Like MarshallMark in this thread, I bougt this amp because it's a 5 watt, 1x12, two channel, single ended EL34 Marshall w/built in reverb, and less because it has Slash's name associated with it. Nothing against Slash, just not my goto rock subgenre, etc.
Since getting it a few weeks ago, I've been rolling various old tubes and speakers through it, trying to grab a tone that's a bit more open and, frankly, louder. This is where I'm at now:
V1: vintage Japanese-made IEC/Mullard 12AX7
V2: vintage US made RCA 7025
V3: vintage Japanese-made IEC/Mullard 12AU7 -- this tube drives the tone stack and changing to a lower powered tube seems to make the sound less harsh and brittle to my ears.
Power tube: JJ KT-88 (HUGE IMPROVEMENT, IMO)
Speaker: Scumback M75-PVC, open back cab; this is a great speaker for this amp, IMO, but I have a M55-PVC on the way so I hope to be giving that a try within a week or so. And I guess I'm just not into the closed back sound.
I am loving this setup! The KT-88 really gives the amp more headroom and imparts a lot of "body" to the notes. It also makes it louder, which doesn't hurt. I tried several different EL34s first, and while they definitely darkened the tone, they also gave more compression than I wanted. The KT-88 solves that issue. If you have access to one, I suggest giving it a try and seeing what it does for you. You may be surprised.
The clean channel is really great, and I think I like it as much as the OD channel, if not more.
I will try to get some clips together, maybe this weekend, and certainly after the M55 comes.
Glad I found this forum. Looking forward to hearing how others are using their SL5s.