[Ron Ramirez]

As Tom pointed out, Philco switched to an 8 inch speaker in the second or late version of the 1936 model 116B, when they also redesigned the cabinet into a plainer rectangular box that is slightly shorter than its predecessor. I am sure it was done to reduce costs. The average Joe would think the 8 inch speaker sounds as good as the 10-1/2 inch speaker.

And so the 8 inch speaker was retained in the 1937 successor to the 116B, the 37-670. But I don't understand why Philco reduced the IF amplifier stages from two to one, and added all of those 6J5Gs. I think they wanted to retain a large 11 tube tabletop in the lineup, but it was no doubt cheaper to make a set with one IF amplifier stage than two.

You can see the beginning of the end of Philco's quality in the 1937 models, and the slide toward cost-cutting and cheaper products overall.

Anyway...

Gene, I see your 37-670 has a conventional 1937 power transformer. Some 37-670, 37-2670 and 38-2670 models have a larger power transformer with the rectifier tube offset (not in the center), and a 110/220 voltage switch on top of the transformer, next to the rectifier socket. My 37-670 has the odd transformer with the voltage change switch.