The Carver Lightstar Reference is a power amplifier whose ratings suggest that it is an ideal voltage source—meaning that its rated power doubles with each halving of load impedance (300W into 8 ohms, 600W into 4 ohms, 1200W into 2 ohms). That's difficult to accomplish with conventional power transistors, which operate safely only within a restricted range of voltage/current combinations. (The graph of this range is called the transistor's safe operating area.) Many amplifiers deal with this limitation by using several transistors…
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Sidebar 2: Carver Research Lightstar Reference: Design
Sidebar 3: Review System
Analog sources were the Linn Sondek LP12 with all the accoutrements (Lingo, Cirkus, QR/DNM Design 330 Mk.II Ringmat), Linn Ittok, and AudioQuest AQ7000nsx. Digital sources were PS Audio's Lambda transport, Sonic Frontiers' UltraJitterbug, PS Audio's UltraLink II, and Sonic Frontiers' SFD-2. The preamp used was mostly a Sonic Frontiers SFL-2, with some use also made of a Convergent Audio Technology SL-1 Signature. Reference power amplifiers were the Bryston 7B monoblocks, Krell KSA-100S, and Threshold T-200.
Interconnects, digital links (AES/EBU), and…
Sidebar 3: Measurements
A full set of measurements of the Carver Lightstar was made in its unbalanced mode, with selected measurements repeated for the balanced configuration. Unless otherwise noted, the results below are for unbalanced operation. Also, all measurements (except for the gain check) were made with the normal gain setting.
Following the 1/3-power, one-hour preconditioning test, the Lightstar's heatsink/chassis was too hot to touch comfortably for more than a few seconds.
The Lightstar is non-inverting in the unbalanced mode. Balanced, pin 2 is configured as…
Sidebar 4: Specifications
Description: Solid-state stereo power amplifier. Power output: 300W into 8 ohms (24.8dBW), 600W into 4 ohms (24.8dBW), 1200W into 2 ohms (24.8dBW). Frequency response: 20Hz–20kHz ±0.5dB. Full power bandwidth: 10Hz–20kHz. Channel separation: >60dB at 1kHz. Output impedance: ±0.04 ohms. Damping factor: >200, equivalent to an output impedance of less than 0.04 ohms. THD: <0.2%. Signal/noise ratio: low gain, 107dB; high gain, 98dB (A-weighted, referenced to rated power); low gain, 82dB; high gain, 73dB (A-weighted, referenced to 1W). Slew rate: >50V/µs.…
For a major, decidedly American change of pace from our usual fare of Prokofiev, Debussy, Xenakis, Berg, and Beethoven (for starters), let's lighten up with Reference Recordings' latest hybrid SACD, John Williams at the Movies? Also available as a 176.4/24 download—the format in which it was recorded and which I auditioned for this review—the performances by the Dallas Wind Band under Jerry Junkin are so vivid and color-saturated that RR has chosen them for their first hybrid high-resolution wind-band SACD.
The first thing you'll hear is that the team of Keith O. Johnson and Sean Royce…
Okay, we know that Humphrey Bogart didn't utter that immortal instruction in Casablanca, but we couldn't resist, given that this issue includes Jim Austin's adventures with Apple's HomePod, the first smart speaker with hi-fi pretensions, which is featured on our August issue's cover.
But wait, there's more! Reviews of ultimate power amplifiers from Pass Labs and Moon by Simaudio; an unusual but high-performing speaker from Tekton; Roon's fit'n'forget Nucleus+ server; a high-performance turntable from Merrill-Williams; and Herb Reichert comparing AC cords. (Yes, we know, that way madness…
Tchaikovsky: Swan Lake & Sleeping Beauty Selections
New Philharmonia Orchestra, Stokowsky
London Phase-4 SPC 21008 (LP); Ampex LCL-75008 (open-reel tape). Tony D'Amato, Marty Wargo, prods.; Arthur Lilley, eng. TT: 46:50.
New Philharmonia Orchestra, Stokowsky
London Phase-4 SPC 21008 (LP); Ampex LCL-75008 (open-reel tape). Tony D'Amato, Marty Wargo, prods.; Arthur Lilley, eng. TT: 46:50.
These are exciting, lilting, concert-style (as opposed to ballet-style) performances of the best-known excerpts from Tchaikovsky's second- and third-most-popular ballets. (First, of course, is the Nutcracker.) The recording is a surprise, after the excesses we've heard on earlier Phase-4 recordings. Gone are the screaming highs, the room-rocking bass boom,…
The men behind HDCD (L–R: Pflash Pflaumer, Michael Ritter, Keith Johnson
High Definition Compatible Digital® (HDCD®), the proprietary process for improving the sound of 16-bit digital audio, has finally arrived. More than a dozen digital processors using the technology are on the market, and the professional encoder used to master HDCD discs is following closely behind.
Anyone who has followed my writings on HDCD (including the review of the Spectral SDR-2000 Pro processor in this issue) knows how enthusiastic I am about the sound quality offered by this new technology. I believe…
You therefore had to draw a line and say you've got a 40dB-dynamic-range system; I can't use the stuff that's below that. The problem is made worse if there's a good rim shot on a drum or a cymbal crash. A peak level on an orchestral session can be 110–120dB. The analog tape will saturate, but it only happens during a brief moment in time. You're not aware that it has happened, but a digital system will go crazy if you overdrive it. After the peak, you're back in the soft passages below the 40dB range where things don't work well.
The very thing the digital systems were touted as being…
Pflaumer: That's true. In the human ear, the cochlea has hair cells that respond to about 80kHz. And yet, for steady-state
sinewaves, even a young person can hear only 20kHz as a steady-state tone. As we get older, that deteriorates. But the sense of frequency extension is largely based on transient events—things that happen only in short instants of time.
The shape of a wavefront generates harmonics in the bone structure of the middle ear, which are then picked up by the hair cells in the cochlea and used to reconstruct the picture of that wavefront.
The army did quite a lot…