I've been thinking about the gain structure of the OP6 to see if that throws any more light on the subject.
If we are given that the Gain max is 90dB and the output level is +18dBm then the input level to the amp is -72dBm, so far so good.
The input transformer is probably +20dB so the input to V1 is -52dB.
V1 would be expected to have a gain of +42dB, so the output into the Daven/switch is about -10dB.
Doug says the output transformer is -20dB so the voltage on the primary (ignoring losses) is +38dB.
V2 and V3 are in a feedback loop and so I estimate their combined gain to be about +48dB, this means that the input to V2 is about -10dB.
So it checks out working from either end of the amp, that the level is about -10dB with the unobtainium on no feedback/switched to output max.
Can some others check my reasoning here?
best
DaveP
If we are given that the Gain max is 90dB and the output level is +18dBm then the input level to the amp is -72dBm, so far so good.
The input transformer is probably +20dB so the input to V1 is -52dB.
V1 would be expected to have a gain of +42dB, so the output into the Daven/switch is about -10dB.
Doug says the output transformer is -20dB so the voltage on the primary (ignoring losses) is +38dB.
V2 and V3 are in a feedback loop and so I estimate their combined gain to be about +48dB, this means that the input to V2 is about -10dB.
So it checks out working from either end of the amp, that the level is about -10dB with the unobtainium on no feedback/switched to output max.
Can some others check my reasoning here?
best
DaveP
