Surely the most obvious answer is to look at your speakers or find the right source that complements your amp and speakers as-is.
It's going to be very hard to solve this if the root cause is really the tweeter levels in the Dynaudios. That's really a function of the crossover design (may need a change of resistor to attenuate the treble - not easy if DIY challenged), room acoustics and speaker placement.
I think many DACs sound quite different, so that would be the easier thing to change. I don't think it's a question of tubes being the only answer here, either. Take your pick depending on your price and then go audition.
Some suggestions: NAD M51, Audio Note 1.1, Metrum Hex, AMR DP777, Naim DAC, Resolution Audio Cantata
http://www.alldacinfo.com/?page_id=242
It's going to be very hard to solve this if the root cause is really the tweeter levels in the Dynaudios. That's really a function of the crossover design (may need a change of resistor to attenuate the treble - not easy if DIY challenged), room acoustics and speaker placement.
I think many DACs sound quite different, so that would be the easier thing to change. I don't think it's a question of tubes being the only answer here, either. Take your pick depending on your price and then go audition.
Some suggestions: NAD M51, Audio Note 1.1, Metrum Hex, AMR DP777, Naim DAC, Resolution Audio Cantata
http://www.alldacinfo.com/?page_id=242