Cayin HA-300B Mk. II

HA-300 MKII has been built again as a Class A single-ended triode amplifier to preserve the all-important even-order harmonics audio enthusiasts crave from such topologies.

But Cayin's flagship remains a truly reference device. The direct-heated magic from Genelex PX300Bs – bearing the Gold Lion mark of quality – continues to provide Cayin with access to square law, load line and graceful soft-clipping triode functions at the drawing board to push down distortion without the crutch of negative feedback. 

HA-300 MKII's high tube operating voltage ensures excellent open-loop linearity and additionally reduces the need for negative feedback.

Clean power is supplied by a physically separated power supply built around a massive toroid. A choke input in tandem with a huge smoothing capacitor locks stable, quality, DC power in place without sag, post 22DE4 tube rectification. Indeed, power supply regulation is thorough, extending beyond typical small signal regions to encompass even the power stage and high-voltage sections of the amplifier.

Huge EI-core output transformers with reinforcing shielding are wound in-house to Cayin’s exact spec for frequency extension at the extremes, lowering impedances and providing immense inductance for the lowest bass reproduction, plus great top-end transparency owing to their shape.

Custom-built AudioCapX MultiCap coupling capacitors upgraded for MKII's signal path are also ideal for passing low frequencies and extending bass down to 10Hz. Phase reproduction in the audible human hearing range remains stellar as a result, with taut dynamics and impactful slam – not the wooly affairs of yesteryear's transformer amps.

That high bandwidth gets delivered into any working personal audio transducer, with HA-300 MKII's output transformers allowing it to drive low-impedance, low-sensitivity planar-magnetic headphones balanced via 4.4mm and 4-pin XLRs pushing up to 6 watts on the front.

That potent Class A power can even be switched to speaker terminals on the rear to drive high-impedance, high-sensitivity passive speakers from the likes of Rogers, DeVORE Fidelity or Zu Audio. What's crazier is this brute in ballet shoes produces next to no hiss into sensitive earphones via 4.4mm ... a true feat, barely imaginable, till this point.

There is therefore almost no scenario in which you can't enjoy this HA-300 MKII behemoth. Or, employ a different Cayin specialist that you can browse here, and view all our other amplifiers here.