I have to admit that I've listened to single-ended amps on many occasions. Most of those amps were based on rectilinear triodes – 300В, ГМ70, 845, 211s etc. Despite the mid-range magnificence and incredible musicality they as a rule lacked a proper vigor, a full-blown punch and — even being connected to speakers that had a very good bass response — a bottom end sufficient for playing back live concert. That is exactly why single-ender acquired the reputation of an amp for limited audience —namely lovers of mainstream jazz, opera and chamber music.
But Hercules SE MK II 15th Anniversary (to call it by its full name is a matter of principle now) — is a rare exception to this general rule. Connected to a 145-kilo Magico M3 floorstanders the amp produced such a dynamic sound that I had to ask my S.A.Lab colleague whether we were REALLY listening to a single-ended device. With only 15 Watts of power and at a modest volume level the sound had all the features needed for an adequate representation of any music genre incl. progressive metal and drum-n-bass. And there were no brute force per se: emotional vigor was combined with comfortable (one may even say 'tender') sensitivity in quiet moments and precise articulation of subtle music structure of any particular recording. The feeling of elation, of smooth delivery borders on dense full-bodied sound from the lowest octave to the sparkling silvery twitter. This is that rare occasion when the playback device provokes listeners to replay records that seemed too complicated and too intricate to be interesting. The amplifier's sound is truly captivating for it neither simplifies a convoluted structure (a common flaw among amateur designs), no exerts superfluous brutality — a quality intrinsic to powerful push-pull devices.
«With only 15 Watts of power and at a modest volume level the sound had all the features needed for an adequate representation of any music genre incl. progressive metal and drum-n-bass.»
But the first thing we've noticed — even before the system was properly burned-in — was the incredible stability of the soundstage. No, really: one could wander around the room, stopping even between speakers… still most of the instruments remained in their proper places, only their relative scale changed slightly. Being in the hotspot one could feel both width and depth of the soundstage and also the 3D placing of every single sound.
I must admit that Hercules SE MK II 15th Anniversary is a perfect proof of the fact that the simpler the design is the more profound its implementation should be. A proper single-ender can't be just thrown together — no matter how seductive such an approach may seem. So the 15 lucky ones who get the amp only for 1000 euros are really should be envied.