I've owned this pedal since '95. It's the second version with the mini switch on the bottom so you can footswitch from Clean mode to Blues mode, rather than from one of those to Solo mode.
I've been messing around with it the last 2 months after mostly retiring/replacing it about 10 years ago (after using it in a non-Dead cover band). It's always been highly versatile in its range of tones: sparking clean, fat vintage, pushed R&B, sweet blues, stinging blues, juicy hi gain, etc. (the manual has good tips for these). The Clean mode can give beautiful American-style cleans, with plenty of sparkle, and you can increase the Gain to where it gives nice breakup—but this varies quite a bit with the guitar and pickups.
You can get reasonably close to Jerry tone with it. The tone controls are highly interactive. I had stopped using it because I found it to be too dark and it almost always compresses—to me, those are opposite of the classic Jerry tone traits. I dial the Bass all the way out, or add a wee bit. I'm better now at dialing tones; e.g., I'm now better able to adjust Presence for openness over compressed.
The Blues mode is pretty useful, but I don't think it's quite Jerry tone. Switching from Clean to Blues, I have an issue matching the volume and having the gain that I want in each mode. If I set the Gain for that breakup in Clean mode, its presents as fairly high gain in Blues mode—at least, more than I want. There's another pot on the bottom to adjust that mode switching balance. If I balance the volumes, it decreases the gain in Clean mode, which makes it harder to get that breakup. I've experimented with using a lower gain 12AT7 in the Blues mode. It's still a balancing act, and I must adjust for the output of every guitar's pickups (I'm using G&L Skyhawks, Comanches, various ASATs, a Yamaha semihollow with humbuckers...).
I will say that running a clean boost (e.g., a Tim) before the Clean mode sounds absolutely glorious to give that breakup. (I haven't tried using Solo mode at almost no gain to see it that works at all, but the Solo mode has cascading gain stages and a truckload of compression....)
And, I was watching Richard Thompson and band on Austin City Limits circa 2000 and RT used one for his solo drive. So, it's nothing to sneeze at. But I'm sure he's not using it today.
It has outputs on the back that allow you to run it direct into a PA for an amp-free setup, or direct into a board for recording. There's a rackmount version that contains two discrete units with more voicing switches (it IS a Mesa), and you can even blend the units.
I'm running it before a 50-watt 6L6 Electroplex Rocket (incredible amp), and I think headroom helps. I struggled more with it into an 18-watt 7591A Ampeg Reverberocket 2.
I feel that it's a versatile tone tool, good for a wide range of styles, but it's a big and heavy piece of kit, and today we have so many smaller, better-sounding options for getting Jerry tone without all the futzing.
Last edited by nopunin10dead on Sun Jan 31, 2021 12:55 pm, edited 1 time in total.