My RIAA Pre-Amp With JLH Component Values
You mean the op-amp version, they sound about the same really only the op-amp has less noise on it, as in the background hiss of the high gain needed.
If they're sounding about the same, that is encouraging.
Still, you might want to Spice Model the op-amp version to verify the part values, or spend some time with a spectrum analyser.
Here is a spice model you can use...
It generates the frequency curve found on the record itself. If you feed this in, the output should be a flat frequency response... In an AC analysis, the average levels for MM are 4mv and for MC it is 0.4mv.
The LAPACE calculation is inserted into the E voltage controlled voltage source's setup panel.
These are the actual curves set out by the RIAA
Hope this helps....