Extension Speaker for Silverface Princeton

[Rev. G Willie]

So, I've got this '80 silverface Princeton Reverb. And I've got this original Chicago Jensen 12" speaker. I'd like to put the Jensen in an external cabinet and run it along with my internal 10" stock speaker. My question, is it ok to run an additional 8 Ohm speaker cabinet using the Ext. speaker jack on back of the Princeton? It says 8 Ohms Total. Can I run the internal 8 Ohm speaker and an 8 Ohm external speaker without frying the output tranny?
Thanks

[Chuck H]

Does it actually say "8 ohms total" or does it say "8 ohms"?

All through the blackface era Fender amps had an extention speaker jack that was expected to run a second cabinet at the amps rated impedance. That is to say, if the amp had an 8 ohm output, they expected you to run an 8 ohm extention cabinet. This did present a less than ideal load to the output tubes. But I guess Fender didn't feel this was a safety issue. The silver amps mostly used the same or very similar transformers as their blackface counterparts. So I think you'll be fine just plugging another 8 ohms into the extention jack. FWIW that jack is in parallel with the mains jack so another 8 ohm speaker would be parallel to the cabinet speaker creating a 4 ohm load. If you intend to use only the external speaker for an 8 ohm total load, so you unplug the combo speaker, you will need to plug the external speaker into the main speaker jack because it is a shorting jack. the main jack must be in use for either jack to work properly.

Chuck