Just got back from a monthly open jam session at a nearby venue. They have a Roland Jazz Chorus 90 for guitarists. I was the only guitarist at this month's session, and I stayed on stage playing thru it for about three hours. I was using my old Gibson archtop with a single floating pickup direct and we played mostly jazz standards. I plugged into the Low input and engaged distortion, but at zero, on the advice of another forum member who suggested that when I mentioned that the JCs can sound a little glassy. It helped give me a warmer sound, with a tiny bit of bite if I dig in. The volume was at about 9:00, the mid and two trebles near noon, and bass all the way down. No reverb, nor chorus.
This is a low intensity jam, with a pianist, a couple of bassists (one upright, one electric) a drummer and two vocalists, there was also a half dozen or so people watching. The amp could go way louder if I used the High input and turned up the volume, but that was not needed for this venue. Another venue I play at has the JC 120, and that thing goes super loud, like ear splitting loud. I find I like the JC 90 better, not sure what the difference is, but to my ears it sounds very nice for traditional jazz. It could also be the venue. The venue for today's jam has good acoustics, and one could almost play acoustically with upright bass, piano and drums, and it's more or less a jazz cafe. The acoustics at the other venue with the JC 120, are less appealing, but it seems OK as it's a multi-genre live house.
At today's jam, I set the amp and didn't touch it the whole afternoon. We played a number of tunes. I called Blue Monk and If I Had You, both laid back, one a blues and the other an old swing tune. I also called another old swing tune, Makin' Whoopee. Others called All the Things You Are and Blue Bossa, while the vocalists called a number of tunes, including Caravan and Smile. The archtop and the JC 90 sounded very nice for all of these. As I arrived the piano trio played a couple of tunes. The piano isn't miked, the bass is lightly amped (not sure what amp it was), while the drummer is kind of subdued. The second bassist was using an electric, which oddly didn't have as much presence as the upright. It could've been from using a light touch. Vocalists went through the house PA system.
When I was a fan of Adrian Belew years ago, I toyed with the idea of getting a Roland JC, and here in Japan JC amps are everywhere, but I never got one. When not using the backline amps at these and the other venues I frequent, I have a Henriksen Blu Six, which has a punchy Polytone kind of a sound, and I'm perfectly happy with that. But if I was going to get a JC, it might be a JC 40 to keep things lighter. That still weighs 15KG compared to the Blu Six, a class D 120W amp that weighs in at 6KG. As I slowly age weight and portability are important. The JC 90 weighs over 20KG, and the JC 120 nearly 50KG. Even so, overall, I see no need to bring my amp to any of the jam session venues.