On Tue, 2006-12-12 at 13:16 +1030, Tim wrote: > On Mon, 2006-12-11 at 14:18 -0700, Robin Laing wrote: > > Also look for external amplifier to see if changing that makes a > > difference. It was necessary to turn this on for my laptop. > > What does that switch actually do? I've been playing with sound on a > desktop box, and trying to work out why "headphones" acts as my master > volume, and the master volume has no effect. I've been trying out > different options, and the external amplifier one makes no differences > that I can detect. > > This, on a FC6 box, as a fresh installation. > > -- > > Don't send private replies to my address, the mailbox is ignored. > I read messages from the public lists. > Depends on the sound device. If you have one of the fancy 6 output surround sound types, it has separate outputs for each speaker channel, and a headphone jack. If you then get a typical set of PC speakers wired for the mini jack and plug them into it, then you get control of output at the speakers via the master, and at the headphones by the headphone control, which would then be driving the pc type speaker set (like I do). Some chips have totally isolated inputs and outputs internally, with digital control (I used to test the chips, so I am pretty sure of what I am saying). In these chips, the design of the application board can take the outputs of the separate channels and run them through special ports internally by programming or by hardware coding on the installation of the chip (tying some pins high or low). So one chip can do a variety of duties. And how you connect from the chip to the board edge is part of the board design, and then where you plug the cables in will affect some forms of performance (similar to the headphone jack vs speaker outputs I mentioned earlier.) The sound board is no longer just an amp and wave generator. It is a very complex sound system nearly as advanced as a theatrical sound system. Some theatrical systems are just built of bunches of these chips even. YMMV. Regards, Les H
