Review: Vinnie Rossi L2 Signature Preamplifer and L2 Signature Monoblock Amplifiers (Part 1)

Oftentimes, hifi gear that immediately impresses is not what you want. The same can be said for many things we encounter in life so we’re talking about common sense.

When something immediately impresses in hifi, it typically means that a specific aspect of reproduction stands out, whether that be bass, resolution, pace, warmth, etc. Like anything flashy, once the newness wears off, things can seem a bit shallow. And shallow is the last thing you want from music reproduction. Here, as elsewhere, we want deep.

Vinnie Rossi’s L2 Signature Preamp and amps represent the flagships of the Vinnie Rossi line. They are the best on offer from the company. The L2 Signature Preamplifer is a modular component, where you can add a DAC and/or a Phono Stage. While the unit under review includes both options, for Part 1 I am focusing on just the Preamp as I’ll be leaving the DAC and Phono Stage review for Part 2.

At the heart of the L2 Signature Preamplifier is Vinnie Rossi’s latest Class-A, ultra wide bandwidth, DHT topology powered by patented Belleson super-regulated, dual mono linear power supplies.

Directly Heated Triodes (DHT). Just the words, especially when coupled to zero-feeback (and there is none in the L2 Preamp), make some men weep with the promise of sonic ripeness. Vinnie employs a pair of DHTs in the L2’s Preamp but not in a conventional way seeing as they are the only tubes to be found in the L2 Preamp. Owners can bypass the tube output stage by flipping a few internal toggle switches which switches to a JFET output stage (which is configured as a unity gain buffer) but why would you? Really? The L2 Preamp ships with a matched pair of Electro-Harmonix EH300B Gold Grid tubes. You can also swap in other DHT variants including 2A3, 45, 300B, PX4, 101D, 205D, and SV811 with the flip of the filament voltage selection switch located around back.

I typically don’t refer to specifications for a few reasons—I have no way to verify the manufacturer’s claims, they are often fairly meaningless in terms of overall system performance, and some people tend to place way too much importance on them. With that being said, I will mention that the stated signal-to-noise ratio (SNR) for the L2 Preamp is -120dB with the EH300Bs (and I trust what Vinnie says). What this means is anyone who believes that tubes add noise to a circuit has just been proven wrong. Granted, you have to go to some lengths to make that happen. For example, those nice looking mesh tube cages are not just there for aesthetic or safety reasons, they connect to AC ground eliminating hum. Frequency response with the stock EH300B tubes is 2Hz – 500kHz (+/- 0.5dB), 0.5Hz – 950kHz (+/- 3dB) which explains the “ultra wide bandwidth” statement in the above-quoted blurb.

photo credit: Vinnie Rossi

There are number of custom Belleson super-regulated power supplies inside the L2 Preamp for supplying “ultra-quiet linear voltage regulation” for those DHTs and the optional DAC and Phono modules, Yamamoto solid Teflon UX-4 tube sockets, a discrete, 64-step resistor ladder volume control using Pickering silent signal relays, and the whole thing sits on a “solid, precision CNC machined aluminum isolation base with Stillpoints ULTRA MINI feet.”

All told, you could be thinking something along the lines of—that sounds like the best of the old and new—and I wouldn’t blame you.

Here’s Vinnie Rossi on some of the design highlights of the L2 Signature Preamp:

The L2 Signature Preamplifier is a dual-mono, directly heated triode (DHT) design.  As far as I know, there has never existed a preamplifier quite like it. My design approach was to, a) Use only one 4-pin, directly heated triode (DHT) per channel, and b) Provide the ability to easily change the filament voltage, allowing for the use of what I believe are some of the finest sounding triodes of past and present day: 300B, 2A3, 45, PX4, SV811, 71A, PX-4, T-100, and 101-D/205-D.

This is a pure, class-A topology with no driver tubes, no output transformers, and no feedback.  The triodes do not have to work hard to drive the load of a loudspeaker (as they are more commonly used for in an SET amplifier) so they will last for many years.  Depending on the tube used, you get in the ballpark of 6 to 9dB of voltage gain and exceptionally wide-bandwidth.  The volume control implementation is a custom stepped attenuator type using reed relays to switch through a resistor ladder.  There are also balanced input and output stages, as well as provisions on-board for the optional L2 DAC and L2 Phonostage modules.

Using these particular triodes in a linestage is not common because it is quite challenging to achieve such low noise with them.  The internal, shielded power supplies and 4-layer PCB use Belleson super-regulators, complicated grounding techniques that took me a long time to develop and perfect, and careful routing of highly sensitive traces within ground planes.

The stock L2 Preamp offers 1x active balanced (XLR) and 2x single-ended (RCA) Neutrik inputs and 1x active balanced (XLR) and 1x single-ended (RCA) Neutrik outputs. There’s also a pair of Trigger Out connectors to cable the L2 Preamp to the L2 Monoblocks so that the included chunky aluminum remote works everything. Nice. The solid, CNC-machined aluminum chassis was designed by Evette Design Group and Vinnie and to my eyes it has a serious, sturdy, and industrial look and feel commensurate with the asking price. The machined aluminum knobs for input selection and volume are big and chunky and have a very nice precision feel to them with just enough tension to let you know the L2 Preamp is no pushover.

The L2 Signature Monoblocks offer 75 W (into 8 ohms, double that into 4) of Class AB MOSFET power, a custom-wound, 500VA toroidal power supply transformer, Neutrik RCA, XLR, and 12V Trigger input jacks, and a matching solid, CNC-machined aluminum chassis design by Evette Design Group and Vinnie. The L2 Monoblocks also sit on solid, CNC-machined aluminum isolation bases with Stillpoints ULTRA MINI feet.

photo credit: Vinnie Rossi

Of course, the L2 Monoblocks are designed to sonically mate with the L2 Preamp and it’s interesting to note that their use of feedback compliments the L2 Preamp’s zero-feedback design. Yin meet yang.

Here’s Vinnie on the L2 Signature Monoblocks:

The L2 Signature Preamplifier is the heart-n’-soul of the electronics chain, while the L2 Signature Monoblocks provide the muscle. They take the preamplifier’s signal and give it the power to drive a wide variety of loudspeakers with a very linear, ultra-wide bandwidth output stage that uses only two MOSFETs (no paralleling up on output devices here). The goal was to make sure they had all the finesse and subtlety needed to tango with the L2 Preamplifier without adding sloth or a typical solid-state signature. So while you don’t get hundreds of watts from them, what you do get is a highly responsive and resolving circuit that is nearly as minimalist in its approach as the L2 Preamplifier. The power supply in each L2 Monoblock use a custom-wound and potted toroid transformer with a DC-blocker circuit in front of it, soft-recovery diodes, and very low-ESR capacitors.

The L2 Preamplifier and Monoblocks (along with the L2 DAC and L2 Phonostage) are by far my finest designs in the last 15 years. I plan to “trickle down” a healthy portion of both of them into my upcoming L2 Integrated Amplifier (L2i) designs, which will be in production in September and hopefully will be ready to show at RMAF 2019!

photo credit: Vinnie Rossi

The L2 Signature components are now available in black or silver. All of the L2 Signature components travel in their very own custom military-grade hard travel case. Very nice.

The system in-use for this part of the L2 Signature review consisted of the totaldac d1-streamer (see review) and totaldac d1-seven DAC while the DeVore Fidelity gibbon X handled the power-to-music output.

The Vinnie Rossi L2 Signature system goes deep. Way, way deep into the music. The overall presentation is rock solid, super stable, squeaky clean and precise coupled with a full boded and rich but not over-ripe sound. There is nothing flashy about the L2 system’s sound, which is as it should be when it comes to good hifi, especially hifi you plan to live with and use for the long term. Marry, if you will. Mated to the totaldac stack and DeVore gibbon X, music filled the barn with as full a spectrum of sonic delights as I’ve heard, making each listening moment something special, turning music reproduction into a production worthy of complete and total attention. I know “complete and total” are redundant but they felt more accurate in conveying the depth of the experience when used together than either standing on its own.

The L2 system made my DeVore’s sound like new speakers, capable of things hereto only imagined. Bass response in particular was better than I’ve heard from the Xs and by “better” I mean in every meaningful way which includes tone, body, weight, and impact. The sound image completely decoupled from the speakers, filling the barn with stereo-defying presence in every dimension. Sounds picked, plucked, strummed, and sung sprung from all over the damned place like a sonic fireworks display. At the same time there was a tactile sense of the subtle, a caressing of micro-detail and nuance, allowing time and timing to create tension and release, the stuff that turns hifi into a moving musical experience. Balancing and delivering all of these traits is, in my experience, something special.

I’ve only recently discovered, OK “found”, Umm Kulthum which is troubling seeing as she is known as “The Voice of Egypt”,  “Egypt’s fourth pyramid”, and sold over 80 million records (I just bought the remastered LP The Twinkling Star so you can make that 800 million and 1). The Voice of Egypt is powerful and emotive nearly beyond belief and I found myself hitting the Up arrow on the L2 remote’s volume control which brought Umm closer and closer still. This record, Voice of Orient, streaming from Qobuz is not a great-sounding record but a) that doesn’t matter, and b) it doesn’t matter because the L2 + my system doesn’t get digital harsh or digital edgy. So a not-great recording just ends up sounding more like a recording, kinda flat and less dimensional, than a good recording which sounds more like music. However the essence of the music, its core tenets, remain intact and on display with a power and presence that allows full entry to the music of Egypt’s fourth pyramid.

Princess Nokia joins Show Me The Body on the track “Spit” from the band’s Corpus I for a wonderful mix of sweet and sour—Nokia’s vocals riding atop the band’s badass bass and electronic grit and the L2 combo offered up the full palate. I enjoyed my way through most of my 10-hour playlist which includes music from all walks of life including Aldous Harding, Buffalo Daughter, Jimi Hendirx, Nina Simone, Throbbing Gristle, Mal Waldron, Swans, Parliament, Butthole Surfers, Aretha Franklin, Giacinto Scelsi, Jordi Savall, and more. All of it was rendered with tender loving care by the L2 Signature components in my system, from the biggest, boldest, badassness, to the quietest, subtle beauty and everything in between.

As is my wont, I also played lots of music that’s new to me streaming from Tidal and Qobuz including some brandy new favorites. Regardless of where my mood and music traveled, the Signature L2s acted like the world’s best world-worn roadies, packing and unpacking every last bit of everything packed into each recording.

The Elrog Effect

Owners of tube audio gear know well the joys of rolling—with a simple swap, we can shift the sound output. Since every single solitary piece of hifi gear is voiced, i.e. it has a voice, you can think of tube rolling as a user-based voicing option. Vinnie sent along a pair of Elrog ER300B tubes ($1,479.95/matched pair) to try out in the L2 Signature Preamp in place of the stock Electro-Harmonix and I am glad he did because I preferred the Elrogs by a long shot so they remained in the L2 Preamp for the majority of the review period. The basic differences the Elrog’s brought to the party included increased dynamics,  a more incisive sound, and greater timbrel richness. Music sounded more alive, more lit up, and more colorful.

Bruuuuuuuuce!

With the L2s + my system, music was more menacing, more fleshy, and more fleshed out than I’ve heard from my Leben CS600 integrated. Of course that’s hardly a fair comparison seeing as the Leben retails for less than half the price of either L2 component. I am also putting together a system of separates for reviewing and enjoyment purposes consisting of a pair of Mytek Brooklyn Amps ($2495/each) and the Rogue Audio RP-1 Preamplifier ($1699). While still much less costly than the L2 Signature components, this system offers some aspects of the L2 sound namely in terms of bass response and that overall sense of control. It falls short, however, when it comes to the fully-fleshed-out fleshiness of the L2s. Which raises an interesting question—where does the Vinnie Rossi L2 Signature magic lie? In the Preamp, the amps. or the combo?

I can’t really answer this question in a meaningful way because these comparisons are limited to the gear I have on hand. What I can say is that the L2 Signature Preamp with a bi-amped pair of Mytek Brooklyn Amps (300W/each ) delivered a fair amount of the L2 combo while the Rogue RP-1/L2 Monoblocks fell further short. While the Brookyln’s offered a similar grip on the music all the way down low, the L2 Signature Monoblocks provided more flesh on music’s bones, a greater sense of texture, and a more open and relaxed sense of the space of the recording.

We could get into “what if” scenarios along the lines of what if I used another preamp more in line with the price of the L2 or an amplifier(s) more in line with the price of the L2, but that could on forever. To my mind, if you’re serious about buying into the Vinnie Rossi L2 Signature line, you’ll want to go whole hog. Why? Because they’re made for each other. If you are on a budget that doesn’t allow for the whole pork enchilada, I’d suggest starting with the L2 Preamp.

The Vinnie Rossi L2 Signature Preamplifier and L2 Monoblocks clock in at $32,990 for the set. That’s some serious money and there’s an entire world of wonderful products out there that fit into and under that amount, way too many for one person to listen to, let alone review. To help narrow the field, you’re also buying into a company, a philosophy, and a sound so I’d suggest getting to know Vinnie Rossi through his website and an in-person audition of the L2s. If that means some travel to a hifi show, so be it. The cost and time are well worth it considering the investment.

I’ve been following Vinnie Rossi’s hifi products going on 15 years and I am happy to see, hear, and report that he has arrived at the deep end of the pool with a truly satisfying splash. Coupled with my source and speakers, the Vinnie Rossi L2 Signature components offered some of the most musically satisfying sound I’ve heard in the Barn. Bravo!

Stay tuned for Part 2 of this review where we’ll talk about the optional Phono and DAC modules.


Vinnie Rossi Signature Preamplifier
Price: $16,995 | Phono Module + $3495 | DAC Module + $3495

Vinnie Rossi Signature Monoblocks
Price: $15,995/pair

Vinnie Rossi
800 Main Street
Suite 125
Holden, MA 01520
USA
Phone: +1 (774) 234-0800
Email: info@vinnierossi.com
Business Hours: 9am to 5pm, EST
Monday – Friday