Lean sound. What's the cause?

Thanks for all the comments. What I mean by the "lean" sound is in the comparative sense, not in the absolute sense. Unidisk SC has a built in volume control, so I can bypass the preamp and compare the results. I thought it sounded leaner with the preamp in the chain than without. MAP-1 sounds pretty neutral otherwise, and it doesn't add or take away much in the sound.

Thanks for the response John. I do have a slight suspicion on the performance of MAP-1, but I'm going to give it benefit of doubt due to the lack of evidence. However I am looking at two channel tube preamps in case I need to replace McCormack. The preamps I'm considering are BAT, VTL, and Conrad Johnson. Do you have experience with any of them? Particularly I'm interested in VTL TL-5.5, C-J Premier 17LS2, C-J CT6, and BAT VK-31SE. I understand that there are two different ways HT bypass is done. I need a preamp capable of providing unity gain of selected source on the shared output, not the ones that provide separate set of HT bypass outputs. Comments appreciated.

Larry,

I agree with your assessment. I like the simplicity in the setup with Unidisk SC driving the amps directly, and it served me well.

The reason I've added a preamp is because I have recently added Accustic Arts DAC to the system. For red book I use the DAC with Unidisk used as a transport. The red book sound has improved. But it came with the added complexity in the setup as I need to switch between Unidisk and DAC for playing SACD or red book. So I gained some and lost some. The red book has improved at the expense of slight loss of bass in SACD.