Before my Mono 15w went dead (replacement on the way) I swapped the stock speaker for a Jensen C12N8 and without being a trained ear ... it sounded better, especially after breaking in a little bit. Certainly warmer/fuller yet no loss of the sparkle/spank from single coils. Not sure if I'll even power the replacement up, before putting the Jensen back in it. I did the speaker swap iindependent of a JJ EL844s and a 12AY7 in v1, which I did a little bit later. Playing mostly at "1W", I was interested at getting the breakup at even lower volumes if I wanted it ... the EL844s seemed to do the trick, but I put the stock 12AX7 back in.