I have gone back to gigging my '62 RI J through an S9 into either a Schro BMF1212 or Berg NV610, depending on the gig. Agreed that passive J's are a bit low output; though that depends on pup height to some extent. When I was using an S6, I did have to use a small tube pre to get the input gain structure where I wanted it. I find the S9 to be whole different ball game. With the '62 RI, I am setting the input gain and pre-out around 1 o'clock and output at around 9 o'clock to 10 o'clock. Any more and I catch it from the sound guy or just blow everyone else off the stage.
Bit OT, but, honestly some of these "power" discussions with these more recent amps just seem academic to me. I mean, I can't even get close to using the S9 all the way up to what it can deliver at any gig I'm playing; and I'm predominantly playing rock level stuff. Who cares what the wattage is? The darn thing is way past what is needed. Wish I could just put those type of posts on ignore at this point. Is the DB750 more powerful? Who really cares? I would certainly never want to experience the difference. God willing, I'd like to have some hearing left 10 years down the road. From a musical point you pretty quickly get to where that is just some kind of excess. I mean if it makes a cat feel better about having 10x more than they will ever use, then go for it. I don't personally think that's much of a practical point with these amps any more. Being properly set in the mix doesn't care what's not being used above that. Just my <2c. GL2A.