First made in 1959, this is the best-selling tube amplifier ... standard way of rating amplifiers’ power levels. But the ST-70 has remained popular among vintage hi-fi enthusiasts.

High-end hi-fi shops are full of tube-based devices, and a plethora of tube amplifier kits are available for the electronics enthusiast. Tubes can be bought under a bewildering array of brands ...

The amp’s output stage uses six KT170 valves, which promise high power and low distortion and should have a lifespan of around 3000 hours each. The inclusion of an Auto-bias system should also help ...

Should you open up a high-end linear Hi-Fi amplifier you’ll find ... from an unexpected source could be found in the stereo tube amp that was my youthful folly. It suffered from an appalling ...

The Gryphon has a nicely weighted metal unit that is simply laid-out and responsive. High-end integrated amplifiers don’t tend to be packed to the rafters with features, and this Gryphon hardly bucks ...

Karma-AV is to distribute Unison Research’s high-performance valve-based Hi-Fi separates in the UK and Ireland. The Italian manufacturer’s line-up includes Class A pre/power and phono amplification ...