I have been using the preamps on the board of my Mackie 808S powered mixer. In fact, I just finished recording for a CD of our band using M-S micing with AT4033 and 4050 mics. I must say, the results are quite good. I have not used a high quality stand-alone preamp, so I have no basis for comparison. Next time, I might use two 4050's in a Blumlein array, so we can just sit in a circle around the mics. But for small groups in a semicircle, M-S is a very cool way to go. It gives a more natural stereo effect IMHO. Al