Mastersound 300 B S.E. integrated amplifier
Although she'll deny it, my wife thinks ill of me because I've failed to buy her a new Mini Cooper. I can point to a number of things in my defense—especially the Mini's lack of all-wheel drive, which we need for climbing our quarter-mile driveway in bad weather, and its insufficient cargo and passenger space—all of which would constrain a Dudley-owned Mini Cooper to recreational use only. And a new round of car payments would be difficult to justify for those reasons: not because I'm cheap, and not because I'm too old to appreciate a car that's fun to drive.
I admire the new Mini. Steeped as it is in the engineering tradition for which BMW, its new parent manufacturer, is rightly famous, the latest Mini has a torquey motor, a crisply precise shifter, a pleasant interior, and a very high level of fit and finish overall—none of which could be said about the Mini's earlier incarnations (footnote 1). That's because none of the manufacturers previously associated with the Mini seemed to think that building a very-high-quality version of the thing and pricing it accordingly would meet with success. And indeed, 40 years ago, that may have been true.
The thing is, the modern Mini is cut from the same cloth as virtually any modern single-ended amp, including the Mastersound 300 B S.E. integrated amplifier. The Mastersound's output architecture can trace its roots all the way back to the very first electric amplifiers, yet its implementation of that architecture is decidedly modern.
In truth, the sorts of single-ended-triode (SET) amplifiers that we know and love today could have existed when the passenger pigeon and Lee DeForest walked the earth. But back then, no one dared dream of a commercially (let alone domestically) acceptable product built with the huge, high-quality output transformers needed for full-range operation. In the years since, we've learned that audio enthusiasts are more willing than most to buy all sorts of crazy things; big, expensive amps are just the tip of the iceberg.
Mastersound, a family-owned company located near the Italian city of Vicenza, seems poised to take advantage of that shift in the consumer cosmos. Founder Cesare Sanavio, who built his first tube amplifier back in 1947, dedicated most of his professional life to the design and manufacture of very-high-quality audio-frequency transformers. His audio-enthusiast sons, Luciano and Lorenzo, witnessed the birth of the modern SET movement, and realized that they were in a uniquely good position to join the industry themselves: rather like developing an interest in making furniture, then discovering that your family owns a sawmill. Mastersound's first commercial amplifiers appeared in 1993, and the rest, as they say, is history.
Description
The Mastersound 300 B S.E. is a true integrated amplifier, with an active line-level preamplifier in front of its final (as they say in Italy) amplifier. The preamplifier uses both halves of a single 12AU7 dual-triode tube per channel, purely for voltage gain. The driver stage of the final amplifier comprises both halves of a 5687 dual-triode capacitively coupled to the 300B output triode, which itself is operated in cathode-bias mode. (I measured the rail voltage at a seemingly high 500V, but the cathode-bias arrangement considerably lessens the operating voltage actually seen across the tube.) The output tubes are heated with DC, evidenced by the 300 B S.E.'s absence of hum through my speakers: The only unwanted noise emitted by my review sample was a brief, soft buzz, audible only when the power-supply capacitors were charging up.
The build quality is superb, and strikingly reminiscent of the Lamm ML2.1 monoblock ($29,990/pair). Most of the parts reside on a single, large circuit board, with various other bits rigidly fastened to the chassis itself. In another Lammian touch, all transformers are thoroughly potted in epoxy, or something like it. Signal capacitors are mostly polypropylene types, evidently custom-made for Mastersound.
The front panel of the 300 B S.E. sports only two controls: a volume knob and a rotary selector switch, for choosing among the four line-level inputs. A fifth choice, labeled Direct, activates a pair of inputs that bypass the Mastersound's volume pot and line-level gain stage altogether, for use with an external line-out preamplifier. (Because the disappointing owner's manual doesn't say otherwise, I first assumed that Direct indicated a line-level input from which some unnecessary parts had been removed, and that I would hear something wonderful if I used those inputs for my CD player. My family was in the next room at the time; they're still angry with me for the deafening loudness that resulted.) Source input impedances are all specified as 100k ohms, while Mastersound claims that the inputs for the power amp are closer to 50k ohms.
The remote handset supplied with the 300 B S.E. is the height of simplicity and elegance. It functions only as a volume control, and sports just two buttons: one up, one down. There are no words, numbers, or markings of any sort—the two buttons are closer to one end than the other, so you can easily tell at a glance which one is up and which is down—and, best of all, it's carved from solid wood, with a light oil finish. If I were expecting visitors, especially female visitors, the Mastersound handset is the only one in the house that I would neither hide nor throw away.
I tried without success to remove the 300 B S.E.'s tube cage. For one thing, I was curious to hear if the Mastersound's audible performance would change with different output tubes. (I have other 300Bs on hand.) For another, experience tells me that some tube amps sound better with the tubes uncovered—although I'm darned if I know why. In any event, I failed, because I lack a screwdriver with a shaft sufficiently long and thin to reach the screw heads tucked inside the corners of the cage. Caveat tinkeror.
Installation
For the most part, I used the Mastersound 300 B S.E. in my main system, where it drove a pair of Audio Note AN-E SPe/HE loudspeakers. Most of that time was spent using the Mastersound as an integrated amp, driven only by a line-level source. I also devoted some listening time to using the 300 B S.E. as a power amp only, driven by my Shindo Masseto preamp (output impedance: 600 ohms) and fed by line-level and phono sources. Although the latter was more musically satisfying overall, the Mastersound's character remained the same in both arrangements.
I also tried using the Mastersound in the next room, with my Quad ESL speakers. But I did so only long enough to note that the zero-feedback 300 B S.E. was unsuitable for driving such a wiggy load: It just wasn't happening.
I tend to place integrated amplifiers much closer to my source components than to my speakers: either on a rigid oak table next to my turntable stand, or, in the case of very large or heavy amps, on the hardwood floor. Due to the Mastersound's extraordinary weight (73 lbs), the floor was the only realistic choice, and while I tried a couple of different isolation platforms between floor and amp, neither made more than a slight and quite possibly imagined difference. Speaker cables were a different matter altogether: My choices were limited to the few on hand that were long enough to reach from one end of my room to the other, and the Mastersound 300 B S.E. clearly sounded best through the copper Auditorium 23 cables.
Listening
In a general sense, the Mastersound's most apparent quality was its very wide bandwidth, especially for a tube amplifier operating in single-ended mode. That quality may indeed have stemmed from a superior approach to designing and making output transformers, although I doubt if such good performance could result from any single thing. Whatever the reason, the 300 B S.E. had an enjoyably open sound, with a better-than-average—if not the absolute best—degree of realistic detail and texture. To the consumer who fears that this old technology will make his records sound murky or lo-fi, the Mastersound 300 B S.E. will be a pleasant surprise.
In addition to simply sounding good, and in common with other high-quality SETs, the 300 B S.E. was musically expressive. Melodic and rhythmic nuances remained largely undistorted, and the amp's sense of flow was satisfying. Tonally, it was surprisingly uncolored overall: Hobbyists looking for a decidedly warm, sweet sound will be better served by other SET amps, while those who cherish tube amplification for other reasons, and who prize timbral neutrality above all else, will find much to enjoy in the 300 B S.E.'s performance.
Another surprise: Driving the Audio Note speakers, the Mastersound 300 B S.E. was a fine rock'n'roll amp. Both sonically and musically, it was an ideal partner for such fare as Etta James Rocks the House (LP, Chess CH-9184), a live recording from 1963 that captures the singer with an anonymous pickup band, playing for one of the most loudly receptive audiences I've heard on record. The surprisingly well-played electric bass on "Seven Day Fool"—sung with such abandon that it almost sounds as if James is saying, "On Tuesday, I'm gonna hurt you!"—had more depth and rhythmic nuance through my Shindo separates, but in every other way the Mastersound played this and other up-tempo records faultlessly, with real drive and momentum.
Turning to more introspective music, the Mastersound reproduced Pieter Wispelwey's recording of Tchaikovsky's Andante cantabile for Cello and Strings, Op.11, with Daniel Sepec and the German Chamber Philharmonic (SACD, Channel Classics CCS SA 16501), with nice tone and an above-average sense of flow in the melody carried by the solo cello. The sound was physically big overall, which I enjoyed, but it also sounded more reverberant than usual, and was slightly more forward than with my usual electronics, and with less spatial distinction between soloist and orchestra. Other recordings were reproduced with sufficient depth—such as the brushed snare way in the background of Leonard Cohen's "So Long, Marianne," from the recent remastering of Songs of Leonard Cohen (CD, Columbia/Legacy 88697 04742 2, footnote 2).
Other sorts of string tone were equally well served by the 300 B S.E., as on Dolly Parton's excellent Little Sparrow (CD, Sugar Hill SUG-CD3927). Through the very best gear I've used, the fiddles and fretted instruments on this modern-sounding CD have decent tone and surprisingly good texture—even the string bass, which sounds deep, quick, and appropriately woody through my Shindo separates. The Mastersound did almost as well: good low-frequency extension, but not quite as much color and texture.
In my experience, the sound of the selections from Schubert's Rosamunde recorded in 1960 by Stanislaw Skrowaczewski and the Minneapolis Symphony (LP, Mercury Living Presence SR90218) is distinctly system-dependent. On less sophisticated gear, the listener's attention is drawn to the excessively bright, in-your-face sound; but on the best gear, while the brightness and unrealistic perspective remain, the listener's attention is drawn instead to the sheer drive and bounce in the string playing, and the believable sound of the hall decay—especially following plucked notes. In that regard, the Mastersound's amp section, driven by my Shindo preamp, did a lovely job. The 300 B S.E. allowed this record to sound lively and tactile and, ultimately, satisfying.
The Mastersound 300 B S.E. is rated at 12Wpc—a bit optimistic for a standard 300B tube operated in class-A, though not beyond the capabilities of modern "high-performance" versions of that output triode—while my tetrode-based Shindo Cortese is said to provide 10Wpc. This made for as interesting a comparison under real-world conditions as it looks on paper. With the Audio Note AN-Es, the Mastersound was acceptably dramatic with most music—but, subjectively, it sounded less powerful than the Shindo amp, especially with recordings of massed voices, including the famous Kempe recording of Wagner's Lohengrin (LP, Angel 3641), and the finale of Gilbert Kaplan's first recording of Mahler's Symphony 2 (CD, MCA Classic MCAD 2-11011). Especially with the latter, while not sounding egregiously harsh, the Mastersound gave voices a brighter, ringing sort of sound that was less natural and listenable than the Shindo.
I try to stay mindful of the dangers of confusing a product's appearance with its sound, at least partly by keeping in mind those many products that confound the obvious patterns: small amps that sound big, light-colored amps that sound dark, etc. But the fact remains that the very large Mastersound 300 B S.E. also sounded consistently huge in my system—not in the sense of "throwing a big, billowy soundstage" (ugh), but in the sense that the amp had the same believable sense of scale with large music as it did with the small stuff. Which was good.
Conclusions
I hate tight shirts, astrology, scotch whisky, overcooked pork, publicity hounds, Ayn Rand, John Sayles, greedy shopkeepers, Queen, Las Vegas, and I Love Lucy. But more than any of those things, I hate background music. When I hear music, I want to give it all of my attention (unless it's Queen); when music is played as a background to something else—dining, drinking, talking, refueling my car, whatever—it only ticks me off.
The nicest thing I could say about a device intended for music playback is that it did a poor job with background music: I couldn't ignore it, so I either had to pay attention or switch it off. That has been true of literally every combination of low-power, single-ended tube amp and high-sensitivity loudspeaker I've had in my home so far. Whatever their relative frailties and strengths, they have all honored recorded music by making it unignorable.
The Mastersound 300 B S.E. integrated amp carried on that tradition, generously, and did so with style. It's among the highest-fidelity SET amps I've used, yet it filled that role without sacrificing all the good qualities that often seem to come from a different direction altogether—such as flow and momentum and the ability to sound human rather than mechanical.
The 300 B S.E. offers acceptable value for the money, especially to the hobbyist who already has a warmish-sounding system and wants the benefits of a single-ended triode without adding more color. It would be a fine thing to install once and enjoy, tweakless and serene. Recommended.