I intend to purchase another 10 space API rack. Already have 11 API 500 series modules including two 512s and would like a few more 500 series pres. Main purpose would be for tracking...especially drums.
Which A-Designs EM pres might be best suited for sources such as kick and snare?
Do they have more, less or equal headroom then the 512s?

Any EM series A-Design owners care to chime here?

i do not have a 512 to compare but i have use the EM-BLUE on snare and the first time i heard it i was blown away!
i used a EM-BLUE and a EV-RE16 on a Ludwig acrolite.
i have been using the OSA MP-1-L3 on kick and it sound great.
but i do want to pick up a EM-GOLD or a EM-SILVER just not sure which:(
wish i could afford them both.
check out the A-Designs site for what they recommend each of the pres for.

http://www.adesignsaudio.com/p-1_emseries.htm

wish i could be more help i just do not want to say anything based on a old memory in regards to the 512.

hope this helps some.