Jean,
I gave up looking for those Zeners for the time being and ordered 25 more from Mouser.
They are so cheap that the postage was twice what the diodes cost.
I will eventually find my own large stash of Zeners, so if you could use any just drop me a note and I’ll send you some free gratis.
Note: I misquoted the voltage in my prior post. The Zeners should be 5.1 volts at 1 watt.
The following is what my friend Emailed me in September: “Most of the AA5’s and AA6’s use cathode bias in the output stage which consists of a 150 to 250 ohm resistor from cathode to ground, which yields an average bias of 5 to 6 volts. You can clip out that resistor and replace it with a 5.1 volt, 1 watt Zener diode which will make the bias completely stable at 5.1 volts irregardless of how hard the output stage is driven, or at what volume level the set is playing. Connect the banded end of the diode to the cathode and the other end to ground and you will definitely hear the difference.”
Eric S.
