This single low noise JFET input discrete RIAA stage utilizes a single 2SK170BL in a discrete high gain circuit with a 300MHz PNP driver loaded with a FET current source and 300MHz BJT Class A output. The input FET is sufficiently low noise at 1nV/rt Hz yet provides input impedance isolation of the feedback RIAA stage (an interaction common in non-differential BJT inputs) to eliminate HF gain errors.

The module is fitted standard with 47K//100pF cartridge loading and gain of 40dB. Other loadings and gains are possible by substitution. The equalisation follows the IEC extended bass (below 50Hz) characteristic to 20Hz with a 2 pole rolloff below to reduce 3 - 4 Hz warp intrusion. Also included is the ultrasonic response correction to compensate the HF response for cutter pole response errors, lack of which increases sibilance and edginess on instruments in many designs.

Input Sensitivity 5mV for 500mV out Input Impedance 47K ohms and 100pF Gain 40dB (1KHz) with other gains possible Subsonic Filter 14dB @ 3Hz Bandwidth IEC modified RIAA +/-0.25dB. Output Impedance 47 ohms Load Impedance minimum 10K Headroom 30dB at 1KHz Power Supply +/-15V DC low noise regulated for best Current Draw 15 - 20 mA. Dimensions 51W x 65D x 15H