Solid State Power Amp Reviews

I first encountered Verity Audio's Monsalvat Amp-60 stereo power amplifier ($58,000) in October 2017, in one of the largest single-system rooms at the Rocky Mountain Audio Fest. After hearing the Amp-60 and Verity's Monsalvat Pre-2 preamplifier drive Verity's Lohengrin IIS loudspeakers ($133,000/pair), I enthused about the "most impressive range of colors and supreme sense of spaciousness" that contributed to the system's "absolutely beguiling" sound. A year later, after John Atkinson and I had visited the same exhibit space and been deeply impressed by the sound of a much larger system—in which one Amp-60 drove the two bass towers of Verity's $675,000 Monsalvat speaker system, and two more Amp-60s biamplified that system's main tower speakers—I requested a review sample of the Monsalvat Amp-60.

Amp-60 Whys and Wherefores
After it arrived, I conversed via Skype with the Monsalvat Amp-60's designer, Maxime Julien, and with Julien Pelchat, who, with Bruno Bouchard, cofounded Verity Audio in 1995. "Throughout the years, we rarely heard what we wanted to hear from amps that we paired with our initial products, which were speakers," Pelchat said. "We loved some things about the sound of tubes, but wanted the precision of solid-state and its control of the lower end.

"We decided to go with an amp of our own with much less power, but a power-delivery system that is outstanding. When you design for 500W, you make compromises that hinder the quality of the sound. Being under 100W allows us to go all out on components, with an extremely powerful power supply that can deliver a lot of energy quickly and recharge very quickly. It is less powerful in terms of numbers, but when you listen to it, there is no lack of power behind it."

After Maxime Julien joined Verity, in 2013, his first order of business was to design the Pro-6 preamplifier-DAC-crossover, which comes bundled with the Monsalvat speaker system. From there he moved on to the two-channel Pre-2 DAC-preamp, then to the Amp-60. In naming the new models, Verity looked to composer Richard Wagner, whose final opera had provided the name for the company's first loudspeaker.

"The speaker is fairly small but high performance, so we named it after Parsifal, the Knight who found the Holy Grail by his quality of simplicity," said Pelchat. "At the end of [Wagner's opera] Lohengrin, when the lead character must disclose his identity, he says he was sent by his father [Parsifal] from Monsalvat, the castle of the guardians of the Holy Grail. I love the name Monsalvat. Because it's the castle where the Grail is, you have to reserve it for a very unique product that is not entry-level."

The Monsalvat Amp-60's oversize, "ultra-low-noise" 1.5kV transformer weighs more than 75 lb. High-current reservoir capacitors of low serial resistance and ultrafast rectifiers are integral to a three-stage design whose fully mirrored topology includes components selected and matched by hand.

Within the first watt produced the amp switches from class-A to class-B operation. "Watts are not everything—it's how you deliver the watts that makes the difference," Maxime Julien insisted. "The Monsalvat Amp-60 can drive less efficient speakers with ease.

"The motto of the Monsalvat program was 'Make it happen—Make something that is truly exceptional.' The output section is MOSFET because somehow, when you use them in electronic design, they behave a lot like tubes and require less complicated technology to perform very, very well. You see few wires inside the amp, because I hate wires. Instead, I use a six-layer printed circuit board that weighs over 2.5 lb before things are added to it."

According to Verity, components are precisely spaced and soldered to the board to ensure that signals are always treated the same and that signal paths are kept the same distance from each other to avoid unwanted interference. In addition, layers of "special" insulation limit interference and noise from the Amp-60's AC section. All AC travels under the amp's double floor, and reaches the transformer section isolated from the DC that powers the amplifier itself. The enclosure's heavy, ¾"-thick aluminum panels serve as heatsinks.

The Monsalvat Amp-60's isolation platform, which includes a "special elastomer" that damps floor vibrations, derives from Verity's speaker technology, which eschews spikes for vibration control.

"We found that, depending upon what surface the speaker sat on, its sound changed," Pelchat explained. "It was as though I was hearing energy bouncing up from the floor and coming back through the spikes into the cabinet. To make the speaker as free as possible from vibration, we developed a very special floor-isolation platform using carbon foam, all sorts of esoteric material, and elastomer on each side. Our special carbon-based material works much better than aluminum-based material.

"Once we became very aware of how external vibration was affecting the sound of our speakers, we started to experiment with amplifiers and how different amp stands affect their sound. That led us to develop our amp-isolation platform."

Try as I did via multiple follow-up e-mails, I could get no more specifics from Julien and Pelchat. It was up to my ears to fill in the blanks.

Set-Up
When Paul Manos, of Verity Audio's US distributor, High Fidelity Services, drove to my home to set up a previously broken-in review sample, he delivered it in a sizable red flight case whose two handles per side made it relatively easy for us to carry its 176 pounds. Far more challenging was finding a way to safely grab the amp itself and position it perfectly atop its companion isolation platform (the amp proper has no feet of its own). After lifting platform and amp onto one of my Grand Prix Audio amp stands, it took not much time at all to connect the Monsalvat to my system with Nordost Odin 2 interconnects (XLR), speaker cables, and 15-amp power cord.

Setup was simple. On the amp's rear panel are two pairs of speaker-cable binding posts, one pair per channel; pairs of unbalanced (RCA) and balanced (XLR) inputs, and a tiny toggle switch to choose between them; and the obligatory IEC power inlet and master power On/Off rocker. On the amp's front panel is a slightly concave, barely visible Standby/On button. When a little white LED stops blinking and glows solid blue, you're ready to roll. I always let amps warm up for an hour before doing any serious listening, and prepare them by running Nordost break-in and demagnetizing tones on repeat.

Listening
Other than a very slight buzz through the left-channel Wilson Alexia 2 that was inaudible at my listening position, the Monsalvat Amp-60 performed flawlessly throughout the listening period. "Flawlessly," however, doesn't do full justice to a component that began weaving a web of seduction from the first track I played.

As has become customary since I began reviewing classical recordings for the print and web editions of Stereophile, the first albums I listened to were unfamiliar. As I gave a first listen to our "Recording of the Month" for March 2019, Ibn Battuta: The Traveler of Islam 1304–1377, from Jordi Savall, Hespèrion XXI, and the superb group of instrumental and vocal masters from around the world that Savall enlisted for this project (24-bit/88.2kHz, Alia Vox AVSA9930), I marveled at the natural feel of timbres and the highly detailed, spacious sound conveyed by the Amp-60. Equally impressive was the amp's ability to convey major differences between the acoustics of the two venues in which Savall's forces performed live, and how much more successful the engineers were in capturing bass in the ultraresonant Philharmonie de Paris than in the Emirates Palace-Auditorium in Abu Dhabi. I was so haunted by the final lament at the end of this album that all I wanted to do was turn off the lights, close my eyes, and bathe in the sound.