Magz: Thank you for sharing your midlife crisis design. Looks quite simple in part count 🙂
I had one question which I have uploaded an image for visual aid:
![]()
I assume the suitable "adjustable shunt regulators" look like this below:
![]()
and the other question was about L2. Inductance? I am not familiar with having a coil as a grid leak resistor... what is the unit of that 540 value?
I used a shunt regulator board from K&K Audio in the cathode of the 833. I built a simple regulator for the other one - the schematics are all in the Midlife Crisis thread if you read through it, including the power supplies, which are quite hefty at such high voltages.
There is a lot of stuff in the box when completed! See attached pic of the underside of one amp.
That 540H choke is a grid choke from Lundahl. It gives a very low DC resistance to stabilize the 6E5P operating point while also presenting a high impedance to the signal AC. A bit of a luxury vs a resistor, I admit.
Attachments
@Magz: Ah, thankyou for the pointers! I am going to hunt through your thread
@Hanze Khronye: I did see that one section on R1... but what I am curious about is R11?
@Hanze Khronye: I did see that one section on R1... but what I am curious about is R11?