Eeyore wrote...

is left for the preamp to use, as the 3MHz TL072 bandwidth
is reduced to 300kHz. Sheesh!

I know what you're saying but it works out in practice rather
better than the numbers alone might suggest.

I should add I'm thinking of the upper end of the spectrum
where the loop gain is low, for example 5kHz where it'll be
300kHz/5kHz = 60. That can be further reduced as the opamp
drives various loads. I suppose you'll say low distortion
isn't so important at these frequencies. Did you measure
and plot it?


--
Thanks,
- Win