The Boogie's "Slave out" is a line level send directly from the speaker jack (not to be confused with a buffered recording out!) designed to work with the input of a dedicated power amp (that is buffered, though usually the manufacturer doesn't say it is - it is). Lets say instead of using the effects return (which would give you preamp only tone) to run an outboard power amp, you use the slave - you are using the full tone of your amp (power section/output tranny, etc). The downside is since it's line level coming off the speaker jack, it has to receive a buffered load otherwise it will sound like crap by itself, it's not like using the effects return to power another amp. One awesome use for it is to grab up something like the Palmer PDI-09 or PDI-03 (speaker simulators) and slave it from the Palmer to either a recording console or a house PA and -boom- no more microphones. When you start thinking about the Slave out, the possibilities start opening up.
