preamp for acoustic bass and classic guitar ???

[ebaba07baba]

My acoustic bass and classic guitar have fishman classic 4T preamp. But the sound quality isnt enough for me. so ı need advice about the below preamp (These are the only preamps for acoustic guitars that I can find in turkey )

1.Radial Engineering PZ-Pre
2.Samsamp acoustic dı
3.BBE acousticmax

Thanks for your answers.......