the local oscillator runs 455kHz above the RF. The center tapped audio detector transformer is replaced with a custom built IF transformer and filter. The audio output transformer of the direct conversion set is replaced with the 2nd IF transformer. The detector is now a 1N34A diode, and the detected audio is reflexed once again back through the tube with the audio finding it way to the final audio output transformer. Another difference, is that in order to collect the three separate signals (RF, IF and AF) to feed into grid 1, I'm using a tertiary winding on the RF coil T1. Also, there is a clear DC path from the detector diode all the way back to grid 1, which will provide AGC voltage.