Way back in the age when Stereophile’s print magazine was the size of a theater playbill, common wisdom declared that the tube preamp was the ideal complement to solid state amplification. That axiom was rooted in two assumptions: (1) Tube equipment produces softer, warmer, more flowing and pleasing sound than solid state, and (2) transistor-based devices need some softening because their sound is often hard, brittle, and mechanical. The trope was the high-end audio equivalent of the yin/yang stereotype that depicts women as soft, gentle, pliable, and flowing and men hard, harsh, and unyielding. Godzilla the Hun weds the Celestial Mermaid.

Over the past few decades, advances facilitated by research, computer modeling, and higher-quality parts have helped transcend the tube-vs–solid state dichotomy. Most of the solid state amps that I’ve reviewed in the past decade have delivered sound I consider organic and musical (footnote 1). While each had its strengths and shortcomings, the majority sang in a unique voice and achieved brute force and delicacy with equal aplomb. While my opportunities to review tube amps and preamps have been fewer, almost all the differently voiced tube components I’ve reviewed have also produced organic, full-range sound distinguished by dynamic attacks and delicate details.

Apparently not everyone has shared my experience. Take, for example, Andreas Hofmann, the owner and chief engineer of Octave Audio of Germany. When I Zoomed with Hofmann and John Quick, VP of sales and marketing at Dynaudio USA, Octave’s US distributor, to discuss the Jubilee Hybrid, Octave’s flagship linestage preamplifier, Hofmann asserted his belief that tubes deliver superior sound.

“You can design the same hybrid circuit [that’s in the Jubilee preamplifier] without tubes, using only solid state transistors or even op-amps,” he said. “But for me, even though I cannot say why a tube sounds better and more musical than solid state, tubes have a more human touch.”

Which leaves the ball, as it were, in my court. How does music reproduced through the Jubilee preamp sound, and how does it make me feel?

Exploring the Jubilee
The latest iteration of the Jubilee preamp, which was introduced in 1998, remains a zero-feedback, two-stage hybrid design with a tube-based “precision balancing stage” with four ECC82 tubes and a semiconductor-based, discrete output stage. The tubes, which are sourced from either JJ in the Slovak Republic or Russian companies, are carefully matched to ensure optimal sound.

Octave’s website (footnote 2) and manual (footnote 3) offer a lot of insight into the technology behind the sound. The company says that the Jubilee preamp’s tubed precision balancing stage generates signals that are “absolutely constant phase and amplitude symmetrical”; this ensures that “no phase or time error will occur between phase and antiphase of the balanced output signal.” The preamp’s feedback-free output stage employs semiconductors as the basis of a “unity gain power buffer” that’s responsible for the preamp’s “extremely low-impedance output” and high current delivery. This is another way of saying that the transistors in the Jubilee’s output stage do the hard work, leaving its tubes free to generate the preamp’s unique sonic signature.

As much as Octave believes that zero feedback delivers optimal sonic purity, its website acknowledges that successfully implementing zero feedback designs is not easy. Success requires “an almost perfect power supply with extreme stability, low noise, and low hum.”

The manual elaborates on the challenges posed by zero-feedback designs. “Any amplifier that dispenses with negative feedback also dispenses with the corrective mechanism provided by negative-feedback circuitry. In the Jubilee preamplifier, we solve this problem through the extremely high specification of the output stages and power supply section, creating virtually perfect conditions for achieving perfectly accurate amplification without the need for corrective mechanisms.” (footnote 4) After perfecting the Jubilee preamp’s design over decades, the company claims that it will now deliver optimal sound quality “with virtually any amplifier.”

Hofmann, who began designing components at age 16, discussed this further during our interview. “If you want to design a tube preamplifier with zero feedback, you have to optimize every aspect of the power supply that you need for the tubes: plate voltage, heater voltage, for everything,” he said. “If you have feedback, you can use a poor power supply because the amplifier is regulating these factors. If there is zero feedback, the power supply must be better.”

Quick offered additional commentary. “Feedback makes amplifiers and preamplifiers more stable, with lower distortion into a much broader range of loads. The Jubilee was the first preamp that Andreas engineered that was a combination of tubes and transistors, used zero feedback, and was bulletproof, stable, and measured well.”

The Jubilee’s XLR inputs, which I used exclusively, are equipped with unity-gain isolation transformers. According to Hofmann, these “have no sonic signature of their own. They also function as a ground lift circuit and are particularly helpful for ground problems in complex multi-amp combinations,” because hum can happen even in circuits with fully balanced connections.

The preamp’s soft-start function, which gently increases heater and supply voltage over a period of four minutes, is a central part of a power management system that’s designed to protect the unit and maintain tube life to its theoretical maximum of 10,000 hours. To quote Hofmann, “Without the regulation introduced by feedback, the amplifier takes a longer time to stabilize itself. I don’t want to push high currents into the unit to make it turn on faster, because it would be bad for the parts. It makes no sense.”

Octave offers a choice of attenuators: the standard one (which I used), which can be adjusted with Octave’s extremely simple remote, or for $3500 more, a precision-resistor stepped attenuator with 47 steps; if this option is included, the volume must be adjusted by hand. In an email, Hofmann cited some benefits of the stepped attenuator: “Better channel matching, within 0.1dB, and more microdetails—it sounds banal, but it is true. Finally, a higher differentiation in the mids and highs—especially in depth.”

The Jubilee preamp also includes a home-theater bypass and monitor/record output for use with tape recorders.

When asked to describe the sonic differences among Octave’s three linestage preamplifiers, Hofmann said, “Refinement. The basic design of the Jubilee is exactly the same as it was 25 years ago, but it is yet more refined. There are internal changes—very fine details, including the quality of the parts and the layout—that you cannot see easily.

“Zero feedback is so extremely sensitive. That’s why I now use special resistors and caps that were not available 25 years ago. It took a long time to find perfect resistors that have good sound, good technical specs, and guarantee long-time stability.”

“The most important thing for me is that this is a hybrid preamplifier that uses four tubes. For me, it’s more or less impossible to make a pure tube preamplifier that has an output stage as strong as the Jubilee’s. It’s impossible. This design and this sound are only possible in a hybrid design.”

Chassis and functions
The Jubilee preamp’s 38lb solid aluminum body is equipped with handles that make placement a snap. The 25lb outboard power supply has a handle, too, but it doesn’t need it as much because it is smaller, lighter, and easy to position.

The electronics inside the Jubilee pre have been updated, but its design and layout are decidedly old school. The preamp’s front panel features three large knobs. The center knob adjusts volume. With the only volume demarcation line on the knob’s side, where it cannot be seen from the listening position, and no volume readout, the only way to match levels for accurate comparisons is by attaching a voltmeter to a speaker’s input and playing test tones, such as the 1kHz warble on Stereophile’s Editor’s Choice CD (footnote 5). (This is the most reliably accurate way to match levels in any system.)

Source selection on the Jubilee is unusual. The left knob has four positions: Muting, Source, Tape 1, and Tape 2. Just above these sources is an LED and a label (“Operate”) that looks like the labels on this knob but doesn’t correspond to a knob setting. When you initiate the soft-start cycle by depressing the power button on the power supply, the LEDs next to Source and Muting are activated, and the sound is muted. Once the soft-start cycle is complete, the preamp automatically unmutes, the Muting LED turns off, and the Source and Operate LEDs light up: the source is selected and it’s time to play music.

On this same, leftmost knob, selecting Tape 1 or Tape 2 activates those inputs. When Source is selected, whichever input is chosen on the right-hand knob becomes active. This right-hand knob selects among five inputs: Phono, Tuner, Aux, CD, and CD Sym for balanced (XLR) inputs.

At the center of the top panel of the main preamp chassis are four buttons labeled Gain, Phase, Copy, and, most cryptically, 2-1/1-2. These last two buttons allow you to copy a tape from Tape 1 to Tape 2, or vice versa. When the second-from-right button is set to “off,” whichever source is selected with the Source knob is routed to both Tape outputs. Old-school.

I never used the tape functions, but I spent considerable time with Gain and Phase. High Gain, the preferred position for most power amplifiers and loudspeakers, is indicated by a green LED situated behind and to the left of the Gain button. Low Gain is recommended for use with high-sensitivity speakers or very high-gain amplifiers. When Low Gain is chosen, a green LED behind and to the right of the button lights up. I used High Gain throughout the review.

The Phase button, when activated, inverts absolute phase. According to Hofmann, “When inverting phase, there are no additional components (or op amps) at play. The tube amplifier gain stage of the Jubilee pre feeds a solid state output buffer circuit that is connected directly to the XLR output jacks. When the phase-inversion button is pressed, the circuit reverses the plus (XLR Pin 2) and minus (XLR Pin 3) of the XLR outputs.” The RCA output is connected in parallel with the XLR output, so its phase is inverted as well. The rear panel’s input section includes two pairs of XLR inputs—CD SYM and Phono—four pairs of RCA inputs, and three toggle switches. The first of the RCA inputs is labeled CINCH; apparently that’s a European name for an RCA input. The others are labeled TU for tuner, AUX, and CD. Two of the switches enable you to select either the XLR or RCA inputs for CD and Phono inputs (the input labeled CINCH is the RCA alternative to the XLR Phono connection); the third switch controls grounding on the XLR inputs, allowing you to choose between “Connect to Ground” and “Disconnect” (eg, ground lift).

There’s a small, separate section for Tape, with, for each of the two Tape circuits, inputs on the right (PLAY) and outputs on the left (REC). On request, a “home-theater” bypass can substitute for the Tape 2 input. In the separate output section are two pairs of RCA outputs and two more XLR outputs. Finally, there’s a grounding terminal and an umbilical receptacle for the outboard power supply.

Review strategy, setup, and operation
We like to think big in Serinusland. My initial plan was to evaluate the Octave Jubilee preamp on its own merits and then compare it with my two solid state reference preamps, the much more expensive, three-piece D’Agostino Relentless ($150,000) and one-piece Soulution 727 ($77,975 without phono). This plan, though, encountered an obstacle: shelf space. With assistance from friends and the husband (who can sometimes also be friendly), it wasn’t too difficult to remove the Relentless from the top shelf, replace it with the Jubilee, install the Jubilee’s power supply on the shelf beneath, and support everything with Wilson Audio Pedestals. I began my review with this setup.

Preamp comparisons, however, required moving several large components in and out of my nine-shelf Grand Prix Monza double rack. After lowering a shelf two notches—I couldn’t have done it without you, Scott—I was able to fit either the D’Agostino or the Soulution on the top shelf and the main chassis of the Jubilee preamp on the shelf below. Alas, there was no room in (or on) the inn for the Jubilee’s power supply. So I placed said power supply atop the mammoth Stromtank S-4000 MK-II XT power generator. Concerned about the possibility of electromagnetic radiation pollution from the Stromtank, I placed two heavy HRS DPX-14545 Damping Plates between it and the power supply. Pedestals provided further isolation.

During the reviewing period, I started to worry that the sound, as good as it was, was compromised by EMI. That’s when I remembered the Grand Prix Formula Shelf (footnote 6) that sat unused under my couch. With assistance from Off Islanders Audio Society members Stan Delles and Paul Rickert, I installed the platform between the Stromtank and the Jubilee power supply, with the HRS Damping Plates and Wilson Audio Pedestal on top. We all sat amazed at the degree to which extra isolation enhanced the Jubilee’s presentation. I stuck with this setup for the remainder of the review.

Some minor damage occurred during shipping. The top center plate, which hosts the Gain and Phase push buttons, shifted ever so slightly forward, preventing buttons from popping out. I freed the buttons by reaching over the preamp and pushing the top plate forward a hair.

Even so, the Jubilee presented a few logistical challenges. If you’re short like me and place the Jubilee high on your rack, it’s difficult to see which Gain or Phase LED is lit. Even if you put the Jubilee on a lower shelf, the shelf above may block your view of those LEDs. Octave could save some Jubilee owners some tsuris by replacing the push buttons with toggle switches. This would also make those LEDs dispensable.

Another challenge: The Jubilee preamp’s remote volume control and the music room’s heat pump remote operate on the same frequency. Every time I adjusted the temperature in the room or switched between heating and cooling, the volume went askew. On one occasion, only a fast move on Scott’s part saved my speakers from possible damage. After that, I lowered volume all the way before starting a new track or album.

It quickly became clear that the “Connect to Ground” setting delivered a fuller, richer, tighter, more profound bottom end, with weightier images and increased transparency, than I heard with the ground floated. After adjusting that setting, I was ready to begin taking notes. Throughout the review period, the Jubilee operated without buzz or hum. And it was a total joy to listen to.

Jubilee = sonic bliss
During my first serious listening session, no matter what music I cued up, the word that played on repeat in my head was “beautiful.” It’s a lovely word, but what does it mean?

I began with a track from a superb recording I’d just reviewed for the August issue, Arvo Pärt’s Spiegel im Spiegel, performed by violist Rachel Yonan and pianist Kwan Yi on the album Kiss on Wood (24/352.8 FLAC, Sono Luminus/download). The sound was quite clear if not totally transparent, and the images full, round, and bursting with life and abundant detail.

But there was something more—a seductive smoothness in the midrange that left me in a state of wonder. There was no excess sweetness to detract from the viola’s unique tang. Like when you take the first bite of a perfectly steamed organic zucchini in which traces of natural sweetness and tarter flavors harmoniously intermingle with its predominant green core (footnote 7). Wine connoisseurs could come up with other analogies—eg, “a savory mix of chocolate, anise, and licorice with a whiff of tart berries and a smooth-as-velvet finish reminiscent of the frescoes in the private palace in Venice that I visited with the editor of Vogue that glorious summer in Italy”—but we’d be describing the same experience: sound so inviting, satisfying, and easy to listen to that it transports you to a place beyond words.

Eager to explore more, I put on L’extase: Debussy & Messiaen (24/192 FLAC, Pentatone/download), a marvelous recording by mezzo-soprano Magdalena Kožená and pianist Mitsuko Uchida, which I reviewed in the September issue. I sat in awe. Every note of Uchida’s revelatory artistry and every vocal inflection seemed laid bare. The sound was gorgeous and flattered Kožená’s midrange no end.

Deeper into romantic excess I dove, with an old favorite: the studio recording of the Immolation Scene from Wagner’s Götterdämmerung (24/192 FLAC, Columbia/Qobuz), performed by soprano Eileen Farrell and the New York Philharmonic under Leonard Bernstein. Farrell is underrated, perhaps because her instrument was so sensational that she often coasted on its laurels rather than sinking as deeply as possible into the music and her character. But Bernstein had a special rapport with Farrell, whom he clearly adored, and knew how to masterfully coax out everything the great soprano could create. Every instrument, every note was highlighted and gorgeous. Percussion was strong, the soundstage huge and deep. The maternal warmth of Farrell’s midrange and lows was one of her many gifts, and the Octave Jubilee highlighted it beautifully, if not with ultimate transparency. As good old Brunnhilde urged her faithful flying horse, Grane, into the flames, and they and the kingdom of the gods fried to a crisp, I was ecstatic.

Knowing that Andreas Hofmann holds the core European classical composers close to his heart, I stuck with classical a bit longer. I couldn’t resist revisiting another recording reviewed in the September issue, Spunicunifait’s Mozart: 6 String Quintets on Historical Instruments (24/192 WAV, Alpha/download). Soundstaging and transparency were quite good, the air surrounding the ensemble gratifying, and every instrument and color was highlighted and flattered. I was in bliss. Then I played the August issue’s maximally transparent Recording of the Month, Rachel Podger and Brecon Baroque’s Just Biber (DSD128, Channel Classics/download), on which Podger’s baroque violin exhibited an ideal amount of edge. More bliss.

In the Adagio from Mahler’s Fourth Symphony, performed on period instruments by Les Siècles under the leadership of François-Xavier Roth (24/96 WAV, Harmonia Mundi/download), bass notes were in tune and nicely (if not perfectly) well-defined. Credit is also due to recently installed room treatments from Artnovion, which complement previously installed treatments from A/V RoomService, Stillpoints, and other companies.

Time to burst out of the ghetto and into Boris Blank and Malia’s “Celestial Echo” from Convergence (16/44.1 FLAC, Boutique/Qobuz). This track has quickly become a show favorite, for good reason. With the Jubilee pre and the rest of the system, the artists’ electronically manipulated soundstage was all-encompassing. The bass was jaw-droppingly powerful though not the fastest or tightest my system can produce. I cannot claim that the presentation in my moderate-sized listening room equaled the huge soundstage and bass I heard from the massive Magico M9s, four D’Agostino Relentless amps, and more top-level equipment in a huge, two-story room at AXPONA 2025. But on a smaller scale, Malia and forces seemed to fill every inch of my space.

I continued on a bass kick. On the long version of Aretha’s “Bridge Over Troubled Water,” remastered in 2021 and issued on the compilation Aretha (24/96 FLAC, Rhino Atlantic/Qobuz), the midrange sounded gorgeous and smooth. What a joy.

Choosing among other tracks on Tom Fine’s “Bass Test” playlist on Qobuz (footnote 8), I cued up “Ratchets” from Hedegaard’s Inferno (24/44.1 FLAC, Spinnin Records/Qobuz); “No Sanctuary Here” from Chris Jones’s Roadhouses & Automobiles (24/44.1 FLAC, Stockfisch Records/Qobuz); “Honky Tonk Women” from the Stones’ Forty Licks (24/96 FLAC, Polydor/Qobuz); and one of my standbys, “Electrified II” from Yello’s Toy (24/48 FLAC, Polydor/Qobuz). In every case, bass was weighty and impressive, and highs were notably less aggressive than I’ve heard them on my system at other times, in other auditions.

One of the last pieces of music I visited was Dominique Fils-Aimé’s “Birds,” a track from her superbly recorded album Nameless (24/88.2 FLAC, Ensoul Records/download) that’s played so often at shows that its first notes sometimes tempt me to flee from demo rooms (footnote 9). But this time, I sat still. I heard far more intimate detail than I’ve heard at any audio show, which is not unusual. But there was something more: a midrange beauty amidst the expanse of sound that invited me to nest rather than fly. That, my friend, is an accomplishment.

Comparisons
On one level, it’s unfair to compare the $42,000 hybrid Octave Jubilee to two more expensive solid state preamps, the $150,000 D’Agostino Relentless and $77,975 Soulution 727. But when a preamp that costs much less than either of those impresses me this much, those supposedly “unfair” comparisons help underscore how much the Octave can deliver.

The Relentless has an astounding ability to unravel the most complex orchestral passages. It masterfully delivers stunningly strong and maximally fast bass, large and convincingly weighty images, perfectly defined leading edges, a massive and completely open soundstage, remarkable transparency, and a kaleidoscopic range of colors (footnote 10).

One of my go-to torture tracks is the second movement of Shostakovich Symphony No.11, “The Year 1905,” on Andris Nelsons and the Boston Symphony Orchestra’s live recording of Shostakovich Symphonies Nos. 4 & 11 (24/96 FLAC, Deutsche Grammophon/Qobuz). Stunningly captured in Boston Symphony Hall by Nick Squire (with assistance from Joel Watts and John Morin) and mastered by Tim Martyn of Phoenix Audio, the recording’s bass and detail are exceptional. The Relentless is the only preamp I’ve reviewed that can untangle every colliding line in this musical massacre with aplomb and without adding more noise to the ruckus. It holds nothing back, fires every breathtaking bass wallop right at your gut, and rules in its extraordinary range of colors and silence between notes.

The Octave Jubilee communicates much of what the Relentless can, with bass that’s timbre-true and impactful, a midrange whose mellowness draws you in, and highs whose leading edge is softer. Its bass is almost on a par with the Soulution 727’s. Where the Soulution excels is in the upper regions, where its additional silence and clarity, utterly refined presentation, bloom, and ability to convey complex timbral nuance and shading sets it apart. Its soundstage is also wider, and its overall presentation a bit warmer and more transparent.

Ultimately, music is more than a checklist of attributes or transitions from a major third to a minor fourth. It’s about feelings, and that which lies far beyond and above the realm of words and measurements. On that score …

Let us sing its praises
Listening to music through Octave’s flagship Jubilee hybrid preamp left me grateful to be alive. Even if music in the Celestial Spheres resounds with a magnificence that dwarfs anything we can experience here on Earth, our time in the physical body is far more bearable when reproduced music sounds so inviting and wonderful that it transcends the confines of four walls, mental chatter, and the body itself.

Some will point to the Jubilee’s tubes and declare, “See, that’s what tubes can do!” Others will praise its lack of negative feedback, its outboard power supply, and the considerable gifts of its designer, Andreas Hofmann. Me? I’m content with the mystery of not knowing. Like any fine work of art, the Octave Jubilee hybrid preamplifier transcends the sum of its parts. I can’t imagine anyone with a heart, soul, and love of music who would not want to partake of its riches.

Specifications

Description: Zero feedback, hybrid (tube/solid state), two-channel preamplifier with external power supply and remote volume control. Optional discrete Stepped Attenuator (47 Position, 0.1dB channel matching) volume control and HT bypass. Tube complement (4×) ECC82 (12AU7). Balanced input with input transformer, Ground Lift. Inputs: 2 pairs balanced (XLR), 4 pairs unbalanced (RCA). Outputs: 2 pairs balanced (XLR), 2 pairs unbalanced (RCA), 1 pair unbalanced Monitor/Tape (RCA). Frequency response: 3Hz–100kHz, ±1.5dB. Input impedance: 2k ohms balanced (XLR), 100k ohms unbalanced (RCA). Output impedance: 33 ohms unbalanced (RCA), ~66 ohms balanced (XLR). Maximum output voltage: 8V. S/N ratio: >90dB on high gain, >98dB on low gain. Low, 10dB/17.5dB (RCA, Gain Low/High), 16dB/23.5dB (XLR, Gain Low/High). THD: 0.1% @ 3V/7.5k ohms. Power consumption: 60W.

Dimensions: 17.2″ (435mm) W × 6″ (152mm) H × 19″ (480mm) D for preamp/8.7″ (220mm) W × 6″ (152mm) H × 19″ (480mm) D for PSU. Weight: 38lb (17.2kg) preamp/25.4lb (11.5kg) PSU.

Finish: Silver or Black with choice of stone or wood inlays: slate, granite, or on request, jungle stone, birch, walnut, or makassar burl.

Associated Equipment

Digital sources: dCS Varèse five-piece music system, dCS Rossini CD/SACD transport; EMM Labs DV2i DAC, Meitner MA3 Integrated DAC; Innuos Nazaré Music Server and PhoenixNET network switch; Small Green Computer Sonore opticalModule Deluxe (2); Broadcom/Avago AFBR-5718PZ 1GB SX-SFP Gen-5 fiberoptic modules (2); Nordost QSource linear power supply (2); Sonore Audiophile linear power supply; Synology 5-bay 1019+ NAS with Ferrum Hypsos linear/switching hybrid power supply; ASUS AX6000 and RT-AX88U Pro mesh routers and Netgear Nighthawk modem; 2023 Apple iPad Pro and 2025 MacBook Air.

Preamplifiers: Dan D’Agostino Relentless, Soulution 727.

Power amplifiers: Dan D’Agostino Momentum M400 MxV monoblocks, Accuphase A-300 monoblocks.

Loudspeakers: Wilson Audio Specialties Alexia V with Acoustic Diodes, Wilson LōKē subwoofers.

Cables: Digital: Nordost Odin 2, Valhalla 2 (USB and Ethernet), Frey 2 (USB adapter); AudioQuest WEL Signature, Wireworld Platinum Starlight Cat8 Ethernet; OM1 62.5/125 multimode duplex fiberoptic. Interconnect (XLR): Nordost Odin 2 and Blue Heaven (subwoofer), AudioQuest Dragon. Speaker: Nordost Odin 2, AudioQuest Dragon. AC: Nordost Odin 2, Valhalla 2; AudioQuest Dragon and Firebird; Kimber PK10 Palladian. Umbilical: Ghent Audio Canare on NAS; QSource Premium DC cables with Lemo terminations for QSources.

Accessories: Grand Prix Monza 8-shelf double rack and amp stands, 1.5″ Formula platform; Symposium Ultra Platform; Nordost 20A QB8 Mark III, QKore 1 and 6; Titanium and Bronze Sort Kones, Sort Lifts; Stromtank S-4000 MK-II XT power generator, SEQ-5 Audio Distribution Bar; AudioQuest Niagara 7000 and Niagara 5000 power conditioners, NRG Edison outlets; Environmental Potentials EP2050EE surge protector/filter; Wilson Audio Pedestals; Artnovion Lagos and Alps diffusers and bass corner traps; A/V RoomService Polyflex diffusers; Resolution Acoustics room treatment; Stillpoints Clouds (8); HRS DPX-14545 Damping Plates; Marigo Aida CD mat.

Dedicated music room: 20′ L × 16’4″ W × flattens at 9’4″ H.