Monrio is a small Italian House that in several years of activity won a reputation for its high-quality devices. Products currently range from stereo integrated amps to 1, 2, 3 and 5-channel power amps, a stand-alone phono stage, a DAC and a CD player. Other products coming. Videohifi has already tested two integrated amps: the 55+55W Asty and the 80+80W MC-207.
Just after the latter test the boss of Monrio, Mr. Gazzola ("Monrio" is just the acronym of Monte Rio, birthplace to him), told me he was working on a tube preamp specifically aimed at driving solid state power amps.
In these days hybrid amps are rather fashionable and I am among those who believe the best way to pursue a good result is getting a tube pre plus a solid state power amp (high quality integrated amps do exist too, anyway).
So I immediately booked for a test unit, but project development took a bit longer than expected. For instance, the House had to design a dedicated, one-cm. (0.4") taller brand new cabinet to better host standing 6922 tubes since a horizontal accommodation would not have met factory’s tight standards.
But one day I was called back to learn that an Asty Line Mk II pre was ready to travel to my house, and what follows is my story with it.
The device and its ergonomics
The Asty Line Mk II comes packed in an average-quality but effective carton including the preamp itself, a good manual and a rather cheap mains cord. A volume-only remote control is also included at no extra price; mine was a pre-series piece so you won’t find it pictured here.
For what concerns safety, we can observe the cabinet bears no sharp edges or tips and its heathsinks are narrow enough to resist to curious pets and babies (unless they are allowed to sneak nails or blades right into daddy’s gear!). Mains cord and cables get securely fit and even after having worked long this Monrio gets just mildly warm. It is CE (European Community)-certified.
Even though it is present in several different countries, Monrio Internet knowledge base in forums and discussion groups can’t obviously match those of large, historical brands. But this manufacturer readily answers to incoming e-mails: when I was testing their MC-207 I dropped them a mail with a couple of questions, without detailing who I was. Well, I got a full answer in less than one day. Monrio website is rather complete.
This ampli shows a very good passepartout design with a thick, well-finished, matt-silver front panel bearing three big knobs, an LED and the IR receiver eye. No need therefore to disguise this device, it can flaunt from its shelf and win a good WAF (the always feared Wife Acceptance Factor).
The three sturdy, screw-fixed knobs that are lathe-turned from solid metal blocks are the only controls on the front panel. They are finished with a transparent, rubber-feeling paint that allows a good grip. The two on the left side control the input selector and the volume (very difficult to make out their position from your sofa); the power switch has been made with the third of these expensive paperweights (a delayed switch-on circuit is present). An off/on LED completes the controls set. Rather obviously, no headphone jack is available.
The rear panel bears a good-quality connectors set for four high-level inputs, a tape loop, twin outputs to power amps and an IEC mains socket. No phono stage, even upon request (Monrio manufactures a stand-alone phono pre).
The double line output is an uncommon feature and it’s very remarkable since it adds, to the usual single-power amp configuration, the opportunity to drive two power amps in passive biamping. In such layout, each amp receives a full-range signal from the preamp and delivers power to the loudspeakers whose crossovers do the frequency filtering.
Furthermore, one may use one output to feed his/her power amp and the other one for a headphone amp.
Interiors
The Monrio Asty Line Mk II Pre is a totally (both general and local) zero-feedback tube preamplifier whose hearth is one 6922 twin triode by Sovtek.
This tube is probably the most widely used in line and phono stages by hi-fi manufacturers; first names I can recall include Audio Research, Sonic Frontiers, Conrad Johnson, Audible Illusions, Convergent and, coming to Europe, Danish Copland and Italian Pathos.
Technical qualities of the Sovtek enhanced 6922 are its gain (over 30dB), its high operating tensions and its low output impedance. Another very important feature, vital in pre and phono stages, is its exceptionally low sensitivity to microfonic feedback so that this tube is actually vibration-free thanks to its sturdy interior structure and its very good glass processing. Sovtek 6922s deliver a very smooth and balanced sound but don’t lack transparency and verve, either.
The preamplifier case is made of two 2mm (0.08"), U-shaped panels that clamp together (iron bottom and aluminium top). Damping fabric strips stick along panels’ contact areas while twelve steel screws hold the whole unit closed. The front panel is made of a further 1cm (0.39") aluminium plate fixed against the chassis vertical extension.
The outcome is a rock-solid, definitely vibration-free case knocking on which one gets almost no resonance: a definitely friendly environment for a tube. Four rounded, metal feet that couple the Asty Line Mk II to the surface it’s sitting upon complete the fight to vibrations.
The manufacturer told me feet might be three only in the next pieces in order to make the unit even more stable and vibration-free.
All circuitry is fitted upon two large boards.
One bears the ITT-Canon input selector, the ALPS Blue series RK27 potentiometer (both shaft-operated) and its remote control circuitry.
The other bears the split power supply sections and all of the line stage circuitry and, of course, the 6922 tube standing on a ceramic support.
This preamp is an example of rational layout; the only signal-leading wires are the four, two-inches long Kimber Cable bridges that link the two boards.
Power supply section is based upon a toroidal transformer that could feed any mid-size power amp and that for better efficiency has got one secondary winding for each required voltage.
In order to more easily serve the tube (and intake less hum), the AC/DC rectifiers are diode-bridges instead of the tubes one could expect. Caps and diode bridges are split for each circuit branch (so-called "distributed capacity and bridges layout").
Components list is really a first-class one: a Panasonic TSU 10,000uF with four Schottky-type diodes filter filaments tension; two 100uF Samwha caps and super fast diodes filter the high-tension supply to the tube. The FET input stage relies on a Kendeil 2,200uF cap with its own diode bridge; it is fully transistor-stabilised and independent for each channel as above. In the anode electric supply, electrolytic caps are limited to first stage only then we find caps such as polypropylene MKP Audyn Cap and MKP ICEL.
Other caps are electrolytic ELNA for filaments stabilising stage, while output line stage sports Mundorf Silver Oil series caps.
All ground circuitry is connected to a single ground star centre.
Upgrade, tuning
Tube: once warranty will have expired, you may contemplate swapping your Sovtek 6922 for some other tubes (no bias tuning required).
Suitable alternatives for this device include JAN Philips and cheaper E88CC Tesla (JAN stands for "Joint Army and Navy", i.e. military-grade supply).
You’ll possibly gain something in warmth and "tube-style magic" especially with the Philips, but you will also lose something in accuracy on the other hand. JAN Philips is credited to be a bit noisier than Sovtek and both, especially the JAN Philips, tend to be more microfonic.
Hence, being the Sovtek outstandingly carrying its duty out in this device and being also first manufacturer’s choice, I wouldn’t frankly replace it.
Placement and vibrations: I noticed no significant difference placing this Monrio on the marble floor of my listening room or atop a rack. As I was explaining earlier, significant attention has been paid to make the Asty Line Mk II an almost vibration-free device so no further effort is required on this side.
Feet and spikes: soft, de-coupling feet did not perform well, spikes did not bring any significant improvement either: that means manufacturer has done good job against vibrations. You can peacefully let it sit on its factory metal feet set (mind shelf surface for possible scrapes if it’s not quite hard)
Mains filters and power cord: as I said above, this Monrio bears outstanding filtering sections; neither a mains filter nor a shielded power cord made a significant difference in my set-up (though I’d use a thicker cord).
Performance
As I was saying, this preamplifier has been developed to well match solid state power amps, though vacuum tubes devices are obviously welcome as well. And this is an interesting feature for those of us that are after hybrid amplifications.
So I put the Monrio in the place of my 2016 Galactron preamp, to let it drive my two Galactron 2016 Class-A, mono block power amps. Please notice that this three-piece set has specifically been designed to match high-sensitivity speakers just like my Klipschorns and that it’s linked through dedicated balanced interconnects made by the same factory. That means that taking the place of the preamplifier in such an optimised system is a hard task to carry out.
My first observation is that the soundstage is surprisingly tall and deep, and large enough. But what really surprised me was the ability of this pre to scan all different soundstage levels in a three-dimensional way: each instrument is placed at its very location with proper dimension; proper space is left among them. The image is kept definitely stable with no hesitation under any condition, better than the reference pre. I guess the attention paid to a clean current supply and to vibration prevention must have had a role in this.
The Monrio pre showed both a remarkable extension in the bass range and the ability to keep it under control, better than my reference, precious when driving bass-generous solid state power amps. Mid frequencies are a tube pleasure for their presence, realism and absence of distortion; both male and female voices came out with full presence. Highest frequencies are shining as they are supposed to but never become sharp or glassy. In a word, the Asty showed a very good overall timbre with a slight preference for (not prominence of!) the bass range.
Very low noise and fine micro contrast help general dynamics, being the macro dynamics more of a power amps family business: but you need a clean and fast input signal for that, and this preamp does deliver it. Good ability to describe each single instrument among a symphonic tutti, but my solid state pre is sharper at this game.
In this framework of overall timbre correctness and dynamic ability, what comes out is the huge amount of detail that the Asty Line Mk II can effortlessly deliver. In a word it combines the sound richness of a tube amp with the precision of a solid state, slightly in favour of the first (it’s a tube device after all!). The amount of music detail is definitely high though this happens with no euphonic attitudes or timbre coloration.
With tube power amps I got the same high level performance; a KT-88 push-pull proved to be a very good mate for this Monrio but other solutions would be fit as well.
I have to say that making an unfortunate match with this Monrio is very difficult.
In order to get the luckiest one, just avoid speakers (and power amps) that do not control the bass since the Asty Line Mk II is not a shy guy in that range; on the contrary, it can add that touch of magic to rigorous but cold systems. No matching problems on the source side either; in order to get the maximum performance I’d go for a rhythmic and open player and, needless to say, for turntables / heads having the same timbre.
All these features melt together in the most meaningful performance for a music machine: hours of listening with no fatigue and a large flow of rhythm and music.
Conclusions
When I started my tests I hadn’t seen the price tag of this device yet.
I carefully avoided asking to be free of any influence but I came to the idea that, according to its quality and performances, this preamp would be quite an expensive item.
Then I discovered it was definitely not so expensive.
Prices may vary depending on local currency, import taxes and other costs so please refer to your local representative (listed at Monrio’s website) to know the exact retail price in your own country: I bet you’ll be happily surprised.
With its construction level, connection abilities, components set, circuitry layout, outer design and - above all - with its performances, this rock-solid preamplifier can only be strongly recommended.
It takes source input and processes it to deliver to power amp (amps if biamping) a correct, musical, rich signal: exactly what a good Orchestra Conductor is supposed to do with his musicians…
Via Rosselli, 34 - 29100 Piacenza, Italy
Tel. +39 0523 716156 - Fax +39 0523 461455
The Monrio Asty Mk II has been tested with (main devices):
Philips DVP 9000S player
Galactron Mk 2016 pre XLR-connected to power amps
Galactron mono block Mk 2151 Class A, 50W each power amps
PrimaLuna Prologue Two AB tube (KT-88) integrated amplifier
Klipsch Klipschorn speakers
van den Hul 102 Mk III, Galactron GC-2703 XLR and DIY interconnect
DIY power cables
BlackWire power cords
BlackNoise mains filter
Optimised Electricity supply line
Live end / dead end, 35 square metres ca. listening room.
Room acoustics tuned with DaaD (TT-like devices).
Software (most used only):
"Scheherazade", Telarc CD
Freddy Cole, "Rio de Janeiro Blue", Telarc Jazz DSD CD
Rebecca Pidgeon, "Retrospective", Chesky SACD
Takeshi Inomata, "Ex Spiral", New Sonic Dimension XRCD
Arthur Rubinstein, "Chopin 19 Nocturnes", RCA Red Seal CD
Pink Floyd, DSOTM, EMI SACD
Framba, "Musica romantica per organo (Organ romantic music)", SicutSol CD
