http://www.3daudioinc.com/
The 3DAudioinc.com microphone and preamp comparison CDs are useful tools if your CD playback system is sufficiently revealing. The producer of those CDs (Mr. Lynn Fuston) is up-front about the limitations of any such comparison recording. Nevertheless, even at the delivered price of $110, the 3 CD set is a great bargain if it points you towards (or away from) even one high-end mic or preamp purchase.
The differences among microphones are such that one might hear meaningful differences on any stereo (but don't be too surprised if you think the SM 57 sounds better than some mics costing 10 times as much). However, the differences among preamps are MUCH more subtle, and on some stereo systems, one might not hear any differences at all.
In my blind listening evaluations on an almost painfully revealing full-range playback system, all of the preamps sounded very good, and a dozen of them were outstanding. However, to my ears, there were three preamps that were more engaging, more musical, and seemed to "get out of the way" more successfully than the other 31.
Remember, I was doing a blind listening test, so I had no idea which three I had picked until I was finished listening. While your experience and listening preferences may be different, these were my three favorites.
1.) Earthworks Lab 102 (absolutely neutral -- tremendous drive and immediacy, caused uncontrollable toe tapping and head-bobbing, even after listening to the same assortment of half-minute musical phrases 30 times);
2.) Grace Design 201 (made the rather irritating male vocal takes sound listenable -- still more neutral and engaging than all but the Earthworks, but leaning very slightly toward a compelling sweetness); and,
3.) Neve 1081 (it didn't have the neutrality or sheer clarity of the other two, but it matched the drive and immediacy of the Earthworks and Grace Design in a way that was highly musical).
Again, there were probably 10 others that I would be THRILLED to have, but I thought the ones that stood out at the very edge of resolution, drive, clarity and musicality were worth mentioning.
Here's the list of preamps gathered for the listening test:
Amek 9098 Dual Mic Amp
Aphex 1100-Tube
API 512
ART Tube Channel
Audio Upgrades High-Speed Mic Preamp
Avalon VT-737
Buzz MA-2
Cranesong Flamingo
Daking 52270
dbx 386
dbx 786
D.W. Fearn VT-2
Earthworks LAB 102
Focusrite Red 1
Focusrite ISA 110
Focusrite 430-Producer Pack
GML 8300
Grace Design 201
Great River MP-2MH
Hardy M-1
Langevin
Mackie 1604 VLZ Pro
Manley Dual Mono
Martech MSS-10
Millennia HV-3B
Millennia M-2B-tube
Neve 1081
Oram MWS
Presonus MP20
Sytek
Telefunken V-76
Vac Rac
Vintech
Another wonderful resource is the "Project Sessions" disc, which is available through Alan Hyatt to forum participants without charge. I gave my detailed impressions of that disc elsewhere (about preamps I had never heard of), and only after posting my results did Alan tell me how much the ones I liked cost. Let's just say my ears apparently prefer very expensive electronics -- darn! If you're interested, do a search on "Mark H." and look for Comments on the "Project Sessions" CD. Email Alan with your mailing address if you'd like PMI Audio to mail you a copy of the CD.
Best wishes,
Mark H.
P. S. I'm *not* "anyone else who knows"; I'm a newbie groping my way through the dark, trying to learn as much as I can, and I'm grateful for the help I get from more experienced forum participants. When I re-read the title of this thread, I suddenly felt my participation was presumptuous and wanted to add this disclaimer. MH