preamp configuration

[audiofan]

Is there any hope with this configuration ?
The use of the OP AMP has 3 goals

- reduce load on VAS
- reduce distortion of output stage
- reduce thermal drift

 

[audiofan]

sorry......... here is the circuit...

 

[audiofan]

I had some spare time an I made a test .
Circuit works fine for first evaluation on a 20KHz square wave had no overshoot and a rise time of 1.8uS.
complete circuit below....

 

[Leolabs]

DC output offset/drift???

 

[audiofan]

Ofset is corrected with potentiometer, no test have been done yet for drift or distortion.