RK@
As Manoj said, It is the time to change the Home theater. Since there is no other sound output options available other than optical in TV, you can try any of this below.
No cost option
If you are not interested to spent for Home theater and you are only using DTH/STP/DVD, then you can straightly connect the sound output of this devices to home theater using the ordinary audio/head phone jack.The cons are
* you have to change the inputs of HT through remote.(If different input options are not available in HT, then you have to manually change the connections each time.)
* You cant connect TV output to HT, so you have no option, if you watching movie through the USB port in TV.
Converter Option
It is costly and nothing available in market other than the products in online sites.
There is no guarantee in sound quality.
Changing the Home Theatre
* it is the best option> Today most of the Home theatre products range starting from Rs.5K have co axial/optical/stero/dolby inputs.
2 years before i bought a Airtel HD DTH connection and to experience the DTS sound output of HD channels, i had no option in My home theatre, though it had a 5.1 input which i using for my DVD. I bought a Mitsun branded HT which has so many input options(2 stereo jack input for TV & Aux, 2 co axial inputs which i connected to DVD & HD DTH, 2 optical inputs & 1 Dolby 5.1 input) and good sound output with High Bass. I cant use the half of its volume in my home.When i increase the volume more than that most of the windows, doors & mirrors starts to vibrates.It costed me only Rs.9K.the exact model i selected was not showing in the site though, i posted the link of a variant which almost look alike. Mine was the topend product of their at tht time.
:: MITSUN ::
MIT-X11 (11000W PMPO)
the thing i like in My HT is, when i change channels in DTH through remote(HD channels to Sd channels), My HT automatically change to DTS/Dolby/Pro(Stereo) as per the input(which we can see in HT display) which gets from DTH [a single pair stereo jack(the ordinary L R jack. 'red jack to DTH co axial output & white jack to DVD co axial output. The other end of these jacks to the coaxial 1 & 2 inputs of HT ) i used to connect to HT from DTH and DVD as co axial inputs]. Like the same whenever i use USB/DVD/CD or change the sound output in DVD also.