JP11801 - Brownsfan is correct - your DNA-1 Rev A Balanced has an input impedance of 10KOhm. This limits your passive choices somewhat - transformer-based designs (TVC) units are your best bet, and resistor-based designs (with conventional volume pots or stepped-attenuators) will not match well. TVC passive designs have made quite a few audiophiles happy and are worth looking into. It takes an extraordinary active preamp design to deliver the kind of transparency you are getting from your direct connection, but you may also find it difficult to get the same level of dynamic impact from a passive design.
Best regards,
Steve McCormack
SMc Audio
Best regards,
Steve McCormack
SMc Audio