Since you are asking such a broad ranged question you are likely to get responses all across the board unless you further define your requirements and preferences, such as balanced-XLR ins/outs, display, remote, tubed or SS, active vs. passive, maximum output impedance to go with your amps (or list the amps), etc. For example, several I have owned and found to better the Calypso (to my ears) included;
Lamm LL2 Deluxe,
CAT Ultimate MkII, and
Tom Evans Vibe with Pulse
Lamm LL2 Deluxe,
CAT Ultimate MkII, and
Tom Evans Vibe with Pulse