Yes it's really made for a car/boat stereo application, but it works for home stereo as well. I wanted something that was simple to hook up and didn't need it's own power supply. There are several brands on the market starting around 6 dollars US. Mostly from China (Like most everything else) Some have a transformer in the circuit and some are just a voltage divider made of two resistors per side. Either one works fine, Some are also adjustable left and right sides for the amount of drive that the downstream amp sees.
So they are called various names, but generally called a speaker level to line level converter. (which is technically wrong) but who cares?
This is because "line out" is a fixed amount of drive. It is either ON or OFF, but when on it stays pretty much at the same power level, whereas these devices have an output that follows the input as a percentage of the input - so the output varies with the input at say 5-10% of whatever is on the speaker terminals.
Both models I have use some fine gauge stranded wire for the speaker terminals and you will have to beef up the wire size to accomodate your connections to your existing bananna jacks. A little soldering and some male bananna jacks are what I did. It's just four wires on the speaker level end.
The output end has two RCA female jacks that connect to your downstream power amp. You will have to make up the cables for that as well, so it just depends on what you are hooking up to. But again, it's just two shield grounds and two center wires in RCA cables in most cases that are easy to find and fabricate if you can solder wires together.
BOSS B65N Speaker Level to Line Level Output Converter (parts-express.com)
The nice thing is that in some cases it saves you from having to buy an amp with it's own pre-outs. You can hook one of these up to ANY stereo that feeds speakers and make it work fine.
The only downside is that you will have to make up your own connections and adjust your drive levels with a flat blade screwdriver one time. After that, you control both amp outputs with the remote on your first "source" amp and the power amp is slaved to that.
