09-10-2021, 07:09 PM
That is my guess right now as I figured the original control was a hum control like my 116X has. I'll be getting a peek under the chassis shied next week if all goes as planned. I do think it neat that they put Philco knobs on the two controls, even if they are earlier ones. Some other good news is all tubes check good except the 6L7 and 6H6, so the expensive tubes are all good.
No matter where you go, there you are.