Mosfet Boost and loop impedance question

[bwanasonic]

I was experimenting with running a mosfet boost in the loop of my amp and didn't get quite the results I wanted. It *felt* a little *stiff*, if that makes any sense. Not real out of whack tonally, but just not quite right. The send impedance of my loop is 560 ohms and the return 10k ohms. I used a 10M resistor for R3 in my mosfet boost. Would a lower input impedance in the boost work better for this purpose? Not really quite sure how impedances react in this situation.

Thanks

Kerry M

[R.G.]

The fact that the loop output impedance is lower than the MOSFET boost input impedance has no effect at all. It's hard to find anything that's not a lower impedance than the input of a MOS stage.

The 10Kinput impedance on the loop may be lowering the gain of the booster, though. Can't tell without a schematic.