I totally reworked Series 2 EQ that I replaced ALL components on. 1% Vishay Metal Film Resistors 1W - 3W. All SoniCaps in the audio signal paths. Vishay made in USA low ESR 100uF Capacitors, KEMET super low ESR 475uF Capacitors in the 20VDC, 18VDC, & 16VDC power rails. A Toroidal Transformer feeds both the EQ box and the balanced/unblanced/balanced input/output adapter board with 8 OPA627AU OP-Amps heat sunk and mounted on Brown Dog adapter boards.