And you're a lap steel player, you say? I'd like to hear more about that, too. I love lap steel, and would like to hear what kind of stuff you play, what tunings you like, etc.

(I've got an old off-brand steel called a Roy Bert that I keep in Dobro G.)

I've never tried a guitar speaker in a automotive speaker enclosure, but I have played through a little Yamaha 1 x 10" wedge monitor once or twice with my old rack preamp/power amp setup I had for awhile. I liked the size and "angleability" of that shape, but the tone from the 10" PA speaker and little horn was pretty full-range and fizzy, as you might expect. For dedicated guitar use, I think it might have been pretty cool with a guitar-specific 10 in there and with the horn removed, leaving a reflex port instead. I'd have tried that but it belonged to a bandmate who was not receptive to ideas like that.

I don't have any experience with the Mosvalve power amps, but I did use a Tubeworks Real Tube preamp into a ADA Microtube 100 power amp for awhile. This was a 50 watt/50 watt stereo 1-rackspace thing with a pair of 12AX7s in it, so not a real tube power amp.

We had a caveman drummer and a bass player who pushed his Hartke 350-watt bass stack pretty loud. I was able to keep up with this power amp, using one side to drive a 2 x 10 cab and the other to drive a 4 x 12. You might keep an eye out for used ADA stuff. It's light and compact.

I forgot to mention in my previous post that one of the surprising slaving experiments I tried involved running the little Peavey's line out into the FX return of an older Laney AOR 50 tube head, driving some 4 x 12 cabinet.

The AOR 50 was a pain to dial in, with all its various cutting/boosting functions you accessed by pulling out knobs. "Replacing" its overpopulated tube preamp temporarily with the simple 5-knob SS Peavey circuit sounded better to me. And hearing my Peavey tone through a 2 x EL34 power stage and 4 x 12 cabinet was pretty cool, too.

Well, the guy who owned the Laney half-stack didn't think it was as cool as I did, but what the hell.

Hi, I'm new here too. I do something like what you're asking about all the time, using a Peavey Audition 20 in the way you'd be using the Line 6: as sort of a tone supplier to another amp.

My Peavey's line out jack sends a signal that can safely drive another amp's instrument input, if the Peavey's volume is kept fairly low. Chances are yours is similar; just set the receiving (or slave) amp to a clean, neutral-sounding tone so as to color the Line 6 tone as little as possible. Experiment with gain/volume settings on the Rogue, always trying for a clean, neutral sound and while keeping an ear out for "input overload" distortion, which might happen if the Line 6 signal is pretty hot and the Rogue's input gain is turned up too much to hande it.

If the slave/receiving amp, the Rogue in your case, has a "line in," "power amp in" or "effects return" jack, use that, because it will bypass the Rogue's tone controls and send the Line 6's "line out" signal straight to the Rogue's power amp section, making it act as a powered speaker, and all tone/volume control would come from the Line 6 that way.

The process of slaving a tone you like through something else can sometimes give surprising results, both good and bad. In my case, I still hear and like the basic gritty-clean character of my amp through other amps, but something about the combination of my amp's own internal power stage/small open-back cabinet/tired old 8" speaker definitely adds to the sound I like, and is absent when I slave it into something else.

Post again with your results after you've tried it!