I'm thinking of ordering an API 512c preamp and can't figure out for the life of me whether I have to get one of those overly expensive rack power supplies or whether that's just icing on the cake for those who need it. Please enlighten me folks.
Yes, you need the "lunchbox" for that and other similar modules, as the 512c needs a power supply.. That means that they are a much more attractive value if you buy a few modules, rather than just one, as adding each additional module lowers the price per unit.
There are API products, like the 3124, that are horizontal rack mount units with a built in power supply. But the 3124, for instance, is a four channel unit - and is proportionately more expensive.
