At present, I have a Parasound Halo P5. Very nice piece of equipment. Wit the OTL, I find that the low end with my Klipsch Forte's is so good, I turn off the sub all together. Once I get the Zu Druids, I will advise further but suspect I will need a little low end help. Love the Halo P5 and also Oppo 105 is a great unit. running that balanced to the P5 which removes the DAC on the P5, only using the Oppo DAC.