[Ron Ramirez]

A shortcoming, I think, of the 37-670 is that it dropped a stage of IF amplification compared to the radio it replaced, the 1936 model 116B. It wastes a 6J5 as a dual diode detector/AVC diode (the grid is used as a second "plate"). Philco could have used a 6Q7 as a 1st audio tube and used the diode plates as second detector and AVC diode, freeing up that tube socket (and adding another IF transformer) so it, too, could have had two stages of IF amplification. But you can tell in 1937 models that Philco was beginning to cheapen their products, something that seemed to snowball after Jim Skinner left the company in 1939.

Of course, mine isn't working at present but I would probably compare it to something like the high-end 1940 Philco 40-195, 40-200 or 40-201, which have similar circuitry, especially the audio sections.

The 670 has a lot of tubes dedicated to the audio portion of the circuitry, mostly 6J5 triodes. The aforementioned 6J5 used as a dual diode detector/AVC, a 6J5 1st audio amp, a 6J5 phase inverter, two 6J5 drivers, two 6F6G outputs.

Thank you, Tom (TA) and Tom (Hamilton) for letting me know your 37-670 sets have the conventional (110 only) transformers. I used to own another 37-670B years ago, and I am 90% positive that it, too, used the conventional 110-only transformer.

Mike - I thought you might appreciate the photo of Nixy!