The Farnell ones have a current gain bandwidth product of 200kHz. The Toshiba ones were 3 MHz. The slower ones would have significant cross conduction in class B at high frequencies due to hole storage. However they would likely be OK on music signals.
Genuine Toshiba
The Toshiba devices has clear red lettering on the can. On the underside the older Toshiba devices had an asymmetrical dumbbell/mushroom shape as part of the way the can was pressed. Two photo files of genuine devices are attached. The 2SD424 were even better and will do a good job of replacing the 2N3773s.
"Any advice on how to spot genuine Toshiba 2N3773 T03 transistors, I recently bought some on ebay and they didn’t have the lettering as in most pictures, the base seems thick enough though ?"
The Toshiba devices has clear red lettering on the can. On the underside the older Toshiba devices had an asymmetrical dumbbell/mushroom shape as part of the way the can was pressed. Two photo files of genuine devices are attached. The 2SD424 were even better and will do a good job of replacing the 2N3773s.
"Any advice on how to spot genuine Toshiba 2N3773 T03 transistors, I recently bought some on ebay and they didn’t have the lettering as in most pictures, the base seems thick enough though ?"
Good for centre channel for cinema 
I use a pair of 7 series modules which Brian had reworked, and they are superb, so an extra module would be good to have. Also the westrex box contains other goodies. My grandad worked for WE from before the war and continued working for the cinema's with westrex as his main supplier up until the 80's.
I use a pair of 7 series modules which Brian had reworked, and they are superb, so an extra module would be good to have. Also the westrex box contains other goodies. My grandad worked for WE from before the war and continued working for the cinema's with westrex as his main supplier up until the 80's.
I have created a website with most of the important Crimson Elektrik schematics and info. Let me know if anything is absent and I shall add it into the site.
See https://brianpowellaudio.co.uk/
See https://brianpowellaudio.co.uk/