A Switched Loop Gain Option

[Mike_New]

Hi Karl,
I'm glad I asked you to join us,
Yea you have got about what I have except I could not
find a place for the sixth resistor shown on my block schematic. which appears to go from the junction of C210 and R208 to the output of the OP amp. at the point where C211 and R206 connect to the output. There are only 5 resistors shown in the circuit diagram, so I guess the block diagram is where things are wrong.

Your OP amp schematic clearly shows what is happening so now we only need to set up some RC conbinations.

The feedback resistor R207 could also have an affect on the response.
although all my information shows changes only to R209, R208 and C210.

In order to arrive at a set of possible and meaningful values over a range of responses, do you think it would be possible to take leads from the connect points on the resistors and OP amp to a tempory circuit board outside the SL1200. The possiblity of oscillation due to the wiring is what concerns me.