EAR 869

The EAR Yoshino EAR 869 is a valve integrated amplifier developed from the EAR 859, with increased power output and improved control of operating conditions regardless of valve parameters or age. Its basic output topology remains that of the 859, while the output transformer has been slightly revised and the input stage now uses 1 additional small-signal valve.

The EAR 859 first appeared in the early 1990s as a kit offered through Hi-Fi News magazine before becoming a regular EAR product. Designed by Tim de Paravicini, it followed more than a decade of production centred on push-pull amplifiers including the 509, 519 and 549. The 859 was his response to the growing interest in low-power single-ended triode amplifiers, using a different circuit approach from the conventional designs based around valves such as the 300B, 211 and 2A3.

Instead, the output stage was based on the EL519, a valve normally connected as a pentode. De Paravicini developed a new configuration that operated it as a triode, named Enhanced Triode Mode, or ETM, by analogy with Enhancement Mode MOSFETs. In a conventional triode-connected pentode, the screen grid is connected to the anode. The ETM arrangement reverses this approach, connecting the control grid to the cathode and using the screen grid as the input.

This configuration provided improved linearity, a higher power rating and greater reliability than the alternatives. The EAR 859 subsequently became a classic amplifier, receiving recognition internationally and remaining in production for longer than almost any other model of its type. Its presentation combined valve characteristics of clarity and openness with low noise and freedom from mush.

With the EAR 869, the revised output transformer and modified input stage provide a small but significant increase in output power to 15W per channel. The amplifier also offers improved control of operating conditions irrespective of valve parameters, providing greater consistency as valves age or are replaced. The result is the same underlying approach as the EAR 859, with increased output and extended consistency over time.

Following customer requests, the input options were expanded so that the EAR 869 can also be used as a power amplifier, bypassing the selector switch.