I have tried more than a few, and preferred the Tom Evans Vibe and Pulse, CAT Ultimate MkII, VTL 5.5, and my current Lamm LL2. I will qualify by saying I used the Calypso with a McCormack DNA500, which is not an ideal amp for the Calypso due to its lowish 10K ohm input impedance which would likely cause a roll-off of the lower bass response because of Calypso's higher output impedance in the low frequencies.