The JLH Gateway-- A Golden Jubilee Tribute

 Questions of Class-A -- 'Pure' and Otherwise         After the previous post that surveyed a slew of class-A amplifiers, and then some, many a question has been raised by class-A enthusiasts and DIYers.           Quite natural that they hinged on class-A and its merits. But more questions were raised about higher power amplifiers that 'claimed' they were class-A designs. Many readers were flummoxed by claims of class-A power going all the way up to nearly 100 Watts, and that too in small, light packages; they wanted to know if it was really "pure class-A watts". Questions and doubts galore, mostly triggered by the hyped and honeyed ad copy and reviews in glossy hi-fi mags. Forget about 'respectable' brands playing such misleading games; even designers have, so sad to note, got onto the bandwagon with a big 'CLASS-A' banner on it!           Do we really have the 'garden-variety' class-A, and the pristi...

 Playing Musical Chairs ...           Playing musical chairs with a medley of class-A amplifiers is a tantalizing, thrilling prospect. Basically the game is a metaphor for deciding the winner by elimination, and most agree that there is no better fun game than musical chairs to zero in on Numero Uno. Here is an opportunity (and a challenge!) for the class-A enthusiast to play musical chairs with a set of class-A amplifiers, including the all-time favourite the JLH Classic! The winner, as they say, takes it all!! ... with the Many Flavours of Class-A           Naturally, the decades since the JLH Classic amplifier appeared on the scene in 1969 have spawned a profusion of class-A amplifier designs. But then you might think, what are these designs by other designers doing here in a site devoted to JLH and his classic amplifier ??           As many a diehard JLH enthusiast would put it (based on t...

The P-N-P Pandemic !           The audio scene, just like the fickle fashion scene, is prone to trends and fads that surface with some regularity out of the blue. One such trend/fad that gained some traction around 2015 or so was the 'P-N-P Fever' -- every (not exactly true...but still!) JLH fan and DIYer was swearing by the 'sound' of a JLH Classic implementation with PNP transistors in the output. And the Chinese kit retailers made good money out of old stock devices or fakes or whatever. Their lack of knowledge of English stood them in good stead, as nobody expected an instruction manual or even a circuit diagram-- it was just a PCB and some parts and sometimes even a fairly good cabinet and some average heatsinks -- but all bundled at an unbeatably low price! In all honesty, I must admit that some kits with old Sanken and other respected brand 'audio transistors' offered good value for money for the hobbyist who knew his ropes well.      ...

The Master's Voice ...  and More           Building the JLH Classic amplifier takes quite a bit of artistry in that one must judge the 'musicality' of the amplifier -- a factor that its designer had set much store by. For JLH the designer, engineering concepts were only the means to achieve 'subjective truth in amplification'. But of course, he was not a pure subjectivist; nor was he fully in the 'objective/measurements' camp. As he easily walked the middle ground, we could see that  his genius and artistry lay when, with aplomb, he blended the art and science of amplifier design. Half a century (and more!) has passed since he had given the world his 'simple' amplifier, but still it continues to exude audio truth as he had envisaged.           Over the past decades, especially after the passing of the great man, questions and doubts of the JLH enthusiasts and builders were answered largely by a dedicated few, who them...