Sorry gus, dont really understand your last msg?
I am only changing the source resistors R8 and r5 and using j201 in T3 and 2n5457 in T1.
I dont have any switches and only have cardioid.
Could you explain what you meant in a bit more detail please? cascode?
I dont know what im aiming for here voltage wise, the voltages ive found before were from a work inprogress post and havent been confirmed as correct?
I understand these transistors have to be biased correctly and the FETs need correct voltages to operate properly, my knowledge is pretty low on all fronts with these, so yeah im stabbing in the dark really until i get some firm voltages.
looking at T4, i seem to get 43-44v on collector and when i twiddle R5 or R8 i can get 20-32v sort of range on base and emitter.
ideally i need to know what T3 should look like voltage wise, is 2.69v on gate correct? along with 3.11v on source or are these voltages not really important and the emitter of T4 and drain of t3 important?
there is then exactly the same problem on the other two T2 and T1?
testing at c15/r15 i am getting 41v which does drop to a steady 39v.
I found c17, c18 and c12 where the wrong capacitance, had 220nf in rather than 22nf!!!
also c8 and c9 were 100nf rather than 10nf!!
transformer seems to check out fine, 60R on secondary and 130R on primary, good inductance on it as well.
capsule ive taken out of a working fet47 which sounded fine, so no issues there, but still the same low output on one version with j201 and 2n5457 in it, on another version its just got j201 in it and its much louder!!??
i just cant work out why there is such a volume difference?
both of them sound pretty trebly as its obviously not biased properly.
i will put a 1khz signal in and see where the gain changes, T4 emitter around the 22v mark seems to sound better.
