This is mainly for tomp, but I figure we could all benefit from the answer...
So, I was looking at the AD datasheets for the the OP27 & OP37. They're pin-to-pin compatible, so they could easily be substituted for each other in many circuits. tomp said/implied at the meeting last month at my place that the OP27 was a better choice for an MM RIAA stage, while he preferred to OP37 for an MM step-up. The OP37 datasheet recommends the OP37 over the OP27 for gains >10, with either being a good choice for gains between 5 and 10, OP37 not recommended for gains <5.
So, assuming a two-stage MM RIAA pre-amp, (is that correct for your design Tom?) I would assume the gain of each stage is >10, so why the preference for the OP27 in this application?
Roscoe