Sytek MPX-4Aii by gehauser
I have had the Sytek MPX-4Aii since late 2007. My version has 4 stock channels (no Burr-Brown). I got it with 4 like channels so I could shoot out 4 mics at once. It is a solidly built 4-channel pre with individual mute, phase, and phantom power buttons and clip indicator for each channel. The gain knob for each channel has numerous notches, so it is easy to reproduce a previous setting. The Sytek has superb specs across the board. I can compare its sound to the other pres I have worked with (m101, Solo 610, Pacifica, 4-710d). In A/B tests using these pres, the Sytek would be my preference for acoustic instruments (guitar, mandolin, old-time banjo, fiddle, hand percussion).
I have found the Sytek to be very dependable, with lots of clean gain and a very low noise floor (transformerless input). I prefer it over the Grace m101 for acoustic instruments because it has more punch and is quieter when pushed to high gain. The Grace captures a little more detail in the highs, if I use my imagination. The Sytek sound is best described as clean yet slightly colored, as it characteristically imparts a big, full low end and smooth (unhyped) upper mids and highs. Its mid-range is solid, but not as forward as that in a Pacifica. The Sytek captures fast transients to perfection, which makes it a good choice for recording bluegrass and old-time music where hi-tempo flatpicked leads are common. It sounds bigger than the Grace, but not quite as big as a Solo 610 or Pacifica (although it is close). It's upper mids and highs are slightly more rounded and not as bright as a Pacifica.
The Sytek has given me good results recording acoustic instruments, piano, vocals, choral ensembles, and percussion. It is an excellent value at under $250 per channel, and it is an especially great choice for recording quiet sources.