Mixer recommendation

That’s a great size.Nice and compact. Way over my budget though.

Does anyone have experience of the Alto Mixers? Like the ZMX122FX

I like this. It's small. But would it be enough for 4 Volcas, some POs chained to one line in, some sort of lead synth (a Roland Boutique (or maybe 2) and an effects box?
Also, it's passive so i won't be able to plug in some headphones right? no amp?

Well, if you plug in a signal hot enough, you can use one of outputs for headphones too. ATM I’m using it for mixing a couple of noise-makers (Kastle & Olegtron 4060) into my headphones at the office. For effects, it’s tricky, since the mix output doesn’t have a separate volume control. So you can’t do send amount. Unless you put two of them in a row or something.

Does anyone have experience of the Alto Mixers? Like the ZMX122FX

I have that mixer. It’s perfectly fine, nothing special. Internal FX presets are really limited though, and many sound the same to my ears.