There’s something about Mary Halvorson. Is there a more daring jazz musician today? Queen of geek chic, words creak under the strain of classifying her sound. ‘Fluid atonalism’ comes to mind but such an oxymoronic term does no justice to this avantgarde guitarist. This is the reaction some of us always hoped for but never felt whilst listening to Ornette Coleman. Halvorson seems to be more complex and decidedly impish too. She records with a wide variety of players in duo and trio formats all the way up to the septet. Like Ornette, Mary’s contrary but not for the sake of contrariness. Her Thumbscrew Trio is to me the most exciting thing in jazz since Tord Gustavsen emerged as a leader a bit over a decade ago. Halvorson’s playing is diametrically opposed to Gustavsen. Where he is romantically reverberant, unabashedly lyrical and prone to elide his phrasing, she is still fluid but more angular, muscular and at times disjointed. He’s Leffe Blonde, she’s Chimay. With a little patience, you might find an inner logic to her work—with galloping scales squeezed between snippets of skronk—that you might not find in Coleman’s whine and screech. Less philosophical about these matters, my wife considers Halvorson’s music to be "demented", full stop.

Perhaps therein lies her genius. As I listened to "Still…Doesn’t Swing" from Thumbscrew, I sat riveted to my chair. Two-thirds of the way through the track, Halvorson takes a manic run up the fret board only to resolve the musical conundrum she has created with a sort of musical joke, deflating the tension she has built in a slow unwinding prickling process that elicited rip-roaring laughter the first time I heard it. If Jazz’s singular appeal lies in its ability to tease and surprise, then Halvorson is the poster girl for that notion. The Turbo has got the speed, the PRaT, the ability to soak my listening room with Halvorson’s weird tones. It’s that sense of fully developed overtones, of propulsion, of elastic and fluid images leaping out with astonishing speed and then retreating just as fast, that’s so enthralling. And it’s all so effortless with those coke-can capacitors coiled up and ready to pounce. I’ve never heard guitar sound so good in my house. And so up the volume went. My Audio Research/W4S SX-1000s are far more powerful but can’t even get me halfway there. Only the Turbo let me set my controls for the heart of the sun without blurring the music’s vision and causing my ears to bleed.

Think of the high-definition films recently posted on newspaper websites capturing the activity of one of the largest sun spots to appear in decades. And pray to the audio gods that we never live to see our expensive audio equipment fried by a solar storm on the order of 1859’s Carrington Event. No surge bar is going to protect us. Like mass coronal ejecta, Halvorson’s notes lept forth until the unbearable heaviness of gravity pulled them back. Before there was time to revel in the delicious decay, out popped another loopy note. An acquired taste perhaps, but you won’t be able to drink up without a great amplifier like the Turbo. The wonderful Psvane TC5 I have on review for another site will keep up with Halvorson’s manic pace but won’t simultaneously keep focused on inner detail. My Line Magnetic 518IA keeps pace but seems to render Halvorson in a more polite fashion with a bit less detail. The Psvane TC5 is a KT120-based push-pull amp weighing in at 25kg and currently selling for $1’399 (plus import duties). If the Psvane had a readily pronounced name that did not originate in a typographical error; and if it had a clear brand identity promoted by a wide retail distribution network… it might knock Primaluna off its pedestal. As a two-time Primaluna owner, I believe the Psvane is that good. But the Turbo is so much better! With Halvorson’s music, the TC5 shoots straight down the middle in a tight focused way whereas the Turbo gives a wide-angle three-dimensional view. With the TC5 you’re trailing the notes like a storm-chaser; not quite there. With the Turbo you’re in the eye of the storm to see the whole picture lit from within. The TC5 might be more accurate or it might not be but it seems to be truncating the notes, not letting them bloom and breathe and decay. It’s a great amp but not as full and warm as the Turbo, hence less interesting to me.

Listening to Halvorson batters your senses. More readers will relate to the comparatively straight-ahead Keith Jarrett Standards Trio featuring his long-time buddies Jack DeJohnette and Gary Peacock. The Turbo seemed to capture more of the warm glow of Keith Jarrett’s piano on "How Deep is the Ocean" [Live at the Blue Note disc 4] than my Audio Research LS17/Wyred4Sound SX-1000 system could. The Turbo reminded me of the depth and warmth a sadly departed 300B-based Musical Paradise amp had imparted to piano. It also brought back memories of a great Naim system I once owned consisting of the 200/202/NAPSC/HiCap2. Jack DeJohnette’s cymbal strikes shimmer and shine but they should have weight and body too. Transients were almost Naim-like but with body. That lack of body was precisely what made me leave the flat-earth sound behind. By contrast the Turbo is a great all-rounder.

Psvane versus Coincident

Like a thoroughbred, Keith Jarrett is hard to handle. One never knows which persona will show up. Will he lecture and hector his audience in the wake of that crime of crimes—the human cough—or give of his body and soul? Will he phone it in and go away with no word of farewell as he did in Toronto a few years ago? No matter, there’s no longer any need to see him in concert. The Turbo will put him right in your listening room. I had my most remarkable session home alone on a Saturday morning. I blasted discs 2 and 4 from the strangely uncelebrated 6-disc set Live at the Blue Note: The Complete Recordings, a collection that captured Jarrett’s trio at its peak in 1994. Discs 2 and 4 each contain a version of "Things Ain’t What They Used To Be". On the disc 2 version, DeJohnette steals the show, playing Tony Williams to Jarrett’s Miles Davis. Finally at around 4:20 the modest Peacock shows his colours and what a display it is - understated but articulate rapid-fire virtuosity at the top of the neck, a perfect bridge between the brash Jarrett and the cocksure DeJohnette. The version on disc 4 is slower and played more deliberately, less playfully. I favour the disc 2 cut because Jarrett jaunts through the track with an upbeat Gospel-like cadence and there is more energy on display from all three musicians. Towards the end of the song, DeJohnette delivers a wondrous thunderous solo that makes John Bonham sound quaintly polite. My reaction was one of utter stupefaction. How could a 28-watt SET amp produce arrhythmic thunder like this? It was as close to concert-like as I have ever heard and felt in my listening room.

And I do mean feel. After listening to disc II in its entirety, I left the room and had the sensation one gets when leaving a great jazz concert in a small venue - the sense that one has been moved at some primordial level by this great music. No, my ears were not ringing but I felt as though the music—especially DeJohnette’s drums—had passed through me and enriched me in some formative way. The music stood as some sort of testament to the genius of the improvisational method and the Turbo had been necessary to realize that. No other amp had had that effect before. The Turbo tended to have this effect with all speakers I used. After a few weeks I began to notice that the Turbo had made my Tekton M-Lore speakers behave like they had with no other amplifier. There was some flesh, some warmth and body in the upper mid range that hadn’t been there before. There was a tonal density to all acoustic instruments, a richness and fullness that I didn’t know they could produce. Ordinary amplifiers will usually throw up flat banjo notes devoid of body and the cluck and clap of the open-back claw hammer style. The Turbo produces the most realistic banjo I have heard in my house other than the real thing. The Turbo built a sturdy bridge between the Tektons’ surfeit of energy at the frequency extremes and the small deficit or touch of hollowness in the midrange. These $600 speakers normally sound like $3’000 speakers but the Turbo seemed to make them sound even better.