Mike transformer Ratios are 1:5 or 1:10 nothing else!!

the 1:8 I was talking about is not a Cinemag 75101. But, yeah I should have maybe stuck with the OPs components in the example.

With a 1:5 input, 1:2 output, and standar 40dB opamp gain, you have 60dB exactly, so maybe that's the way to go.

Re: load Resistor, you want it to give you 1K5 on the input side.

For a 1:10 you use 150K because 150K / 100 (impedance ratio = turns ratio squared) = 1K5 input impedance.

For 1:5, (ad 600 Ohm impedance) if you work backwards off the 600 Ohms input, then multiply by 25 (impedance ratio) , you get 15K as your load R. Maybe the others can chime in? So sounds like you found your problem?? let us know..

Anyway, with the Cinemag, connect pins 2 and 3 to put the windings in series.

I went through these same steps 2 weeks ago and it ended up being the diode, that's why I mentioned it. good luck.