I read through M-J's cascode stuff today. gm1*R_load is close enough. If I can realize +10 mA/V, a 30k load resistor will get me a gain of ~250. Now we're talking...output z of 30k leaves a 300k RIAA to play with. that's possible.Look at a E180F with gm of 50 mA/V and we can get output z down by a quarter and still keep stage gain in the mid-200's. If it can be done quiet enough, we're almost in std output moving coil area with a follow-up E180F grounded cathode and CCS plate load.
I'll call this the 'hand waving' stage....
regards,
Douglas