Now is the time to upgrade my current RIAA stage. A bit unorthodox approach for a valve enthusiastic but you will see me now with my hands on sand. A very simple JFET input stage with a shunt cascode pair to drive the passive RIAA network. The final gain stage is an OPA604 with remaining part of the RIAA network. The Op Amp is forced into class A by a nice pair of BC847C forming a CCS.
Given the shunt cascode bipolar is an PNP Darlington formed by 2 BC860C low noise and the CCS has also SMD devices, I started by soldering these into 4 PCB adapters for SOT-23 devices
More to follow…(just a start)