Octave Audio V 80 SE integrated amplifier

As a salt-and-pepper–haired bachelor living in present-day Manhattan, I admit to participating in mating rituals that have included electronic divining tools and computer-aided pleasure machines. In a phrase: online dating.

From various sites whose names begin with O or M, and which can lead to S or M with a stranger who may or may not be who or what she claims to be, I've had private zones tickled silly, and as often have found the process to be confusing, depressing, or both. I've been happily hijacked by a flexible Broadway singer, met a she who was really a he, and even found employment, all through online dating.

As a wave of such memories rushed over me, I'd planned to audition the Octave Audio V 80 SE integrated amplifier ($10,500) using jazz LPs favored by erstwhile dating partners. Then Gregg Allman died, and everything changed. I played "Midnight Rider," from the Allman Brothers Band's rural-tinged second album, Idlewild South (LP, Atco SD 33-342). Then the 13:11-long version of "In Memory of Elizabeth Reed," from The 1971 Fillmore East Recordings (4 LPs, Mercury B0020496-01). And Duane Allman's torrid guitar solo in Boz Scaggs's cover of "Loan Me a Dime," from Duane Allman: An Anthology (2 LPs, Capricorn 2CP-0108). I was 15 again in 1972, smoking a joint at the Allmans' concert (they shared the bill with the Faces, Mahavishnu Orchestra, and Spirit) at Memorial Stadium in Charlotte, North Carolina.

Every solo that Gregg, Duane, and guitarist Dickey Betts recorded on the Allman Brothers Band's first three albums is burned to memory, collectively holy and magical. They dwell in a rare heaven with John Coltrane's tenor-saxophone solo in "Blue and Green," from Miles Davis's Kind of Blue (LP, Columbia/Legacy 88697680571); John, Paul, and George's sublime vocal harmonies in "Here, There and Everywhere," from the Beatles' Revolver (German LP, Hör Zu SHZE 186); and Frank Sinatra's 1958 ode to love lost, "Angel Eyes," from Frank Sinatra Sings for Only the Lonely (LP, Capitol W-1053). What's harder to explain is how the Allman Brothers' music captured the blue-sky joy of such Deep South highways as US Route 441 and Georgia State Route 11, molten asphalt trails that once offered a sense of danger, freedom, mystery, and magic.

Can a German-made, tubed integrated amplifier using the recent-production Tung-Sol KT150 power tube express the warmth of these classic Allman Brothers Band recordings, engineered for Atco by Tom Dowd? Or the urban grit of Rudy Van Gelder's engineering of the Blue Note LPs recorded by Hank Mobley, Wayne Shorter, or Joe Henderson? The transparent production of Roy DuNann's sessions for Contemporary Records? One thing is certain: Classic German technology—from Emile Berliner's Gramophone disc and player to Neumann and Telefunken microphones—has earned a hallowed place in every major recording studio of the last several decades. Could modern German audio technology impress within the confines of the not-so-average American living room?

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Description
Octave Audio's V 80 SE integrated amplifier is a push-pull, class-AB design that outputs 120Wpc into 4 ohms or 80Wpc into 8 ohms, and has a claimed frequency response of 10Hz–80kHz. The V 80 SE's four ovoid Tung-Sol KT150 beam-tetrode tubes speak of its power, and two diminutive 12AU7 dual-triode driver tubes and a lone 12AT7 twin-triode (split-mode) input tube are like wee knights guarding a castle keep. The V 80 SE's pre- and power-amp sections can be operated independently by selecting the Extern option, and the integrated allows—listen up, me brothers—the rolling of power tubes! Should you care to alter the Octave's prescribed flavor of KT150, just swap in EL34s, 6550s, KT88s, KT100s, or KT120s—the user-adjustable Bias-Measuring System will have you spinning vinyl and CDs in no time flat.

The V 80 SE's case is made from "a mix of steel and aluminum alloy," explained Octave Audio's executive director and chief designer, Andreas Hofman, via e-mail. "The aluminum parts are the ones that are visible. The inner steel chassis is utilized because of the stability and the magnetic shielding. The chassis's construction also serves to eliminate eddy currents to minimize magnetic-induced hum."

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Octave claims that the V 80 SE can manhandle any loudspeaker load down to 2 ohms: "The amp can handle a 2-ohm speaker load as the [KT150 tubes] are not operating beyond their limits," Hofman wrote. "The tubes still have reserves in case of a higher plate current and plate dissipation power. . . . Our transformer is optimized in respect of the phase shift to optimize the negative feedback. This matched system is stable down to 2 ohms as well as without load; this means the amplifier is not ringing under extreme load conditions."

This heavy-duty German integrated offers connections to an equalizer, signal processor, and a subwoofer; the option to use a separate preamplifier to control the V 80 SE's power amplifier; a Home Theater Bypass Circuit, to power a multichannel system; a biamping option; and an internal headphone amplifier. Extra-cost options include a choice of moving-magnet or moving-coil phono stage ($750), and Octave's Black Box ($1200) and Super Black Box ($3000) external power supplies. The V 80 SE features the most sophisticated circuit-protection, power-management, and soft-start functions I've seen on any amplifier. It measures 17.75" W by 5.9" H by 16.3" D, weighs 50.7 lbs, and is built like a Mercedes-Benz C112.

Octave manufactures their own output transformers—they began winding transformers in 1968, long before the 1986 launch of their first successful product, the HP 500 preamplifier, a version of which remains in the line—and hand-builds each amp in their factory in Karlsbad, Germany, using EPCOS electrolytic capacitors, Elma switches, and German-made Druseidt Elektrotechnik binding posts. Over the years, Octave has found success with the Jubilee (2003) and V 40 SE (2009) amplifiers—the latter reviewed by Art Dudley in August 2014—and the RE 290 power amplifier (January 2013).

Though the V 80 SE is chock full of functions, you wouldn't know it to look at its streamlined, ¼"-thick faceplate. The main power switch is on the left side panel, just behind the front panel's protruding edge. On the left side of the front panel are a large rotary knob to select among inputs: Phono, CD1, CD2, Aux, Tuner. A smaller input knob addresses Source, Tape, or Front Channel (in power-amp–only mode). At the center of the faceplate, a rectangular window frames a column of LEDs, one per input, followed by columns for the power tubes' bias adjustments and the amp's operating status: Protection, Soft Start, Extern, Headphone, Front Channel, Ecomode. A second small mode knob switches among Linear (play mode), Extern, and Bias. Last comes another large knob, for adjusting the volume. The provided remote-control handset adjusts only the volume level.

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The V 80 SE's rear panel is an orderly maze of RCA and XLR jacks, switches, and other connectors. On the left side are eight pairs of RCA jacks, labeled CD2, Tuner, Master In (power amplifier input), Master Out (preamplifier output), Tape Rec, Tape Play, Pre Out (subwoofer), and Front Channel. Above these are the Headphone and Ecomode toggle switches, the Aux and Phono RCAs, a ground screw, and a pair of balanced (XLR) CD inputs. At center are two pairs of Druseidt speaker binding posts, a two-position Power Selector switch, which should be set to High 110W for use with KT120 or KT150 tubes, or to Low 70W for use with KT88, 6550, KT90, KT100, or EL34 tubes, and the solitary, 6.3mm headphone socket. (That's right: you plug your 'phones into the rear.) On the right, completing the maze, are the IEC socket, the fuse bays, and the connector for the Black Box power-supply upgrades.

Setting up
Along with the power and triode tubes, Octave supplies an extra power tube, a power cord, two small screwdrivers, an owner's manual, and a pair of white gloves for gently inserting each tube in its socket, once the vented tube cage is removed. After powering up the V 80 SE and waiting about 60 seconds for the soft-start LED to disappear, I set the bias for each power tube, knowing that I'd have to rebias them following run-in. But after that, the bias settings remained constant throughout my listening.

Octave's biasing system is ingenious. When I clicked the small mode knob to Bias, four columns of three LEDs each appeared on the display, one column per power tube. Starting at the top, the three LEDs in each column glow red, green, and yellow. For the KT150s, the red and green LEDs should be simultaneously lit, adjustment achieved by inserting the supplied 3mm screwdriver in the tiny hole beneath that tube's LED column and turning clockwise (to increase current) until the desired colors appear and remain stable. Easy!

Warming up
Out of the box and for its first 20 days of use, the Octave Audio V 80 SE was the most unlistenable amplifier I've ever tried: bright, forward, and generally eardrum-splitting. It took the V 80 SE a solid month of nearly constant use to find its happy-friendly footing. I never became completely enamored of the sound of the Tung-Sol KT150 power tubes, but learned to respect what they did very well indeed: grain-free highs, very powerful and dynamic bass extension, and neutral, clear-headed sound.

COMPANY INFO
Octave Audio
US distributor: Dynaudio North America
1852 Elmdale Avenue
Glenview, IL 60026
(847) 730-3280
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COMMENTS
BradleyP's picture

The ability to drive 2-ohm loads certainly indicates power and current, but what speakers in production today present a nominal 2-ohm load? Some full range ribbons of the 80s and 90s presented that and worse, but isn't that behind us, now?

John Atkinson's picture
BradleyP wrote:
The ability to drive 2-ohm loads certainly indicates power and current, but what speakers in production today present a nominal 2-ohm load?

If you look at the impedance measurements I publish with Stereophile's speaker reviews, you will see that quite a few speakers drop below 3 ohms, particularly in the lower midrange, where music has a lot of energy. And when you consider that the electrical phase angle can be often be quite high when the impedance is low, exacerbating the drive difficulty, I think that judging an amplifier on its ability to drive 2 ohms is eminently reasonable.

John Atkinson
Editor, Stereophile

BradleyP's picture

I'm honored to be schooled by the best. Thank you, sir.

mrkaic's picture

... the third harmonic is down 54 dB, not 64 dB.

John Atkinson's picture
mrkaic wrote:
the third harmonic is down 54 dB, not 64 dB.

Good spotting. I corrected it.

John Atkinson
Editor, Stereophile

mrkaic's picture

Is it just me or are the KT150s some of the ugliest tubes out there? Much prefer the classic look of KT88s.

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