Using both built in speaker and headphone jack

[kb5udf]

Hi all,

I'm stumped. I'm sure this question/solution would apply equally to radio gear and tv's etc, or really anything with a headphone jack and a speaker.

I have a situation where I would like to have BOTH the speakers on my cheapo HISENSE tv and the headphone jack (to send audio
to larger stereo speakers). The tv is in a rental property and tennants are likely to get confused and complain if they have to navigate
an HTR and don't know how. So I need both the TV speakers active and the headphone out to supply the htr/av receiver. no, this tv does not allow a menu setting
to do this. Yes, I am aware of using the optical out, but that's suboptimal for a variety of reasons in this case.

Surely there must be some hack to stop the TV from detecting/muting when I pull audio from headphone jack. Perhaps someone sells a cable that will do just this, but my googling has been unfruitful.

Thanks in advance

JB

 

[KB4MSZ]

There are two ways the detection can occur that I am aware of. The earphone output can have a transistor sensing circuit that detects a bias level current on the earphone jack and then switches off the speakers. The other type is that the earphone jack is physically switched when the plug is inserted, turning off the speakers. In this case, it may be possible to bypass this but you would have to be very careful not to send a power level signal through the earphone jack. Doing so would damage any amplifier applied to this circuit.