The 648 chassis is designed for operation on 100 to 125 volts, either AC or DC. The tubes used in this chassis are:

6A8G Oscillator-Modulator
6U7G I-F Amplifier
6Q7G Detector, AVC, A-F Amplifier
25A6G Output
25Z6G Rectifier
W-46773 Ballast Tube

The 648 Chassis was also used in the following three models:

C648B Ivory Finish (painted) Cabinet
C648C Red Finish (painted) Cabinet
C648D Wood Cabinet