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.The input options have also been extended so that the amplifier can be used as a power amp, bypassing the selector switch.
