MasterSound Piccolo
Not so long ago reviewers all over used to wine about lack of suitable loudspeakers for those half a dozen of watts delivered by single-ended (triode) tube amps. Apart from a handful of horn speakers there were none. The solution was to recommend dynamic speakers with higher than average sensitivity, typically in the range of 90-91 dB, and hope for the best. Then widebandwidth speakers started gather popularity, and the worst days of SET amps were over. Today the situation is much better: horn speakers loom large, and high sensitive loudspeakers are not rare at all.
But who would have believed that one day interest in single-ended amplifiers comes from the computer world. But here we are. Computer speakers are typically listened in the near field and therefore need not be overly sensitive in order to produce enough volume even with small power single-ended amplifiers.
The Italian Mastersound Piccolo is one such amplifier. The fact that it sports only two line inputs tells a lot: for example, one for the CD and the other for a USB-DAC. Piccolo outputs 6 watts from a single EL84 per channel. Note that Piccolo is not a single-ended triode (SET) amp: EL84 is a true pentode, and in the Piccolo the tube is not triode-trapped.
In the push pull mode two EL84's would have given easily 10 to 15 watts, and the amp would've had much wider applicability. In that light going for a single-ended configuration with only one EL84 at the output is quite a radical and respectful choice by Mastersound. Not unique though. Almarro and couple of other manufacturers have launched similar single-ended EL84 amps in recent years.
Piccolo is a zero NF design. The manufacturer says that NF was not needed because of their own, especially for Piccolo designed power transformer. The transformer is also said to guarantee an extended frequency response. The power tubes are autobiased. Output transformers have 4 and 8 ohms taps for different speaker loads. The input/driver tube is ECC802.
With wooden side panels and the aluminium shelter for the tubes, Piccolo looks quite cool. Compact and stylish. Distinguished. It looks like an audio object that is not meant to be hidden in a rack. But is it too good-looking to be taken seriously?
Mastersound recommends a 10 min warming period for the tubes to stabilize, and based on my listenings, I'd recommend that the recommendation be taken seriously. During the review Piccolo behaved well and as expected. Two points though. First, Piccolo gets hot, really hot. Even the volume knob feels hot on the finger tops. The fact that the OPTs are inside the chassis has no doubt something to do with this.
Secondly, the scale of the pot is quite special: with a normal line-level input rotating the knob just a little produces high volume of the sound, indicating a high gain level. The input sensitivity is 1V. The same happened independently of the loudspeakers, sensitive or less sensitive. There may be other reasons to avoid less sensitive speakers with the Piccolo (eg. dynamic limitations at peak points of the music) but with a majority of speakers I'd say that shortage of the volume should not be a problem. More importantly, despite its voluminous sound, Piccolo didn't sound messy. Music had calmity, stability and sensibility.
It was clear that sonically Piccolo cannot be regraded anything but a tube amplifier. It was clear because like many other tube amps - SET or not (like my PP 6V6 amp) - Piccolo was able to bring certain "inner life" and livelyhood to to the sound and music as well as a kind of stretched 3D soundstage. All those properties are, in my experience, less frequent in transistor amps (my 120W Sony for example). And I don't care if this is due to a double dose of second harmonics or what. The effect is there and at least to my ears always equally welcomed.
Wadia 151, a 20W Class D design with an inbuilt DAC as the only input, was quieter, more polished and cleaner (eg. violin sounds), and stronger in the bass. But Piccolo sounded more spacious, more 3D, more heterogenous, varied and sophisticated.
What most prominently disntinguished the Piccolo from true SET amps with a triode output tube was its slightly thin upper midrange and energetic treble presentation. As if the extended frequency response was made to be heard. The somewhat overtoned sound was vivid and airy and transparent but didn't have the bloom and mellowness of true SETs.
Despite its limited dimensions the little Piccolo showed surprisingly manley authority over music. The attacks were quick, almost too sharp. Many music proceeded rapisly and rhytmically. Grand orchestral music thundered without slowness. At higher volume levels the tone of the sound begun to harden, and assume stony shades. EL84 is not the nastiest tube when it comes to overdrive distortion but I see no sense in torturing the Piccolo with its last watts.
At the bottom end, the Piccolo was slightly bass shy and asphyxiated. Not only the double bass came out not as luscious as it could have, but male bass voice was affected too. And this independently of which speakers I used them with (Dynaudio monitors, Dunlavy Athenas, my AGA horns etc.) When the two - clear, forward and extended treble and slightly gentle bass - are put together it seems to me that Piccolo requires time and carefulness in choosing right loudspeakers, those that are sophisticated and suitably soft in the treble, and correctly supported in the bass. That should do it. Once loudspeakers fit for the purpose are found the tonal balance will hit home, and all the good qualities of the Piccolo will even better emerge.
Mastersound Piccolo was an interesting new acquaintance. My feeling is that it will easily occupy some market niche where good-looking, good-sounding tube integrated amplifier is needed. Unlike the Almarro 2050A, which I would not as an integrated amp even though it has a volume pot (excellen as a power amp), Mastersound Piccolo is a throrughbred integrated both functionally and sonically.
Mastersound Piccolo, c. 1800 euroa