I installed the Sparkos Dual Discrete Op Amp SS3602 for the RCA outputs on my Fosi ZD3. It seems to have calmed down the highs a little and the music is sounding a bit warmer than the original op amp that was installed. I didn't notice much change in the sound stage although I did move my speakers further apart again. Now the sound stage is sounding more of the way I expect it should.
I also turned off the Wiim Ultra equalizer. When I tried the Outlaw receiver and Wiim dacs, the music sounded really muffled and not lively, so I always felt like the equalizer was needed. I only listened for about 90 minutes so far and I feel like I can leave the equalizer out of the equation. I have almost always used an equalizer in my stereo setups so I have to condition myself to accept it the way it sounds without it. When I play CDs, the Wiim is out of the circuit, so no active equalizer is in play for that media. I think it sounds great without adding an equalizer while playing CDs. This leads me to believe the dac in my cd player is of good quality. I'm concerned that I am calling the sound warmer only because the EQ is off.
