Can I use Mosfets to disconnect a 3-Watt speaker from an amplifier circuit without any loss of sound quality?
I'm using a microcontroller controlled MP3 player called a Flyron FN-M16P, which features both terminals for powering headphones (terminals 4& 5, with GND terminal = 7), as well as an amplifier circuit for driving a 3-watt speaker (SPK+ = terminal 6, SPK- = terminal 8).
I want to have my device play MP3 files to the speakers under normal circumstances, but disconnect the speakers and play to the headphones when headphones are plugged in. Please see the diagram here enter link description here
I cannot ground SPK+ and SPK-, the manufacturer tells me that this would blow the amplifier.
My initial idea was to use an SMD 3.5mm stereo jack with isolated NC (normally connected) switch, to disconnect SPK+ (Please see my attached diagram), but I cannot find an SMD 3.5mm stereo jack with isolated NC (normally closed isolated switch). I want to avoid PCB parts. I have found an SMD 3.5mm audio jack with an isolated NO (normally open) switch from Technik.HK. Please see the link here enter link description here
Can I use a mosfet based circuit to disconnect the 3-watt speakers from the amplifier pins when this switch gets closed without having it introduce any loss in audio quality? How would I do that (I'm a mechanical engineer not an electrical engineer).