OK, I do have some help for you guys.
There are several different issues here so bear with me.
ALL have been dealt with in previous threads, but I will try to go through it all again.
The ZX-500 has a built in ANALOG TV tuner. The TV tuner on this unit WILL NO LONGER WORK as all over the air signals are now digital.
There are two ways to make it work
The over the air antenna output from the wall plate must be connected directly to your Digital TV (and not the ZX-500).
If you do NOT have a digital TV, you will need a converter box between the output of the wall plate and your analog television or the ZX-500.
(If you can no longer find a converter box I still have a new one I can sell you)
Getting surround sound audio OUT of the TV to the Concertone.
This one is tricky as some of you have found out.
Surround sound is a LINE LEVEL encoded signal that does not come out of the earphone jack. You can get "stereo" out of the earphone jack and can connect it to the iPod/MP3 player input on most Concertones. You will never get surround sound this way. I do not believe the earlier Concertones have a "theater" setting to make a stereo use the 5.1 speaker setup. I think the later ones do. "Theater" is NOT Surround Sound. It just uses all 5 speakers and the subwoofer.
If your TV, (like mine), has RCA audio outputs, you can connect these to the RCA input jacks of the Concertone. THESE outputs are line level and if the "over the air" broadcast contains surround sound encoding you will get true surround sound out of the Concertone. You will also get true surround sound out of a DVD player connected to the TV since the RCA output jacks will pass through that information.
So, you have a "cheaper" or "newer" TV without RCA output jacks.
Are you screwed?
If NO line level output jacks on your TV, you are limited to the earphone trick.
However, look for a fiber optic/TosLink port on the back of the TV.
This is a digital (not analog like the RCA jacks) output found on newer TVs. Since the ZX-700 and earlier units do not have a fiber input, you will need to convert the digital output to an analog RCA signal to be used by the Concertones.
KanexPro Digital to Analog Audio Converter AUD2ACV B&H Photo
will do this for you but will NOT pass the surround sound encoding (2 channel only).
Looking for the link afraid to lose post.
Sewell Digital to Analog 5.1 DTS/AC-3 Decoder Surround Sound (Toslink/Coax to RCA) - SW-29767, $68.95
will do surround sound pass through and is the way to go if you have a surround sound capable Concertone or Touch Audio unit.
The Fiber Optic/TosLink port looks like this: