/N ratio dropped to 66.5dB, which is still excellent. Its voltage gain in the high setting (the only one I measured) was 62dB rather than the specified 64dB, probably due to the 25 ohm source impedance of the Audio Precision System One. The difference is negligible. The input impedance measured 165 ohms at 1kHz, slightly higher than spec, while the output impedance was a low…
I had a wonderful audio moment the other night. It was late in the evening, after a long day. I was standing in the middle of my makeshift listening room—Trish's dining room—and in spite of the fact that we were moving in just a few weeks, I'd just unpacked and set up my combo of VPI TNT Mk.V-HR turntable and tonearm with Grado Statement cartridge and dug a box of LPs out of the stacks in the garage. I cued up Dave Brubeck's Time Out (Columbia/Classic CS 8192), and the first notes of "Blue Rondo à la Turk" froze me in my tracks.
The music hadn't just started, it had come to life…
The Signature looks gorgeous. Its faceplate is a thick, softly sculpted slab of aluminum finished in a flawless, glossy black embedded with gold flecks that beautifully complement the heavy, gold-plated knobs. There are large knobs for Input Selection and Volume, flanked by two smaller ones on each end: Mute and On/Off on the right, Tape Monitor and Cinema/Direct on the left. The Cinema input provides a fixed-gain path from input to output, allowing a user to send the front channels of a home theater or surround system through the main audio circuit, but controlling the level with a…
Midway through the Saint-Saëns Bacchanale is a delicate exchange between the woodwinds and French horn. With the VAC, it wasn't simply point/counterpoint, but more like a tennis match, the lines bouncing back and forth between the instruments, their location and interaction with the surrounding space and hall boundaries transcribing an arc through the air above the orchestra. This particular passage was especially captivating because the span so beautifully described was truly three-dimensional, traveling not only laterally but also front to back and vertically, describing the relative…
Sidebar 1: Specifications Description: Two-chassis, remote-controlled tubed preamplifier with optional integral phono stage. Tube complement: two 12AU7, two 8416 (line stage), six 12AX7 (phono stage). Inputs: 4 sets RCA line, 1 set balanced XLR line, 1 MM/MC phono (or additional RCA line), 1 set RCA tape monitor, 1 set RCA home theater "direct input." Outputs: 2 sets RCA main out, 1 set balanced XLR main out (pin 2 "hot"), 1 set RCA tape record out. Voltage gain: 12dB line, 44dB MM phono, 64dB MC phono. Polarity: noninverting.
Dimensions: 18" (203mm) W by 5.5" (140mm) H by 14.5" (…
Sidebar 2: Associated Equipment Analog source: VPI TNT Mk.V-HR turntable/tonearm; Grado Statement, Benz Micro L04 cartridges.
Digital sources: GamuT and Simaudio Moon Eclipse CD players.
Power amplifiers: VAC Renaissance 70/70, VTL Ichiban, GamuT D-200.
Loudspeakers: Magnepan MG3.6/R.
Cables: Interconnect: Nirvana S-X Ltd., Nordost Valhalla, AudioQuest Anaconda. Speaker: Nirvana SL, Nordost, AudioQuest Gibraltar. AC: Synergistic Research, Reference Master Couplers.
Accessories: Merrill equipment stand; Bright Star Big Rock, Little Rock, and Air Mass isolation devices;…
Sidebar 3: Measurements I first looked at the VAC Renaissance Signature Mk.II's phono stage, taking the output signal from the tape-out jacks. The input impedance and voltage gain at 1kHz were 47k ohms and 43.7dB (MM setting) and 365 ohms and 64dB (MC). The RIAA error, shown in fig.1, is distinguished by a double-humped response curve with an upper-midrange valley some 0.5dB deep. This covers a wide enough frequency range to be audible. The response is sensibly curtailed above and below the audioband, reaching -3dB ref. 1kHz at 11Hz and 76kHz. Channel separation (fig.2) is good rather…
Fig.8 shows the spectrum of a balanced 50Hz sinewave signal at 2V, about the maximum level the preamp will be required to deliver to the partnering power amplifier. Odd-order harmonics typical of transformer saturation are evident, with the third harmonic visible just below -50dB (0.3%)—but so are even-order harmonics. The second harmonic, for example, lies at -54dB (0.2%). As anticipated from the THD curves, the distortion spectrum at higher frequencies (fig.9) is significantly cleaner. Though the third harmonic is still the highest in level, it now lies at almost -70dB (0.03%).
… Let's talk cable dressing. Make mine vinaigrette! (And you thought I'd go for French . . . ) Cable dressing is actually a rather delicate issue that requires a certain leap of faith. The concept is so simple that even I can explain the science to you. But the leap occurs when you realize how the positioning of cables and interconnect can make a real difference in the sound of your system. In spite of this, I've seen power cords and interconnects tangled up in a hopeless mess at the back of some pretty serious components. The mechanical universe tells us that a signal flowing through a…
"A field has a point of origin, but that's it. What's important is not that the field extends to infinity but that it extends beyond the cable itself. In fact, there's good evidence that it's not the electrons that carry the signal, but the electric field around the cable that does. You see what this means? If the field is affected by the dielectric and everything is the dielectric, then everything affects the sound of the cable. That's where the inverse square law comes in. The relative effect of the dielectric depends on the distance. It's only what lies an inch or two from the cable that…
