Is a SUT needed?

Dear Raul, I submit that it's impossible to know for sure that your phono is within .012 db of perfect RIAA, because there's no way to measure that accurately. I'm sure it's as perfect as you can make it, however.

Good points.  I would only take issue with the implication that using ICs between an outboard SUT and a suitable MM stage is no different, in terms only of the potential effect of the connecting wires, than having a built-in SUT or a voltage gain stage before the MM circuit.  The external SUT not only requires much longer wires, making it susceptible to RFI and/or the effects of wire capacitance, but it also requires connectors, usually RCA type, at both ends of the ICs. Connectors are a major source of coloration, in my opinion, where low level phono signals are concerned.  This is a point in favor of built-in SUTs, if one must use a SUT.