Try it with the tube output stage. Also, you should check out the latest up sampling receiver from Cirrus Logic CS4396-7 DAC and their CS8414 Receiver. It just might fit that's my plan, the also have a component for upsampling.
The CS4396 is a complete, high-performance 24-bit 48/96/192 kHz, stereo, digital-to-analog conversion system. The device includes a digital interpolation filter followed by a oversampled multi-bit ÄÓ modulator which drives Dynamic-Element-Matching (DEM) selection logic. The output from the DEM block controls the input to a multi-element switched capacitor DAC/low-pass filter, with fully-differential outputs.
This multi-bit architecture features significantly lower out-of-band noise and jitter sensitivity than traditional 1-bit designs and the advanced DEM guarantees low noise and distortion at all signal levels.
Up to 192 kHz sample rates
120 dB dynamic range
-100 dB THD+N
Second-order Dynamic-Element-Matching (DEM)
Low clock jitter sensitivity
Digital de-emphasis for 32 kHz, 44.1 kHz, and 48 kHz
External reference input