Mesa Engineering Baron power amplifier Page 2
That's because the Baron employs a separate duo and quartet of output tubes for each channel, and you can configure the amp so you alternate between class-A triode (at around 60W) or class-AB pentode (at 150W). Most significant, you can employ increments of the two operating modes: either 2/3-triode/1/3-pentode (at around 90W) or 2/3-pentode/1/3-triode at (at 120W), with three increments of negative feedback (or none at all). As a result, you can literally tune this amplifier disc by disc, song by song to best suit a particular recording style or volume level—while the music is on—or to tailor the amp's performance to accommodate different speaker types or room environments.
My speakers are very sensitive, and the 10" Focal bass drivers don't really require much damping, so we generally didn't employ any negative feedback (more on that later). We listened to the Emmylou Harris and a wonderful acoustic duet by Ray Brown and Duke Ellington, This One's for Blanton (Pablo PACD 2310-721-2), which has great room sound, amazing presence, and a lovely low end—and I was aerobicizing myself jumping up and down to switch back and forth between the modes to hear what the tradeoffs were. My wife voted for class-A triode because "It's gentler," and it's hard to beat all-triode for solo instruments, acoustic jazz, and chamber music. There was more air, a broader soundstage, greater separation and distinction between the instruments—it was just a sweeter, more involving listening experience.
Next we listened to a lovely Béla Fleck recording called Tales from the Acoustic Planet (Warner Bros. 45854-2). On a trio rendition of "Arkansas Traveler," Béla's banjo was crisp and sparkling, Edgar Meyer's huge double-bass had resounding presence, and we heard all sorts of pitch manipulations and timbral subtleties in Kenny Malone's brush work and bass drum. Then, on "Backwoods Galaxy" (the next cut, with Chick Corea, Branford Marsalis, and the Wooten brothers), Victor Wooten's electric bass didn't really seem all that present compared to the acoustic bass fiddle on the previous cut, so I switched to 2/3-triode/1/3-pentode and then to 2/3-pentode/1/3-triode. What was really interesting was not just that the bass was more present, but that the actual placement of the instruments began to change. All of a sudden the bass's actual place in the mix became a little more forward, a little more present, and a little more centered in the soundstage.
The soundstage itself was no longer quite as deep, and in exchange for more punch and presence, there was a slight loss in separation and transparency, but not until one turned to full pentode did acoustic sounds begin to harden, sounding as if they were coming through a P.A. If we were living in a huge loft or had very inefficient speakers, then full pentode would make some sense. But in a 12' by 20' space it's tantamount to having a hurricane in your living room—it's simply overkill (although when I first heard full pentode in Mesa's suite at HI-FI '96, it seemed like the most dynamic sound, at polite trade show volume).
As you can imagine, the variables and combinations are limitless. Late at night, when I'm not listening at concert-stage volume, adding increments of pentode power gives the music an appealing sense of liveness and presence. But at my normal listening levels, which are fairly loud, I mostly employ all-triode; at 2/3-triode/1/3-pentode, I seemed to move closer to the stage; at 2/3-pentode/1/3-triode the stage seemed to move closer to me. In listening to modern jazz recordings (like Kenny Garrett's Pursuance) or vintage analog symphonic recordings (such as Bruno Walter's version of Mahler's Symphony 9 or Herbert von Karajan's version of Brahms's Symphony 1) I found myself favoring 2/3-triode/1/3-pentode at more moderate volume levels—which seemed to give the orchestra a little more bottom and presence, without blurring delicate details or sucking all the air out of the room.
But when listening to rock, funk, or electric jazz—contemporary music employing contemporary recording styles, featuring unnatural frequency extremes, where you need fast, massive bursts of power to handle the transients, and the sense of venue is much less decisive—then 2/3-pentode/1/3-triode was the configuration I preferred. It really brought out the larger-than-life qualities in audiophile-class pop recordings such as Wrecking Ball, Little Village, and Turbulent Indigo, electric worldbeat like Jean Luc Ponty's Tchokola, and contemporary jazz like George Benson's That's Right.
And as a stone analog recidivist, I find that on pure digital recordings triode sounds relatively flat and lifeless. In listening to Bob Katz's recording of Oregon's Beyond Words (Chesky JD130), and Mark Levinson's recording of The Carnegie Hall Jazz Band (Blue Note CDP 36728 2), 2/3-pentode/1/3-triode conveyed extra dimensionality and transient impact. On Yoel Levi's Telarc recording of The Rite of Spring, the Baron translated Stravinsky's timpani strokes into big, soft cannonballs of love that leaped out of the speakers and crushed my sternum without mussing my hair.
I only employ full pentode when I'm feeling very frisky or my neighbors are having a party and I choose to up the ante. On King Crimson's live-to-DAT soundboard recording THRaKattak and Sly And Robbie's digital hip-hop anthem Silent Assassin (with KRS-One), the frequency extremes were so wild, the transients so monstrous, I employed negative feedback to tame and localize the bass, even-out the image, and make the highs more distinct. The Baron's three stages of negative feedback seemed to enhance the musical smoothness and focus, but at the expense of some transparency and imaging. But on music such as this, recorded at nosebleed volume levels, where the goal is not to capture room acoustics but to deliver a visceral impact, it's a big help. Stage one of negative feedback in the 2/3-triode/1/3-pentode or 2/3-pentode/1/3-triode modes is very subtle and musical, as I discovered after I listened to a number of recordings without realizing I'd left it on.
But generally, the only time I use negative feedback is when I'm really blasting away on vinyl—the reduced damping factor does help tighten up the bass. In listening to Wilhelm Furtw;dangler conducting Brahms's Symphony 1 (an epic 1952 Deutsche Grammophon treatment that stands shoulder-to-shoulder with Toscanini's legendary RCA Victor 1951 recording), two stages of negative feedback really helped clean up and focus the timpani accents Furtwängler employs to supercharge the giddy accelerandos at the climax of the fourth movement.
As you may have gathered, the Mesa Baron has significantly enhanced my life and listening environment. I leave it to such aural elders as John Atkinson and Wes Phillips to draw a definitive conclusion as to the Mesa Baron's rightful place in the hierarchy of great power amplifiers. But for this aural pilgrim, the Mesa Baron is the truth, the whole truth, and nothing but the truth. Tandem State Imaging is a source of endless fascination, and I'm finally able to experience recorded music at a level of dimensionality and impact heretofore reserved only for audio salon listening rooms, concert halls, and wealthy high-end enthusiasts.
I wonder what the preamp will be like.—Chip Stern