After some planning and selling a lot of stuff to raise money, I've started in on my 5f4 build. I decided to use (at least for now) the larger value for the local NFB resistor on the preamp (10M versus the 5f4's 4.7M) to make it exactly like a 5e7, but with two speakers. I can always change that later by adding another 10M, therefore halving the resistance and increasing the NFB to 5f4 levels. I'm still waiting on some parts. The Mojotone chassis came to me with some chrome flaking, and they quickly put a new one in the post. So I've got to wait on that. Also waiting on my Hammond choke that's sufficient to filter the plates. I've populated the board, and I now have a question regarding adding an adjustable bias pot: In the 5f4/5e7 circuit, the bias section is as follows (pics in next post): the junction of the 220k resistors in-between the two .1uF coupling caps goes to the negative side of the 100uF bias electrolytic and then up to the positive side of the diode. I'd like to put a 10kl pot in there, and I'm not exactly sure how to wire it up. I had hoped to use one of those cute little plastic bias pots that I used on a Hoffman-designed build, but I got the turret spacing wrong. It doesn't fit. So now I'm going to use a more traditional Fender-style 10kl pot off the board, but I need to understand better how to wire it.