I though they were the same thing. A 2 channel amp has four ouput terminals, L+, L-, R+, R-. A non-bridgeable amp has the signal on the L+ and R+, varying the voltage while both - terminals share a common ground, usually the same ground as the amp itself (0V). With a bridgeable amp, the L+ will contain signal while and the R- will contain an inverted right channel signal. To use an amp like this in bridged mode, you connect the L+ and R- only to a single speaker. If you fed the amp a mono signal (with a Y connection or whatever), you would end up with a the single channel's signal on L+ and an inverted (180 degree out of phase) on R-. I thought this was what BTL was.Originally Posted by R32 JUhl
The problem I can see is that the head unit doesn't vary voltage around a 0V reverence, it varies it around 6V reference. Also, based on that thread for vwvortex, the amp expects all the inputs to be BTL around 6V. It just happens to look for 6V on one of them for a turn-on signal.
Searching I found several circuit type parts that do BTL (I think around 6V), but nothing in a nice neat package. Am I being nuts. Does your solution or the one posted here accomplish the same thing. What are the output specs of the headphone or line out jack of the average PC soundcard?