A rough investigation on the Walter 2SK170 Le Passific RIAA preamp

Only the first stage was made up today on breadboard with 20 per cent at least variation in component values. Signal path:Dirty Dancing lp - Stanton 680 - 1st stage of Walter's le Passific - Realistic disco mixer at mic in (lower input load, a series resistor should had been used) - Sennheiser HD580. When Vb=9V, Vd is 200mV. When Vb is 18V, Vd is 2.5V. When Vb is 27V, Vd is 7 volts. It sounded clear, dynamic and nice but there was lack of depth (even in mono listening). For some reason best sound so far was with 9V with gate open and so charged that VD is 300mV. More investigation and second stage is needed.