In addition to the parts seen under the hood, if you peer through the vents on top, you’ll find two large toroids mounted sideways, two massive output transformers and two small input transformers to handle the 6EM7 tubes. When you include the $450 retail in tubes provided, there must be at least $3000 retail in parts plus an expensive chassis. And let’s not forget the cost of labour in a high-wage nation. In my last review for 6moons, I heaped praise upon the Coincident Dynamo SE, a single-ended pentode design based around the 6SL7 and EL34 tubes. That small but heavy amp now lives in my house where it has utterly transformed my second system, imparting speed, exceptional bass control, an alluring sense of warmth and a fatness of tone I never thought possible to achieve for $1’299. The Turbo 845 SE delivers everything its smaller brother does but multiplied by four. Almost four times the power (28 watts). Four times as many inputs. A tad more than four times the price. And almost exactly four times the weight. For your $6K you get the same sort of stunning stainless steel chassis as the Dynamo but beware since it’s also a fingerprint magnet. You get high-quality binding posts and wiring throughout the amp, a ground lift switch, three gold-plated RCA inputs and a pre-in function. As with all other Coincident products, you are paying for the highest-quality Japanese 6N copper and silicon steel.

The power and output transformers are at the heart of this 40kg amp. The power supply stores over 510 joules. The Turbo sports four proprietary coke-can capacitors and many more small ones, all of good quality like Rubycon. The general theme is polypropylene. Capacitance is twice that of some US-made amplifiers costing four times as much. This might explain the Turbo’s cheetah-like speed and its solid-state bass control. Unlike many inexpensive Chinese-made 845-based amplifiers, the Turbo parts are more than robust and certainly equal to the task of dealing with the 1200 volts coursing through its veins. The Turbo is a near-dual mono design. Only the chassis and power supply are shared. It is auto-biased and hard-wired. The volume is muted upon start-up regardless of the level you'd last set at turn-off. The volume knob is located on the top front of the amp, making it impossible to see just where the knob is set from your listening seat. On the positive side, the four inputs each have their own coloured LED in white, yellow, green and red. The remote control is heavy but just the right size, designed for a human hand not a Sasquatch. It’s refreshingly understated. The remote handles source switching, muting and volume. The volume is adjusted using a discrete resistor setup. It works flawlessly, advancing neither too fast nor too slow. The headphone port’s output impedance is 300Ω but you can request another value. With low-Z headphones, I had hum during soft passages. With 600Ω headphones like my Beyerdynamic DT880, there was very little noise and enough juice to thrash drivers within millimeters of their lives.

The Turbo is equipped with ‘entry-level’ Psvane 845 that must be considered an upgrade over the ubiquitous Shuguang. I use the Psvanes on my Line Magnetic 518IA but during my time with the Turbo also had the use of Psvane’s incredible T-II 845 (currently $399 from Grant Fidelity) and WE 845 Replica ($649 from Grant Fidelity), both on review for The T-II adds a touch of liquidity and warmth. The WE adds grip, dryness to the bass and lowers hum and noise substantially. I used upgraded 300B black bottles in the driver stage. The Turbo ships with standard clear bottles. Rectification is by high-speed Hexfred diodes. And now we come to the most interesting aspect of this amplifier; its use of NOS 6EM7 tubes in the input. This tube is a readily available inexpensive double triode once manufactured by RCA for amplifiers and televisions.

Recently it has gained a niche following in the DIY community as a headphone amp driver and even as an output tube in low-powered SET designs. Blume said in an email that after many years of "experimentation with every conceivable input tube, the 6EM7 proved…the best suited" to his goals. "It has four times the current capacity of the ubiquitous 6SN7. It has so much current that it requires its own power supply and power transformer. It’s very costly to implement but worth it. It accounts for the deep impactful bass, wide dynamics and overall transparency and purity." I couldn’t agree more. Hooked up to the SVS Prime tower speakers which were in for an upcoming review, the Turbo delivered among the deepest bass I have experienced in my room until now.

As I wrap up my description of the Turbo’s guts and its impressive physique, one word of warning. This is a heavy and enormous amplifier. It’s lopsided, with little in the middle but much in the back. It will likely protrude from your rack. Just to be safe, I ripped a piece of Plywood to place atop my flimsy rack, using Blu-Tak to secure it. And I had to turn my rack on its side to accommodate the Turbo’s unusual depth. Obviously it’s a bit awkward but it’s better than a two-box solution and in fact reminds me of the Audio Note footprint. As for the sound, the Coincident Turbo puts you in Audio Note Jinro territory for less than ¼ the price. I began my intensive listening with jazz guitar-based music: Russell Malone, Joe Pass, Herb Ellis. The Turbo was a perfect match, even better than any 6V6 or 6L6-based amp I owned or demo’d. That includes brands like Leben and Air Tight.

The Turbo imparts a sense of muscularity and elasticity, somewhat like the tone of a vintage Sylvania 6L6WGB so prized by most Blues guitarists, many Jazz guitarists and some rockers too. But a 6L6 will yield just 6 or 7 watts configured in single-ended mode. I see this amplifier as a sort of 6L6 tone freak’s dream come true for its ability to coax that punchy and fluid sound out of medium-sensitivity speakers and deliver floor-shaking bass. There’s a bit of that compressed tone that Blues breakers crave but the Turbo could not be accused of compressing the soundstage. On The Bridge, the punch of Jim Hall’s guitar belied his small footprint on the stage where he tended to sit and avoid drawing attention to himself. The Turbo created a massive soundstage, turning the Tekton M-Lore, Harbeth Compact 7 and SVS Prime into panel-like holographic giants.

Emily Remler died too young and not famous enough. She burst onto the scene at the age of 24 with her 1981 album Firefly. It was widely acclaimed and seemed to herald a promising career but just seven albums and nine years later, Remler lay dead in Australia, another tragic victim of the needle. Sadly she seems to have faded from the memory of most Jazz lovers.

With the Turbo hooked up to my Harbeths, Remler’s guitar was rich and meaty. You would swear one minute that she grew up in the house Wes built, the next minute that she seemed to walk on a far-out limb, presaging the Abercrombie and Rosenwinkel style of the 1990s-2000s. Just like the Coincident Dynamo, the Turbo excelled at capturing all that is wonderful about a tonally saturated Jazz guitar. I’m no synesthete but as I listened to Remler’s hypnotically über-overtoned rendition of "In a Sentimental Mood", I struggled to describe its ineffable beauty.

The sound was so warm, rich and inviting, smothering even. Perhaps the warm red block pattern in my carpet explained why Remler’s playing conjured up images of Matisse’s "Harmony in Red." Whatever the heck I was hearing, it was unusually fascinating. And the reason for it was undoubtedly the Turbo.