Hi Tom,
I only mentioned the 5 jacks to clarify the minimum needs for buffer biasing.
I originally wasn't going to bother with biasing ports, more or less for the reasons you mentioned. However, it is becoming more of an issue for me simply because closing up the case radically alters the buffer bias. This is true of the BJT build as well as my MOSFET build, and really it's more important with the BJT build because that circuit is PTC and the bias rises with a closed case. I discovered that when playing with my Steinchen buffers. I'll bet most people running those buffers in closed cases (even with some ventilation) are running them MUCH hotter than they think based on their open case bias measurements.
Even with the MOSFETS, which should reduce bias when the case is closed, the bias levels are so high that I think it is a good idea to be able to easily measure them with the case closed so that any estimates are confirmed. Just MHO. The more I work with the build, the less confident I am in predicting the closed case bias.
I can run mini clips to my test points and out the tube holes, but that forces me to remove the tubes, remove the panels, remove the cover, install the clips, reinstall the cover, reinstall the panels, warm it up for an hour or so, take the measurement, turn it off, let it cool down, remove the tubes, remove the panel screws, remove the cover, remove the clips, reinstall the panels, reinstall the cover, reinstall the tubes, and make sure I didn't swap tubes! Having gone through that process a few times in order to give some accurate biasing advice, it's starting to get old
Just wanted to throw all that out so builders can think about all the nagging issues related to bias ports and biasing strategy. It got me thinking.
Regards,
Neil