I have nice rig and I used to run the TV into the Pre-Amp and we watched TV with the sound via the amp and stereo speakers.
But two things have happened.  One is out TV went to that peaceful Spare-Parts store in the sky.  The new TV, a Panasonic jobbie, only has an optical out instead of analogue outs.  Not a major disaster but an inconvenience.
Two; more important is an AMP upgrade.  I now have a Pass X150.8 and this has problems. Not sound quality problems, but practical problems.  It takes the best part of an our to warm up and also it runs hot.  In short it is total overkill for the sound quality of the TV.

Solution:  A small integrated amplifier with a Toslink input.  I have a spare sets of speakers (Spendor D1s or Wharfedale Dentons) that will fit relatively unobtrusively in the lounge.  Obviously it is not something I want to chuck a lot of dosh at - we are talking TV quality sound.  

Not sure about the power needed.  I guess something in the order of 50W power into 8Ω.  Preferably a Class D amp, and not large.

Any suggestions?

Spending other peoples money is always fun. Maybe consider a small DAC, this will open up a lot more options on the amp.

picture and sound over freeview and sky seems to have taken a dive lately, while picture and sound over streaming services has improved.

netlfix can be quite good, especially if you a 4k feed with atmos sound.

amazon can look superb with very good sound in dolby digital plus.
tv shows off amazon leave freeview and sometimes bluray for dead.
still stuck with lossy audio though.

nad, nuforce, project and many no-name amps could fit the bill.

or maybe a small avr ?

Hi, I'm currently rebuilding my system since I have just moved house and sold off all my AV gear. In the process I was looking for a DAC that could get me to a point whet I had 90% of my system replaced then try various DAC's so see which fits best. I bought a NAD M51 of Trade Me and to be honest the features are really useful. It has 2 HDMI inputs and as you would expect many other digital options including SPDIF and Coax. It's worked out to be a really good solution as I run a MAC Mini with Audirvana for music via USB, but also can run my Blu-Ray through it as well. It's also a reasonable partner for my Musical Fidelity CD player.

So I'd suggest you look at a DAC which supports HDMI Video Pass through and decoding of 2CH PCM.

I also may have one of those cheap DAC's (like Jaycar) in my office. I'll dig it out and give it a go on my TV (which arrives shortly after the 20th June) and let you know how it goes. Or if you're in Auckland I could let you borrow it. I just need to check we have one in stock..
Steve.