Radial Tonebone PZ-Pre acoustic preamp. I’ve owned it for about 16 months and it has worked great with a passive violin piezo pickup, various acoustic guitars, and even an electric with a piezo pickup. The pz boost button did a great job matching impedance to what the violin needed—this was my main reason for purchasing it.
Everything works on it like it should. It comes with a Radial 15v power supply.
I am switching to a Radial PZ Deluxe for a smaller form factor and since I don’t really need the dual input of the PZ-Pre.