EAR Yoshino 869 - Tube Integrated Amp
Building on the success of the EAR 859 with increase power output and better control of operating conditions irrespective of valve parameters and age. When it was launched in the early 1990s, originally as a kit offered through Hi-Fi News magazine and subsequently as a regular EAR product, the EAR 859 integrated amplifier caused quite a stir. Why?
Because it was designed by Tim de Paravicini, the man who almost single-handedly started the so-called valve renaissance in England. After over a decade’s successful production of resolutely push-pull amplifiers (principally the noted 509, 519 and 549 models), the 859 was Tim’s reaction to the developing trend towards low-power single-ended triode amps, his statement that: ”Yes, of course I can do that, and I do something a bit different at the same time.”
Accordingly he completely bypassed the ‘conventional’ circuits, most of which use classic valves such as the 300B, 211 or 2A3, and based his design on his long-standing favourite output valve, the EL519. As conventionally connected that valve is a pentode, but Tim’s contribution was to invent a new connection which operated it as a triode, a connection he dubbed Enhanced Triode Mode, or ETM for short (the name highlighting the analogy with Enhancement Mode MOSFETs). Normal triode-connected pentodes have the screen grid connected to the anode, but Tim turned things upside down and connected the control grid to the cathode, using the screen grid as the input. This turned out to give better linearity, higher power rating and much better reliability than alternatives, and the 859 went on to become a classic amplifier, winning plaudits throughout the world. Its sound, a blend of the classic valve virtues of clarity and openness with modern low noise and freedom from ‘mush’, clearly set it apart from the competition and it has had a longer production run than almost any other such model.
However, there’s nothing that can’t be improved – and if anyone could improve the 859 it would of course have to be its original designer. Hence the 869: the basic output topology of the 859 with a slightly revised output transformer, plus a modified input stage with one extra small-signal valve. This has allowed a small but significant increase in output power to 15W per channel, and even better control of operating conditions irrespective of valve parameters (meaning better consistency as valves age or are replaced). In sound quality terms, this means, in essence, the same but better and more of it, for longer.
In addition, in response to customer requests, the input options have been extended so that the amplifier can be used as a power amp, bypassing the selector switch.