RIAA Equalization
„Conventional“ voltage driven passive RIAA network. The network is driven by a linear amplifying voltage source such as an OPamp. Due to the inverted RIAA on the record the voltage source has to be capable to handle the full voltage swing of the boosted high frequencies with possibly insufficient headroom or even clipping in high amplifying stages.
Current controlled passive RIAA network. The network is driven by a current source such as a cascoding transistor. The signal current is injected into the RIAA network which resembles a frequency dependent load. Voltage drop across the load decreases with increasing frequency according to the RIAA curve.