ACK dac or Muse 2 / older dac to replace Sa8260

Please advise Ack! users. I've been very interested in Ack! dac for quite some time and wondered if my system would benefit. The highs at times are too much, probably because of the revealing nature of Magnepans, and I'd rather hear a lusher, non- fatiguing, blacker background, fuller lows, and smoother well rounded mids. Would I accomplish this with a Ack! dac used with a Cary 303/100cdp or would I benefit more by using a different cdp, such as a Audio Aero Prima cdp or similar cdp?

I would not say that the dAck! has soft highs, but sweet and extened. The mid is not half so rounded as the tube DAC by Scott Nixon or the cj DACs--the dAck! having a more transistory mid. The bass is deep and impacting, but not midbass bumped like a tube DAC, a la Scott Nixon. The Cary is tube DAC, is it not?

The Cary 303/100 is a ss cdp and not a tube dac.