One Bad Tube

I have a pair of Triode Audio TRX-M845 Mono Blocks.  Just set them up this morning after waiting a few months for everything to arrive.  Output tube 845*2, Driver 845*1 , Balance in 12AU7*1 , Pre 6SN7*1.  One of the tubes (Driver labled V3) is not working. No sound coming to the right speaker.  To verify it is the tube and not the socket, I swapped the Driver with the Output tube labled V2.  The same tube refused to light up, but a suddenly I had sound.  All 3 of the 845 tubes appear to be identical.  So my question is this.  Can the amp run fine with only one of the ouput tubes working?  I assume there is a reductioin in power/signal, and more important, do I risk any damage to the amp using it with one output tube not working?  It will be some time to get the replacement tube and I would like to have musi in the meantime.  Appricitate the assistance.