Reviewers' ChoiceCall it Pavlovian, but nowadays I’m so used to seeing and hearing reasonably priced tube amps made (if not always engineered) in China that I’m sometimes surprised when I encounter something made elsewhere. And even though the wave of Chinese imports seems to have grown into a tsunami, it doesn’t mean that everyone else has packed up and gone home. I’m talking about some old- and new-school audio names based in North America, some exotic Italian and French gear, and some of the more traditional-looking and great-sounding English brands. All of these firms from these many places, and more, are still around, growing and, I hope, thriving. So with this in mind, I got my hands on a spanking bit of kit that hails from the land of great engineering, great soccer, and even greater Pilsner. 

Octave V 40 SEOctave Audio may be as new to you as it was to me, though they’ve been around for a while. Based now in Carlsbad, Germany, it was founded by Karl Heinz Hofmann as a transformer manufacturer in 1968. Hofmann’s son, Andreas, began building amplifiers as early as 1975, and took over from his father in 2000, at which time he changed the company’s name to Octave Audio. Andreas, Octave’s head of design, product development, and chief executive officer, believes that tubes are inherently more musical devices than are transistors, a belief summed up nicely on Octave’s website: “His recipe: Tubes for sound-relevant circuit parts, modern semiconductors for tube circuit periphery.” Some tube neocons may disagree, preferring the purity of old-school circuits and components made from Malaysian fruit-bat poop or what-have-you, but I like the idea of tube power married to a modern, reliable, stable platform. If this can wring even more performance from good old tubes, I’m all for it, as long as the solid-state core doesn’t end up overwhelming or changing the overall gestalt too far in the other direction. 

Octave makes three integrated amplifiers: the more powerful V 70 SE and V 80, and the subject of this review, the 40Wpc, entry-level V 40 SE ($4900 USD). Besides these integrateds, Octave cranks out very high-end pre- and power amplifiers, and a highly rated modular phono stage. 


The Octave Audio V 40 SE is beautifully constructed, with a thick, silvery, brushed-aluminum faceplate (also available in black) and a metal case and chassis. Fit and finish are first-class. I had exactly zero problems operationally, and none in fitting the moderately sized V 40 SE into my standard-size rack. At 40 pounds it’s no featherweight, but it’s not really all that heavy for a tube amp (the weight is concentrated in the rear, where the transformers are; when lifting, a good grip is essential). The V 40 SE produces a claimed 40Wpc into 4 ohms, operates in pentode mode, and optimally drives speakers with nominal loads ranging from 3 to 10 ohms and sensitivity ratings of 85dB or more. Compared to its predecessor, the V 40, the SE has larger coupling capacitors on the power tubes and ultra-low-leakage tantalum electrolytic caps, and work has been done to decrease the noise and hum produced by the tube-heater system. 

The front panel is a model of utility and ease of use. Two oversize knobs flank a central display: the right knob handles volume, while the left is used to select among five single-ended RCAs, one Home Theater Bypass, and a setting for biasing the power tubes. Using the last couldn’t be easier: The display includes a series of amber, green, and red LEDs, each corresponding to one of the output tubes. Simply insert the blade of a small screwdriver (supplied) into the small hole at the base of each LED string and dial in the appropriate bias setting by lighting up the LEDs in various combinations. For instance, a green and a red LED lit together sets the amp for High Bias (suitable for KT88s and 6550s, etc.); yellow and green LEDs indicate Low Bias (for EL34s, KT66s, and so forth). If you always thought tube amps required futzing with meters and probes and all the care and attention of a household pet, then the V 40 SE will prove you wrong. 

Around back are the requisite IEC socket, and sturdy binding posts with large plastic knobs that are easily tightened by hand, and mercifully devoid of any of the irksome Euro-spec safety crap that I found on the Pathos Logos, which I recently reviewed. Two outputs are also available: one for recording, and the other a subwoofer output with buffering intended to prevent the sub from affecting the amplifier’s performance (a subwoofer with its own level control is required). There’s also a grounding plug for a turntable, and just above that a small switch that allows the amp to be switched to run in Ecomode. 

Ecomode is part of the Power Management System, which is what Octave calls the V 40 SE’s logic-controlled power grid. In addition to monitoring output-tube heaters and high-voltage rails, to protect the tubes and internal parts (caps, rectifiers, etc.) from high turn-on current, monitor tube health, and protect the entire V 40 SE from tube failure, the PMS allows the amplifier to be switched into a far less power-hungry standby mode. If the V 40 SE receives no signal for nine minutes, Ecomode is activated (assuming it’s been turned on), and switches off the heater voltage and the high-voltage power for the power-amp section. When a signal is sensed, the amp then wakes up and, after a warmup/startup delay of 35 seconds, resumes normal operation. This sleep mode reduces power consumption to under 20W, down from a current-slurping 140W. With environmental standards tightening not only in Europe but here in North America as well, I think this is an excellent feature that will reduce operating costs while prolonging tube life -- a win/win if ever there was one. 

In keeping with the overall classy build quality of the V 40 SE itself, Octave supplies a remote control that can be programmed to operate multiple devices via a touchscreen display. And finally, one of two outboard power supplies, the Black Box and the Super Black Box, are available as upgrades at additional cost. These simply plug into the power socket on the rear panel and increase the power-supply capacitance by a factor of four or ten, respectively. The V 40 SE’s manual points out that adding one of these supplies lets the amp drive more difficult speaker loads, while at the same time improving various performance parameters and the filtering of the mains power. I auditioned the V 40 SE without either Black Box. 

Does it go? 

Octave supplied me with two types of output tube, KT88 and 6550, and I burned each set in for 100 hours before settling down to listen critically. I began with the 6550s because I run them in my Cary SLI-80 integrated, and because I felt their brawn would best help a 40Wpc tube amp to drive my Red Rose Rosebud 2 speakers. 

Drive was certainly not an issue -- I was astonished at how powerful the V 40 SE seemed to be, and how easily it elicited dynamic jump from the Rosebuds. But though the sound was incredibly transparent and detailed -- with some recordings, I could hear a fly belching on the back wall of the recording studio -- it was also too tonally threadbare for my liking, sounding a little dry and matter-of-fact. This sort of sound was useful for squeezing every last drop of detail from a record, but it wasn’t something I could settle in with. Substituting the KT88s, I lost almost none of the transparency and detail, while gaining what seemed like tons of texture, image density, and harmonic complexity across the board. 

With the KT88s fully broken in, the V 40 SE served up a sound of beguiling clarity and transparency that never sounded etched or sharp. Just as some single-ended-triode (SET) amps can do, the Octave managed to somehow clarify the soundstage and make everything sound more immediate. It wasn’t just a question of hearing things I’d never heard before; instead, there seemed to be a new freshness to the sounds of records I’d heard many times before -- as if they’d been mastered yesterday instead, as in some cases, many decades ago. This was especially apparent with live recordings, such as Bill Evans’ Waltz for Debby (24-bit/96kHz AIFF, HDtracks); or something like the Chesky’s 4 Generations of Miles (24/96 AIFF, Chesky/HDtracks), where the crowd chatter and noise seemed reach-out-and-touch-it real. In fact, the V 40 SE was a great companion for all the high-resolution downloads in my music collection, many of which duplicate stock “Red Book” CDs. Across the board, the V 40 SE obviated the greater spatial depth and detail of the higher-rez recordings, and let me clearly hear how some of the “Red Book” CDs seemed to bunch up in the treble range, and get hard when the music’s intensity increased. 

To compare, I played all my digital files, ripped in AIFF and stored on my Apple MacBook Pro, through the Amarra 2.2 music player. Listening to the CD rip of the Chesky recording, it was pretty easy to hear how George Coleman’s tenor sax sounded strident, and Mike Stern’s guitar tone was much more edgy, compared to the more fluid, relaxed, and texturally rich sound of the 24/96 download. Ditto for the reproduction of space, which was altogether 2D and flat from CD, vs. the breathy and altogether more dazzling hi-rez recording, which laid out the players with lots of elbow room and image density. 

Things got even better when I began playing vinyl. If you’re a fan of Dead Can Dance’s Into the Labyrinth, or their swan song, Spiritchaser, then do yourself a favor and pick up Mobile Fidelity Sound Lab’s new Silver Series reissues of both albums -- what sounded merely superlative on CD is mind-blowing on these 120gm beauties pressed at RTI. The V 40 SE served up palpable images and rich, meaty instrumental textures with aplomb. From Into the Labyrinth (LP, Mobile Fidelity MOFI 2-001), recorded in an Irish church, I could hear voices and instrument decay trails reverberating throughout the ample acoustic, yet every singer and instrumentalist was firmly rooted and positioned with unerring precision. 

What I didn’t get from the Octave was any of the burnished glow, or quite as much of the tube bloom, that some other tubed integrateds can deliver. Instead, the V 40 SE seemed to be a very linear device capable of considerable extension at both ends of the audioband. Fed a diet of poorly recorded music, regardless of format, it gave back a clear idea of just how bad those recordings were; conversely, good and great recordings sounded spellbinding. That immediacy and that crystalline sound came at the expense of a certain amount of editorializing: the aforementioned bloom and golden richness, and the fat midrange, that many have come to associate with tube power. Are these bad things? Compared to my Cary SLI-80, which revels in its traditional tube sound, the V 40 SE was a much more straightforward product that presented a more detailed, transparent, and honest sound that still had that liquidity and flow that make tube amps so lifelike and fun to listen to. 

Where my Cary SLI-80 in triode mode can create a vast acoustic, the Octave integrated at first sounded smaller. This, however, proved illusory; careful listening and comparison revealed that the triode amp sounds airier but is in fact less accurate, not passing along many of the ambient details that make each recording venue more distinct from the others. The Octave V 40 SE made all of this much more distinct and obvious. It also had more than ample soundstage depth and width, if the recording contained that information, and was simply much more honest and true to the original recordings. I love the sound of the SLI-80, but the V 40 SE was the more accurate and descriptive device. 


The Octave Audio V 40 SE is more than a bit special. It combines the grip and drive of a much more powerful amplifier with levels of transparency and detail that you’d be happy to find in a far more expensive product. It appeals to both the heart and head, and delivers a sound that modernizes traditional notions of what a tube amplifier at this price point can be and do. Yes, that might mean that those of us who are familiar with traditional tube sound will have to adjust our ears slightly, but the V 40 SE provides such a comprehensive, immediate, liquid, and transparent sound for virtually any genre of music that the adjustment is painless. For those in pursuit of excellent sound regardless of output device, who want set-and-forget convenience and reliability, and are looking in this price range or even much higher, I can’t recommend the Octave Audio V 40 SE highly enough. 

. . . Graham Abbott 

Associated Equipment 

  • Analog source -- Nottingham Spacedeck turntable with Heavy Kit, Wave Mechanic and Space tonearm, Ortofon Jubilee MC cartridge, Holfi Battria SE phono stage
  • Digital sources -- Cary 303/200 CD player-processor; Apple MacBook Pro with internal SSD, 8GB RAM, external 1TB FireWire hard drive; Amarra 2.2 player; Wavelength Wavelink USB-to-S/PDIF 24-bit/192kHz converter
  • Integrated amplifier -- Cary SLI-80
  • Speakers -- Red Rose Rosebud 2
  • Power cables and conditioners -- Shunyata Research Guardian power conditioner, Harmonic Technology Fantasy AC cords, Yamamura Churchill Series 5000 AC cord (phono stage only)
  • Speaker cables and interconnects -- Harmonic Technology Magic, Kimber Kable Hero interconnects; PS Audio Extreme Reference speaker cables
  • Accessories -- 70-pound custom speaker stands, Stillpoints and Risers isolation devices, Final Labs ball-bearing isolators, Quantum Resonant Technology power conditioner, Lovan Equipment rack (foam filled)

Octave Audio V 40 SE Integrated Amplifier
Price: $4900 USD.
Warranty: Three years parts and labor.

Octave Audio
Industriestrasse 13
76307 Karlsbad
Phone: +49 0 72 48 / 32 78
Fax: +49 0 72 48 / 32 79 


North American distributor:
Dynaudio North America
1140 Tower Lane
Bensenville, IL 60106
Phone: (630) 238-4200
Fax: (630) 238-0112