Description: Solid-state stereo or mono amplifier. Power output: 60Wpc into 8 ohms, >40Wpv into 16 ohms, both channels driven, 20Hz–20kHz; in mono mode, >100W into 8 ohms, >120W into 14 ohms, 20Hz–20kHz. IM distortion: <0.2% at rated output; <0,1% at lower levels. THD: <0.2% at rated output, <0.05% at lower levels. Frequency response: 20Hz–20kHz ±0.1dB; 3Hz–100kHz +0, –2dB. Power bandwidth: 8Hz–50kHz. Hum & noise: >110dB below 40 watts. Damping factor: >150. Stability: Unconditional with any type of load, or no load. Sensitivity: 1.…
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In writing for magazines, there's a basic rule: Don't become the subject. And in writing about the arts, it's best to remember that you aren't in the music business or the film business: you're in the publishing business. Despite this, there are arts writers who fancy they're a part of the world they write about. All famous musicians are their "friends." The music business values their opinions. They're caught up in the delusion that the Rolling Stones sang about so deliciously in "Star Star," the closing number on Goats Head Soup.
At the risk of breaking that rule, I must note that…
Editor's Note: Approaching its ninth year of publication in 1970, the advertisement-free Stereophile was failing as a business. There was just one issue published between December 1968 and June 1970, the date when J. Gordon Holt published this plea in response to the reaction to the increased subscription price: first to $4 for four issues, equivalent to $25 in 2016, then to $5 ($31). The response from subscribers to his plea was not positive enough to enable the magazine to continue publishing—Gordon could publish just two more issues in the next two years before Stereophile had to accept…
Boy, do we ever get letters. From readers angry that we review too many expensive products. From readers depressed that we review too many affordable products. From readers bemoaning our digital coverage. From readers asking when we're going to get with the 21st century and stop gushing over analog. From readers wanting more coverage of tube products. From readers wanting more coverage of MOSFET amplifiers designed for high voltage gain on the output stage.
Well, okay, we've never received the last type of letter. But if we did, it would have to refer to Hafler's new Transnova 9500…
The brightness I noted with the WATT/Puppies was nowhere in evidence here. On Behold Man, another selection on this sampler, this time of solo chorus (from Testament, RR-49CD), the overall balance was excellent, with no sense of brightness or leanness but rather compellingly natural warmth and acoustic space. The latter is particularly notable throughout this CD, and the Hafler did an especially good job of reproducing it. Likewise in the portrayal of depth, where the front-to-back layers of the chorus were clearly audible.
Nor did the 9500 shortchange other types of program material.…
Sidebar 1: Relax and float downstream...
The Transnova idea is conceptually elegant and not dissimilar to a push-pull tube output stage. In a conventional output stage (diagram A), the "positive" or "hot" load terminal is connected to the junction between the emitters or sources of the complementary output transistors and the ground load terminal to the junction between the ±V reservoir capacitors. In general, this point defines the ground potential or 0V and is used as the amplifier's fundamental or "star" grounding reference. The output devices therefore act as emitter or source…
Sidebar 2: Associated equipment
The Hafler was auditioned with a variety of loudspeakers, but I spent most of my listening time with it in the company of the Vandersteen 2Ces. The preamp was the Rowland Consummate. Comparison amplifiers included the Aragon 4004 Mk.II, Sonic Frontiers SFS-80, and Krell KSA-250.
The CD transport was either the belt-drive C.E.C. imported by Parasound or the Pioneer Elite PD-65 used as a transport (the latter used primarily when the Wilson WATT/Puppies or the Apogee Stages were in the system), used to drive a PS Audio Ultralink via Kimber AGDL. The…
Sidebar 3: Measurements
The Hafler 9500's input impedance measured just over 47k ohms. Gain into 8 ohms was 28dB. The output impedance was very low, ranging between 0.016 ohms and 0.022 ohms depending on frequency and load. This suggests a very consistent performance with a wide range of loudspeaker loads. DC offset measured 6.8mV in the left channel, 13.6mV in the right. S/N (unweighted at 1W into 8 ohms) measured 92.7dB. The 9500 was noninverting, a positive impulse at the input remaining positive at the output.
Fig.1 shows the frequency response of the 9500 at 2W into 4 ohms.…
Sidebar 3: Specifications
Description: Solid-state, two-channel power amplifier. Power output: 250Wpc (8 ohms) (24dBW); 750W (8 ohms) (28.75dBW) in bridged dual-mono mode. Full power bandwidth: 0.15Hz–300kHz. THD: <0.03%, full power, 20Hz–20kHz into 8 ohms. Sensitivity: 1.8V RMS for full power. Input impedance: 47k ohms. S/N ratio: >100dB, unweighted.
Dimensions: 19" W by 12.5" D by 5.25" H (excluding feet, rack-mount version). Weight: 50 lbs.
Serial number of unit tested: D16C121000120.
Price: $1900 (black), $2000 (silver), rack handles $70 (option with black, standard…
The year was 2116, and the Earth was finally great again.
War, poverty, global warming, starvation, racial inequality—these, among many others, were all trivial, long overcome matters of the past.
Generation ZZZZers glided around in auto-piloted, eco-friendly, space/time ships. They communicated with each other via holographic telekinetic mind messages. (Though there was always the occasional hippie, of course, who'd pull out a vintage, non-functioning wePhone 2000 or whatever technological dinosaur was making a comeback these days. Lame, if you ask me.)
Televisions were…