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GUIDO CORONA'S SYSTEM

LOUDSPEAKERS Vienna Acoustics The Music (reference)

ELECTRONICS
Jeff Rowland Design: M925 430W monoblocks (reference), M725 330W monoblocks, M312 500W stereo, Criterion linestage (reference); Audio Research Ref 3 linestage

SOURCES
TEAC Esoteric X-01 Limited

CABLES
Aural Symphonics: Chrono XLR ICs, Chrono speaker wires, Magic Gem and Ultra Cube XXV power cords; Cardas Golden Reference speaker wires; Audioquest Sky XLR ICs.

ACCESSORIES
Nordost Sort Kones (TC, AC, BC).

 

Positive Feedback ISSUE 68
july/august 2013

 

 

merrill audio

Veritas Amplifiers

as reviewed by Guido D. Corona

 

merrill audio veritas amplifier

Introduction

Let me start with a bold statement: the 400 Watts Merrill Veritas monoblock amplifiers deliver an enchanting and majestic sound. Through Merrill Wettasinghe's almost Hippocratic preoccupation to the sound purity of their minimalistic design, which harnesses the enormous potential of the underlying Hypex Ncore NC1200 modules, Veritas have achieved an extraordinary level of performance for any high power amplifier, regardless of technology, topology, or class of operation.

Electronic Engineer Merrill Wettasinghe, founder and president of Merrill Audio Advanced Technology Labs, did not launch the Veritas design project with the preconceived goal of creating an amplifier based on the new Ncore technology. Rather, he intended to design an amplifier that would yield superior sound. Never the less, after evaluating in depth an NC1200 developer prototype amplifier from Hypex, he selected the Ncore NC1200 module and its companion switch mode power supply (SMPS) as having the greatest potential to yield the purest sound to the Veritas project. "I could do a lot with it", Merrill asserted in an extensive phone interview with the author.

Wettasinghe's constant mantra is audio purity. His goal ever remains to keep the signal path as short as possible to achieve musical Neutrality. "This is very neutral sound", he explains. "It is not cold. It is very musical, not clinical. Rather, it is very nice and accurate. Of course, it will play whatever is in the recording: thus garbage in garbage out. If you have a bad source, it will show it up. Veritas will not cover up a bad source signal."

The amplifiers are aptly named after the ancient Roman goddess VERITAS—the incarnation of truthfulness: Veritas was the mythological daughter of Saturn—god of time, and was mother of the goddess Virtue. Merrill confesses that—as he aims to sonic purity—his creations cannot please every audiophile, nor he is attempting to do so. "I will continue to develop products in this [my] fashion", he reminds me. He seems to imply that seekers of ultimate euphony may not be satisfied with Veritas inherent lack of preferential attention to any particular sector of the audio band. While, at the other end of the audiophilic spectrum, those ultimate seekers of sizzle may not be enthralled by Veritas's insistence in delivering natural transients without artificial emphasis of leading edges.

merrill audio veritas amplifier

Technology

Merrill's attention to detail starts with each satiny black hard-anodized aircraft-grade Aluminum chassis. The units feel and look substantive: they weigh a full 35 Lbs each, and are based on a full width 17-inch module. These are assembled from interlocking blocks of milled aircraft-grade aluminum billet, where pockets housing individual component parts have been carved for optimal acoustic, mechanical, and RF isolation. According to Merrill, the choice of metallurgy, the almost one-inch thick walls and internal braces, as well as internal component segregation pockets, contribute to minimize microphonics and transfer of vibrations into electronic boards, component parts, wires, etc…. Some more exotic Aluminum alloys might have made the chassis too rigid for optimal sound. With an excessively rigid chassis, "you introduce other problems. [Generic aircraft grade Aluminum] is still easy to machine and is rigid enough, and you need to allow some mechanical absorption into the chassis." Then Merrill continues: "The chassis is also heavy and isolated enough so that it will not transfer microphonics into the boards. If any microphonics originates inside a board or component part, it will not be transferred out of the isolation pocket."

To minimize the propagation of any mechanical vibrations, all Boards mounted onto the chassis are dampened with yet unspecified dampening materials interposed between them and the chassis. Merrill declines to reveal the nature of these dampening materials and techniques. He explains instead that a mechanic dampener is unlikely to solve the complete problem, but painstaking mechanical dampening combined with other techniques is likely to yield significant audible results. "If you address a problem with 10 different methods and each method affords a 1% improvement, in the end you have a 10% enhancement, and that is a huge thing in the audio world." He declares.

The painstaking quest for audible results continues with the choice of footers and stock power cords. Merrill explains, "All footers have mechanical responses and sonic effects. Some footer may sound more musical to some listeners, but actually introduce more ringing into the system. We want more isolation instead, so that there is less contamination from other components into the music." Thus, Veritas are not equipped with common compliant footers. After focus groups experimented with a number of footers from a variety of manufacturers, Merrill decided to include a full complement of six Stillpoints Ultramini risers with each monoblock pair.

The designer believes that Veritas deserve power cords commensurate with their level of performance: instead of the usual non-denominational stock power cords, the amplifiers are shipped with high quality custom cords designed and manufactured by Triode Wire Labs. These exclusive cords (part number MA-10) feature cryo-treated 10AWG pure copper conductors.

Instead of the momentary contact switch used by other manufacturers, the Veritas power switch is a welcome half-height pushbutton, which emits a soft blue glow and remains depressed when the amp is operating. Surprisingly, the switch does not grace the front panel, but rests under the chassis, just behind the front plate. Merrill explains that on production units, the front wall became almost one inch thick, and the presence of a center brace forced the eventual move of the power switch to the bottom. The bottom location offers several advantages: while the blue LED in the switch is dimmed as much as possible, from under the chassis its glow is further absorbed and dimmed before reaching the user. Moreover, the switch can be operated with just one hand, fingers clamping the top of the 3-inch thick chassis, and thumb operating the switch at the bottom, without running the risk of the device sliding back on its polished footers and so flying off the equipment rack with less than enjoyable results.

Veritas supports bi-wiring with twin Rhodium-plated solid Copper patented Cardas binding posts on each chassis, because Ncore NC1200 modules are inherently designed for bi-wiring, and sport twin output leads in parallel on each module to enhance current flow to the speakers. Merrill reports that in audio testing, the bi-wire configuration offered audible advantages over single wire runs. He reports "A little more strength at the bass lower end and a little cleaner at the top end." I was skeptical… but, was I ever wrong, as discussed later in the article!

Cardas binding posts have been selected to achieve best possible contact between speaker wire and amplifier board. Heavy 11Awg multi-strand litzed Cardas output wire soldered to the NC1200 output leads bore into the hollow post all the way to the post's very end, beyond where the spades actually connect. The Cardas posts are manufactured from solid soft annealed Copper billet: They establish a huge and very strong contact surface with the spade connectors of speaker wires. Admittedly, bananas are easiest to work with, while Cardas posts may be a little fiddly to connect. However, the latter yield an amazing connection quality, because a good spade connector yields a much larger surface to connect than a banana, and therefore a much more robust connection, which secures a better signal.

XLR input connectors are Cardas as well, featuring silver pins that penetrate all the way through to short Cardas 19AWG multi-strand litzed signal input wires, which are soldered onto them.

A gold-plated Furutech 15A grounded IEC power connector, and a 12V remote trigger complete the connectivity lineup. According to Merrill, Furutech IEC connectors were chosen because of their excellent contact quality. He points out that 20A IEC connectors would have been overkills, as Veritas are fused at 8A through Synergistic research fuses. In these premium fuses, conductive micro-grains are processed with a Tessla generator that induces a 2-million Volts potential. The Tessla device realigns or polarizes the microcrystalline structure of wires through the electromagnetic field generated by the voltage pulse. According to the Veritas manual, this process, referred to by Synergistic Research with the charmingly misnomered tradename of "Quantum Tunneling", improves the openness and precision of the sound stage.

As soon as the device is connected to the AC, the SMPS1200 power supply initiates a soft power up cycle, which is completed with the signal output stage on mute. The SMPS gradually increases in-rush current at power-up, until desired voltage values are reached and are stable. Only then, a relay switch is automatically activated, and power flows to the Ncore NC1200 power conversion module. Control logic monitors any anomalies. If any value is detected to be out of bound, the information is flagged back to the SMPS, which shuts down the unit.

Audio purity is the guiding principle that underlines the entire design, and the selection and execution of every component part. No internal or external interference is allowed. Sonic improvements are achieved one component part at a time.

Merrill explains, "Veritas uses a differentially balanced design with floating inputs. In differentially balanced designs, there is only one single circuit, just like in a traditional single ended design, but the topology accepts a hot and a cold input phase, and subtracts from the input the noise common to the two phases, resulting in a much quieter noise floor than on single ended designs." He asserts that differentially balanced circuits are much preferable to symmetrically balanced circuits, where unavoidable fluctuations within tolerances of pairs of component parts, and other imperfections, prevent theoretically identical circuits to mirror each other perfectly on opposite polarity.

Veritas avoids exotic solutions and custom active circuitry. Rather, it utilizes minimalistic passive solutions that the designer has found to facilitate purity of sound. For example, the amplifier avoids heavy dielectric wire shielding that may introduce dynamic-slowing capacitance, and would alter the sound in a variety of ways. Instead, the signal path is kept as short as possible, served by internal Cardas wiring: ultra-soft annealed and urethane-litzed multi-strand copper that is painstakingly soldered point-to-point for an optimized linear frequency range. "The sound is smoother with annealed copper than with hard metal", Merrill explains. "Hard metal contains internal micro-fractures that distort the signal. Even with annealed copper things can go wrong: it is important to minimize bending of any wires, lest micro-fractures are introduced and distortions can start to creep in."

Even the Merrill logo—laser-etched at the top of each chassis, and replicated in miniature onto the front plate, bespeaks Merrill's attention to detail: two identical sinusoids 90 degrees out of phase represent the letter "M".

Unpacking

The Veritas monoblock amplifiers were delivered sturdily double boxed: protected from mechanical mishaps by soft foam inserts. Instead of the usual plastic bag, each chassis was sleeved in a handsome and heavy brocade cloth sack, shimmering in ever-shifting deep purple hues. Oddly, while the protective sacks appeared to feature a channel to accommodate a hefty drawstring, no drawstring was provided.

merrill audio veritas amplifier

Each Triode Wire Labs MA-10 power cord was loosely inserted between foam inserts. Stillpoints Ultramini risers were packed in individual pouches, and one red plastic miniwrench was provided to fasten the risers to the bottom of each chassis. Unfortunately, I found the red plastic tool flimsy to the point of being useless: I opted to forego the Ultraminis all together, and soon rested Veritas on top of the excellent Nordost Sort Kones

Break-in – The Path To Music

It is easy to like the Veritas monoblocks. In fact, they evolve into sonic appeal so rapidly that one might be tempted to reach premature conclusions, which would unfailingly underestimate an amazing performance potential, which progressively blossoms throughout the first 1000 hours of operations. Moreover, the performance of the amps can be further tuned and enhanced through the choice of placement, mechanical supports, and connectivity.

Initially, I connected the amps to my 20A dedicated line using the supplied MA-10 power cords. Thus, in an admittedly non-orthodox fashion, I rested one chassis on a trio of Aluminum-Ceramic (AC) Kones, on top of a 2-inch thick granite slab in reach of the dedicated outlet. Gingerly, a fresh trio of Kones was placed on top of the first amp, with the second chassis neatly stacked onto these.

The system was mostly wired by the wonderful loom of Aural Symphonic wires, which I reviewed in PFO Issue 67. Aural Symphonics Chrono XLR Ics connected the amps to the Rowland Criterion linestage. A single run of Chrono wires fed The Vienna Die Muzik speakers. The stock Triode Wire Labs MA-10 supplied power to the amps from the quad receptacle of my dedicated outlet.

The break-in process lasted 8 weeks. An old NAD radio tuner fed Veritas with quasi-white noise from FM interstation hash during nighttime, as well as whenever I was not actively listening to the progressively enchanting music making.

As early as the sixth hour of operation, the underlying authority of Veritas became apparent on large symphonic transients, while a faint mist still seemed to pervade a largely two-dimensional stage, and a lack of low level harmonic suggested a sense of slight dryness. There was no harshness to the mid-treble region so typical to brand new amps, but an exceedingly faint high treble Burr, which may be unique to non-broken-in Ncore NC1200 modules, seemed to intermodulate each note in a manner that was more curious than disturbing.

By the thirtieth hour, the treble Burr as well as the initial haze had faded away into inaudibility. Music was remarkably clean, but harmonic content remained lean. Resolution seemed to be limited to the broader strokes, and low-level information was still scarce.

By the 50th hour, while the opening low brass chorus in the second movement of Antonin Dvorak's New World Symphony conducted by Leonard Bernstein with the Israel Philharmonic (DGG Redbook) still showed some hollowness and a paucity of harmonics, Veritas started to assert its remarkable ability to contain treble intermodulation. As already discussed in my Aural Symphonics review, the first movement (Allegro Moderato) of Dvorak's string sextet with double bass Op. 48, performed by Members Of The Berlin Philharmonic Octet (Philips Classics) is a sonically challenging affair, where the rising and growingly dynamic harmonies of the pre-thematic cadenzas tend to induce electronics and cables alike to generate strident intermodulations. Yet, stridency was already starting to abate, and would eventually vanish completely by the end of break-in and setup optimization.

A mixed bag of sorts marked the 75th hour, where pleasing low-level harmonics gradually started to fill instrumental images, while a suddenly excessive midrange warmth and mid-lower bass overhang were eventually mitigated through four full days of FM hash diet.

The 175-hour mark was a landmark. Stage proportions, image sizes, and authority had surpassed those of my 500W Rowland M312 stereo amplifier. Moreover, Veritas exhibited significantly more coherence on orchestral fff than M312: the chordal tutti at the conclusion of the first section in the New World Symphony 2nd movement acquired a solidity, which was progressively approaching what I would call "unflappable authority". The opening low brass chorus had lost its harmonic hollowness and was temptalizingly evolving into a full-bodied growl. Clearly Veritas were starting to blossom into a powerfully charming adolescence—an adolescence graced by a growing subtlety and low level detail, which could be appreciated in the quiet interplay of asynchronous bowing changes of high mass strings in the softer passages. Previously hidden ambient cues and faint creaks, suggestive of the pianist operating within a three-dimensional stage, appeared in Inna Poroscina's piano performance of Dvorak's dynamically intense miniature "In the Old Castle" (Brilliant Classics Redbook). Treble intermodulation in the Dvorak sextet was receding below what the $16,000 M312 was ever able to control. In the New World Symphony, the bass line was almost foundational, with just a hint of residual pastel. The plucked double bass in Diana Krall's Temptation from The Girl in the Other Room (Redbook Verve) was sweetly pitched with a touch of warmth.

Approaching 500 hours of music making, Veritas produced a grand stage with impressive authority, with but a slight shadow to mar ultimate clarity in the bass region. The youthful imperfection was confirmed in the Dvorak string sextet, where the double bass still showed traces of a dark and pillowy uncertainty. On the other hand, air around instruments and coherence of treble texture were becoming remarkable: I perceived one of the least amounts of treble intermodulation of any amps that ever graced my system. Only a faint sign of glassy hardness in the highest notes in the arpeggios of Poroscina's piano reminded that Veritas might not have achieved full maturity yet.

Musical Maturity

Approaching 800 hours, the pillowy uncertainty in the bass is morphing into a clean and well pitch rendering. A question arises: are residual and marginal imperfections a function of the amps, or might they be caused by compromises of connectivity and placement? Perhaps some adjustments are in order: the amps are unstacked and moved side-by-side on top of a 2-inch thick solid African Mansonia wood shelf—a family heirloom for the last sixty years. The Aluminum-ceramic Sort Kones (AC) are replaced by the more sophisticated Titanium-ceramic variant (TC).

Results are instantly evident: the stage and images are most open and concrete yet. The low brass chorus assumes further body, texture, and depth. Finer detail emerges from the asynchronous bow changes of massed high strings. The introduction to the Dvorak sextet is almost free from treble intermodulation, while only the faintest residual brittleness can still be detected in high mass strings.

Soon the stock power cords are replaced by a pair of Aural Symphonics Magic Gem: traces of hardness on the sextet introduction become difficult to detect. The new world Symphony is powerful and emotionally engrossing. The stage is magnificent in the three dimensions. Instrumental images have a concrete body with a perception of living space around them. The low brass section has grit and gravitas in fanfares and tutti. Harmonic interplay in woodwind is finally generating that rare ghost intermodulation felt in the middle of my cranium, which is not an artifact of the reproduction equipment, but is a psychoacoustic effect possible only with the purest of reproduction. Veritas are now so revealing that the sound of breathing of a youthful Jean-Pierre Rampal in J. S. Bach's sonata for solo flute in G-minor BWV-1020 (CBS Classics reissue) is more than suggestive of the master flautist in his prime of life magically standing between the Vienna Muzik speakers.

Veritas reach a stunning milestone at the 1000 hours mark: all minute traces of intermodulated treble hardness have disappeared from my test tracks, leaving a completely congruent presentation across the frequency spectrum, from low bass through high treble; from pianissimo to crashing fortissimo; from the sextet and from the chordal tutti in the New World Symphony.

merrill audio veritas amplifier

The fff high treble of Jan Garbarek's soprano and tenor saxophone improvisation on the Hilliard Ensemble's performance of the Gregorian chant Regnantem Sempiterna on Officium (Redbook EMI) is sweet and exquisitely emotional. In the nuanced subtlety of the work's quiet moments, I follow Garbarek deliberately feeding back into the church's acoustics, and sustaining the natural reverberation of the recording space by modulating his breathy airflow. The solid presence of the instrument is enchanting in its feathery delicacy.

A Final Step: Bi-Wiring

A fresh reading of the Veritas manual reminds me that the amps may be further enhanced by bi-wiring. As the Muzik speakers are terminated with one single set of 5-way binding posts, and their banana sockets are already in use, bi-wiring requires a minor act of ingenuity. I fasten the standard size spades of my pair of Cardas Golden Reference speaker wires to the second output posts of the Veritas amps, and secure the oversized spades at the other end to the speaker input posts. (It should be noted that Guido is not in fact bi-wiring his speakers, but for lack of a better term, "bi-wiring the amplifier" to the single-wire speakers as suggested by Merrill via the amplifier's dual outputs. Perhaps "shot-gun" might be better applied here. The use of Cardas Golden Reference was simply based on not having another pair of the Aural Symphonic cables and should not be read as a comparison and/or preference of either in this application - DClark, Editor.). The result is an instantaneous nimble gravitas: the authority of the introductory low brass chorus in the second movement of Dvorak's New World Symphony stuns me with positioning in space, textured growl, breathing of players, resolution of individual voices, and the crisp cuivre of the tenor trombones on the fff climax of the section. There is no trace of hardness in the sextet, nor in the symphony's woodwinds and massed high strings. The plucked bass in Krall's Temptation has assumed foundational coherence while maintaining its musical sweetness; Krall's elocution has perfect clarity and shows no traces of stressed sibilants. The illusion of Jean-Pierre Rampal on flute, Trevor Pinnok on harpsichord, and Roland Pidoux cello, performing Bach in front of me is uncanny for its realism. Only a marginal shyness from ultimate harmonic complexity, such as in Pidoux's basso continuo on J. S. Bach's sonata in A Major BWV-1032 for flute and cembalo, subtly reminds me that Veritas are priced well under $30K: the marginal lightness of harmonic exposure across the frequency spectrum, from deep bass through high treble, may be detected only by direct contrast with a few amplifiers in significantly higher price bands.

Conclusions

With his minimalistic approach of complementing the new class D Hypex Ncore NC1200 module and matching SMPS1200 power supply with an essential complement of painstakingly chosen passive components, with his meticulous attention to isolation detail, and a an almost Hippocratic commitment of doing no harm to the music, Merrill Wettasinghe has created an amplifier of superior sonic and musical performance. Veritas have a remarkable ability to generate a stage populated by solid images, of yielding a wide frequency extension that remains consistently musical, of creating an immersive neutrality with no traces of clinicality, an astonishing imperviousness to intermodulatory fatigue, an authority and transient behavior which combine naturalness with speed, and a singular ability to reach into the subtle filigree of micro detail.

Veritas is a member of a small but growing family of amplifiers based on the new exciting Ncore technology designed and patented by Bruno Putzeys of Hypex in the Netherlands. Because of the amplifier's conservative implementation, I wonder at the extent that its undeniable magic may be influenced by the performance potential of the underlying NC1200 module. Purely from a pricing point of view, Veritas stands towards the middle of the current entry-level Ncore NC1200-based monoblock lineup: at $12K, Veritas is priced between the $9K Acoustic Imagery ATSAH, and the almost $16K Kaluga by Mola-Mola. It is worth pointing out that I have not yet examined nor evaluated these two competitors of the Veritas monoblock: hence, I shall not venture any hypothesis about their relative sonic, engineering, and price-performance merits—nor how I might eventually rank my own preference among the three.

The Merrill Veritas monoblock rests at the vanguard of a new performance paradigm in high power amplification—regardless of technology and class of operation. Veritas performance transcends any stereotypical subset of audiophiles, prefixed by competing technological qualifiers: be these lovers of solid-state amplification, or the militant wing of tubed audiophiles. Hence, let me restate for the record: the Merrill Veritas is a magnificent high power monoblock amplifier for lovers of music… It will deliver an enchanting and majestic sound for discerning audiophiles of every stylistic and technological persuasion. Guido D. Corona

Specifications

Power: 400 Watts / 8 ohms, 700 Watts / 4 ohms, 1,200 Watts / 2 Ohms
Input Impedance: 90 kOhms
Output Impedance: 3 milli Ohms
THD: 0.004% at 200 watts
Current: 38 amps typical max
Frequency Response: 0Hz - 50kHz 0/-3dB
Gain: 26dB
S/N: 128dB
Inputs: 1 XLR Balanced
1 Remote Trigger. 12V for remote turn on/off
Outputs: 2 pairs of speaker binding posts for bi-wiring
Dimensions: 17" x 12" x 3" without footers
Weight: 35 lbs (per chassis).

Veritas Amplifiers
Retail: $12,000

Merrill Audio Advanced Technology Labs, LLC
80 Morristown Road, #275
Bernardsville, NJ 07924
(415) 562-4434
info@merrillaudio.net

http://merrillaudio.net

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