[EdHolland]

Replacement brass caps to replace those lost from a couple of the controlas arrived in the post. Cosmetic work should be concluded soon for a Photo shoot

10 Ohm 1% tolerance resistors are also here, which can be fitted ahead of making any changes to the bias circuit. It will be interesting to see how much current each output valve draws.

Then, on to configuring the IBAM circuitry. I am debating how much range is needed in bias. Ergo, whether to use a multi-turn pot for the whole span of the 22 v supply, or use a pot in combination with a fixed resistor to limit the range of adjustment. This could also be a useful safety feature, as it would prevent (or limit) bias settings that could cause over-current conditions.

Any thoughts?

Ed