The Imagine B is very similar to PSB's Imagine T tower model, which Kalman Rubinson reviews elsewhere in this issue. The B uses just one of the T's reflex-loaded 5.25" woofers instead of two, but appears to have the same titanium-dome tweeter, so it should be very similar to the larger speaker in most respects. The B's voltage sensitivity was to specification, at 87dB(B)/2.83V/m, or 1dB below that of the Imagine T. The B's impedance with its port open (fig.1) dipped to 3.3 ohms in the lower midrange, with a combination of 5.1 ohms…
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What is it about a component that makes the blasé High Ender sit up and say, "Hey, this is special!"? What elements of its reproduction reach out to you and won't let go? How does the intrepid audio reviewer find a way to describe these hopefully recurring moments of musical discovery which define the high-end experience? How many times, after all, can you say, "Ooooo, ahhhhh, that's the best [insert some part of the frequency range here]," ad nauseam? How much difference is there, anyway? Therein lies the tale...
Our Lamm experience began auspiciously enough. The door buzzed. I…
Warmup time is a recommended 45 minutes, which I found right on the ruble—even though we left these guys running continuously (gulping their 300W idle current—oh well), to facilitate our hectic New York reviewing schedule. No whumps, bangs, or transients of any kind marred the performance of the amps. (Switch-off engages a special circuit which mutes the output.)
Both the power and the load selector switches employ a special mechanism which locks them securely into the chosen position. One pulls the actuator back to unlock the switch before moving it to the desired setting—just another…
Sidebar 1: Specifications
Description: Hybrid vacuum-tube/solid-state monoblock power amplifier with one 6922 tube and 12 output MOSFETs; switch-selectable bias/voltage settings for 1–6 or 6–8 ohm operation. Continuous output power: 100W into 8 ohms (20dBW); 100W into 4 ohms (17dBW); 200W into 2 ohms (17dBW); 300W into 1 ohm (15.7dBW). Frequency range: 4Hz–150kHz. Slew rate: 32V/µs. Damping factor: 40 into 8 ohms (constant from 20Hz–20kHz), equivalent to an output impedance of 0.2 ohms.
Dimensions: 20" D by 17" W by 8¼" H. Shipping weight: 91 lbs.
Serial numbers of units reviewed:…
Sidebar 2: Review context
The CAT SL-1 Signature was our system's supremely musical and neutral centerpiece. The big Avalon Ascent loudspeakers and their separate crossovers now sit regally upon two ¾" MDF panels measuring 10½' by 4'. These panels are glued, much-screwed, and bolted to the plywood floor beneath—and as often as possible into passing structural beams. With everything up on Audiopoints, the bennies were as expected: tighter, deeper and more controlled bass (especially with the Lamms), an airier and considerably more open soundstage, better focus, and important gains in the…
Sidebar 3: Measurements
A full set of measurements of the Lamm M1.1 was made in the unbalanced mode. I also checked the input impedance, gain, signal/noise, frequency response, and THD vs frequency in the balanced mode. All of the 8 ohm measurements were made with the impedance switch in the 6–8 ohm setting; the 2 and 4 ohm readings were made in the 1–6 ohm position, except as noted otherwise. Following the 1/3-power, one-hour preconditioning test, the M1.1's heatsinks were very warm, but I could touch them comfortably for an extended period without experiencing discomfort.
The…
There is an old hi-fi joke that goes thus:
First audiophile: "I hear Joe died."
Second audiophile: "I didn't know that. What did he have?"
First audiophile: "Oh, Marantz, Linn, Krell, Vandersteen."
This, was in effect, the information gleaned from Stereophile's readership survey forms returned last summer. Question 18 on the form, which was published in June 1988, asked readers to list their components and rate each one on the following basis: "Yes, I would buy again," "Maybe, I don't have an opinion," and "No, not if you paid me." We had hoped that an analysis of…
The No.331 is the latest iteration in a series of Mark Levinson 100Wpc, solid-state, stereo power amplifiers. Extensive cosmetic alterations, internal structural changes, and new circuit designs make it quite different from the No.27 and No.27.5 models that preceded it. These design refinements emanate from Madrigal Audio Laboratories' latest flagship amplifier, the $32,000/pair, 300W RMS Mark Levinson No.33 Reference.
The earlier No.20-series Mark Levinson stereo amplifiers were based on the company's former Reference monoblock, the $14,950/pair 100W RMS No.20 amplifier, first…
The '331's rear panel features four custom-made, gold-plated, high-current speaker-cable binding posts per channel in two columns, one for each channel, with two positive and two negative terminals in alternating fashion to allow for biwiring. These binding posts are the same 100-ampere–rated posts used on the No.33 Reference amplifier. This insulated connector satisfies the IEC-65 safety standard. The connector has a large curved wing nut. Using these posts, I was able to achieve tight, high-contact pressure connections with only modest finger pressure, and did not need my usual set of…
The '331's build quality is superb, better than I've seen in almost all other audio products. If weight, shielding, and size of heatsinks mean anything, then the No.331 should run much longer and more reliably than the No.27, which already has seen five years of steady, unbroken service in my listening room.
Sound: neutrality & transparency
Driving the Quad ESL-63s, the No.331 had stiff competition—my well-broken-in No.27 from the same manufacturer. I'd grown accustomed to this amplifier's treble detailing, which brought out the upper range of my Quad ESL-63s. With the No.27…