I have an old Korg Pandora. Small, drives a proper pair of headphones. I run it from 4xAAA rechargeable batteries and they last a while. It has an ok integrated tuner, FX, and has a tap reverb, which is a lovely thing.
Otherwise, I use a cheap 12 track mixing desk. Has phantom power and XLRs for some pedals, and it's better with a Chapman stick than the Pandora.