Flying under the radar…
By Roy Gregory
Sometimes, you can capture the character and quality of a component with a single album, a single track. In this case that album is Steve Earle’s debut, Guitar Town (MCA MCF 3335), but it’s not the jaunty, toe-tapping insistence of the title-track (so beloved of Linn/Naim demonstrators) that encapsulates this listening experience: it’s the quieter and far more reflective ‘Someday’, with its wistful, almost plaintive lyric and plangent melody. Yes, there’s the rhythmic grasp that instils the trip-hammer beat into tracks like ‘Guitar Town’, but here it underpins the slower pace, the low-key vocal and the carefully crafted arrangement, bringing a sense of purpose and direction to the presence and building the musical density that makes the track so powerful and gives it such emotional impact. This is a sound of body and colour, balance and pace, dynamic and temporal control. This is a sound with real musical substance. It’s a sound that hits home. This is classic Class A sound, without the pinched, spot-lit staging of so many solid-state iterations, or the blousy vagueness that afflicts so many Class A tube amps.
Is it the best of both, rolled into a single, all-conquering solution? In some ways and for some listeners the answer will undoubtedly be, “Yes!”: but (as usual), dig a little deeper and it’s not quite that simple. Yes, this is a hybrid solution (in every sense) but it’s also distinctive and a world away from the tube in/Mosfet out norm – technically, sonically and musically.
When it comes to the audio world, hybrid is a word with a long (and distinctly chequered) past. There are hybrid systems, such as tube pre-amps used with solid-state power amps, the Audio Research SP8 or 10, mixed with the early Krell amps being perhaps the most famous example. Then there are hybrid products, amplifiers that mix solid-state and tubes within a single chassis, or loudspeakers that mix active and passive elements or different driver technologies (for instance, electrostatic panels with moving-coil bass drivers) in a single speaker system. Yet, despite the attractions of combining complimentary attributes, more often than not, mixing technologies creates issues of continuity and occasionally, reliability. The DC generated by tube pre-amps on switch-on/warm-up could be famously destructive when connected to DC coupled amps like the Krells, while for hybrid amplifiers, like the Counterpoint SA20 and ARC D125, staying alive often seemed to be a daily struggle. Even those products that succeed in working consistently – like the Martin Logan hybrid electrostatic speakers – all too often suffer from musical confusion rather than a ‘best of both worlds’ outcome.
But you’ll note that these examples are largely historical. More recently, there have been a number of genuinely ground-breaking hybrid loudspeaker systems, like the Göbel Divin series, or the Vandersteen Model Seven and Avantgarde Trio G3, with part-active solutions becoming more common since the arrival of high-quality DSP systems to aid integration. But when it comes to amplification – and power amps in particular – there have been far fewer offerings, as designers grapple with the incompatible electrical demands that arise when mating tubes and solid-state. Any successful solution demands a new and different approach, not just a mix-and-match cocktail with a hint of optimism. Circuit blocks need to be understood in terms of and selected for function rather than technology. A truly successful hybrid approach depends on a systematic rather than aesthetic view point: what benefits come from a given technology in a given system location – and what needs to be done to actually realise them?
