Connecting optical audio from freeview box to L/R audio on surround system. Help!

Hi all.

My first post on AV Forums! Here goes....

I have a Daewoo DSD9502T twin-tuner freeview recorder & a Philips HTS3100 All-in-one DVD player and surround system. My Daewoo freeview box outputs appallingly tinny (high treble) audio via the L/R audio out and the Scart. The optical output on the other hand seems to output a much richer sound (more bass), which I briefly experienced on someone elses surround system that had an optical input. Unfortunately my new surround system doesn't have an optical input. I would love to be able to output the optical signal from my freeview box to the surround sounds L/R audio input (these are the only audio inputs that it has). Is there anything that I can get that will allow this? I can't find any type of cabled converter out there. Is there an affordable junction box/AV converter that would do this, or can anyone suggest a workaround?

The tinny sound from the freeview box is very annoying - it results in a hissy sound from the speakers when there is high-end treble (eg crisp vocals), and is very off putting. The lack of bass is also annoying.

Any help or guidance would be REALLY appreciated!

Thanks. Jme