Stomp boxes that enhance a traditional jazz sound?

[Boston Joe]

A fellow showed up at a big band rehearsal with a Flyrig and a cheap powered PA speaker. Sounded good. Flyrig?

I'd never heard of one before I read this. Sounds good, though, and the price is right.

[El Fundo]

I bought an Xotic RC Booster v2 the other day and I’m thinking I will always use it. Very clean and transparent. Really thickens the tone, which is especially useful at low volumes. Has treble, bass, and mid controls which are very responsive and work great for sculpting your sound. It’s shocking how thin my sound is when I turn it off after using it for a while. My new, longed-for secret weapon!

[Jehu]

I have to put in a plug for the Wampler Tumnus Deluxe. Awesome boost/transparent overdrive for fattening things up and adding a bit of spank. The Deluxe version includes treble, bass, and mid for shaping and taking out that Klon mid boost, if you so desire.