D Peter Maus ) writes:
Michael Black wrote:

I wonder how you used it as a preamp, given that the design doesn't really
make for using it for anything but a TRF receiver. Only three pins, so
the output comes after the detector stage.


There is an AF gain stage before output on the chip. So only a line
level AF amp is necessary to drive the loudspeaker. It drives a high
impedance headset quite nicely. When I first put it together I used a
pair of Brush Clevites. Later I used my first pair or HD414's which were
also 2k

Sorry, I now see I misread the part about a preamp. On first reading,
"produced a very nice tuner/preamp for a TRF receiver" came to me
as you used it ahead of a TRF receiver.

Michael