J.C. - The valves in this Porta-bass are as follows: 3 x ECC83 Pre-amps & phase splitter, 1 x EZ81 Rectifier & 2 x 6BW6's for the output tubes. These were a Brimar product, on the B9A base (same as the EL84 with different pin outs) & in fact were identical in specifications as to the very famous octal based 6V6.
Note the use of a PCB.
The novel internal Pilot Light which, as well as indicating that the amp is powered-up, also provides a very impressive glow inside the amp casing.
Wow !!