Panasonic Plasma TV Onkyo TX-SR674 receiver KEF 5.1 speaker set DVD/VCR combo unit Kareoke machine
DVD signal is RGB, Digi Coax VCR signal is analog Kareoke is analog Vid, Digi Coax (RGB circuit is dead due to a bad older TV) Receiver to TV is HDMI
Is it possible or even desirable to connect all the different signal types to the receiver and try and get them all to go through the single hdmi cable to the TV? Also, I heard from some store clerk that, for Video, the best way is to go straight from the source to the TV and only use the revceiver for surround audio. Is this true? And lastly, can I have audio go from the receiver to the TV in case I don't need surround sound?
Sometimes the video can get messed up going through the receiver instead of directly to the tv, other times it won't. You can try hooking them up both ways and see which way you like better.
The nice thing with running the video through the receiver is it automatically switches the audio and video to the correct source without having to program anything in a nice remote to "change the tv to HDMI 1, change the receiver to DVD, etc etc." You can just press "DVD" or "Video 2" on the receiver and everything is switched correctly. I would try hooking them up directly to the tv and see if you notice a difference. If not, then running it through the receiver won't cause any problems. Your receiver does upconvert all the 480i video signals to 480p through the HDMI output, so the VCR and Kareoke machine may look better run through the receiver and then to the tv.
To answer your first question yes - It is possible to have everything go through the single HDMI cable to the TV, your receiver "upconverts" each signal to HDMI and sends it through the single HDMI cable. It's a setting you need to change, look in your manual Page 45.
For audio to your tv, the HDMI cable will also send audio to your tv, see page 32 and 76 in your manual.
FYI, without using the HDMI cable to your tv you won't have a good way to send audio to your tv. There's a digital optical out port on the receiver, however there is no digital in to your tv (unless you have one that I haven't heard of before). So your DVD and Karaoke machine could not have audio going to the tv unless it was sent through the HDMI cable. You could send the analog audio from your vcr back out to the tv, but only the vcr could send audio to the tv. Your receiver does not convert the digital in signals to the analog out ports.
Yes, I've noticed significant difference in the VCR's video quality between composite (yellow rca connection) video going through the receiver with upconversion and back out via HDMI to the TV vs going straight to the TV. I assume the upconversion is not very good.
I have not compared the video signal coming through the component video connection (DVD) as the quality was excellent even though the signal is being redirected via HDMI. Now I'm questioning if I should compare the video quality with a straight through connection.
For audio, I have two digital audio inputs coming in from the DVD and Kareoke to the receiver and that seems to take care of the surround sound for those two. Stereo audio from the VCR comes in to the receiver using the red and white RCA connections. Dolby Prologic does a decent job with that signal.