More Soundtank FZ5 into BMP stuff

[Ben N]

In my continuing quest to make this quasi-BMP useable: OK, so I mapped out the signal path based on Jeff H.'s schematic, finding all the part ##s on the PCB.  There are a couple of discrepancies, about which I have questions.

First, the voltage divider biasing the base of the input buffer on my PCB is not 10k/10k, but 9k1 to 9v and 22k to ground.  Why?  Also, should I change these values if I change the input buffer to a jfet?

Second, between the tone stack and the volume control there is a JFET buffer (Q2 on the board), which is not in the BMP.  Jeff has 510k and 100k as the gate and source resistors, respectively.  Those are the values for the BJT gain stages, but the correct values for the jfet buffer are, not surprisingly, 1M on the gate and 10k on the source.  I assume they put this in in order to minimize insertion loss in the tone stack by presenting a high Z after it, and/or to drive the volume control, which folows the recovery stage in the BMP.  Is this true, and if so,  what should I expect to happen if i just take this buffer stage out, or, following the BMP, turn it into a BJT gain stage (doable, I think, but requiring surgery)?

Finally, Jeff has a 470R series resistor at the output, forming a divider with the 100k to ground.  Mine has a 4.1k instead, and it is actually ahead of the 10uf cap.  I don't think this makes any material difference (right?), but I am just mentioning it.

[Ben N]

bump
this is my last bump--just don't want to get lost in the sauce before someone gets to answer!
Ben