One of the projects I have going right now is a contemporary acoustic trio and the BL just sprung a PA on me at rehearsal tonight. It's a Yammy EMX640 powered mixer with a couple passive mains and a powered monitor. I have a TCE BG250 112 combo, which has been doing just fine in the loudness department. We were doing a dress rehearsal type setup tonight and he asked me to plug in so they could hear me in the monitors. This should not have been a problem; there's a balanced out from my amp. But, when the DI out was set to "pre" the PA sounded like liquid crap and when the DI out was set to "post" it sounded like solid crap. When the amp sounded good, the PA was all farts except when there was no low end at all. When the PA sounded good, the amp was shrill and harsh with crunch and hum taking the place of actual bass notes. I had maybe 10 minutes to twist knobs and couldn't find ANYTHING. No matter which switch I flipped, no matter what knob was where to which part of the whatsis - YUCK. I've never been in this particular situation before where it was just not possible for me to get an eq that didn't sound like an unsound kind of sound, if you know what I mean There are factors: I'm a hired gun, so no room to complain. I'm also really, really broke, so no new gear. The gig is a 3 hour cover set at little wine bar in an affluent part of town, maybe 100 people total, half seated, no giant volume levels required. My amp would cover this no sweat, but the man pays, so he gets what he wants. The instrument is a DB, piezo pickup with a 1M output impedance, no preamp. I use synthetic strings for extra old-timey thump and no mwah in sight. Thus, plugging directly into an instrument jack on a PA is out. I have sent DI out from the amp a bunch of times before and never had a problem, although SE were running the board. And the board didn't suck. There's some gear in the cabinet that might be useful. There's a SM57 for micing, and a little powered monitor with a 3 channel mixer, and a laptop. I also have a Zoom B1on which I have formerly used as a filter to HPF, remove a measure of crappyness, and buffer pre-DI to get the impedance right, before I got this amp. It does not do a good job. I really, really, REALLY prefer the tone that comes out of the amp (and that I think is supposed to come out of the DI set to post eq). TL;DR So, now the question: How do I get a good house tone out of my amp and still have something that isn't embarrassing on the not very adjustable mixer? Should I just dump all the lows from the PA and carry with the amp? Could it be crappy signal path or low strength or something? Maybe split the signal with clever routing and send the PA something run through the Zoom for preamping? Or just use the Zoom in front of everything to get a little shaping and gain but which is impossible to really test until sound check before the gig on Saturday? Is there a trick or magic frequency or anything?