I've got a machinedrum some old monosynths and hopefully soon a DSI tempest that ill want a live on stage sub mixer for. So I'm looking for a small mixer that has decent quality built in delay and reverb FX to put some of the tempests channels through. Ideally 12 channels or more with 2 busses of FX.
all the analog desks with built in efx are pretty low level and awful . there designed to wack a bit of reverb on the local wine bar accoustic duo
I dont know what your budget is but the yamaha digital desk have good efx , some actually really good efx . You can pick up an 01v96 for about $1200+ or if you cant go that far an 03d will be about half that .
aside from that why not a couple of budget but good efx processors?
A few stereo channels for L+R synths/dmachines
A few mono channels
Built in FX
USB for backing tracks, or software routing of FX from the AUX
A few AUX sends for external FX if you need it.
Above budget range EQ, very useful EQ!