I tried to connect my turntable to the HT770 receiver via a pre-amp and get a lot of hum. I have not grounded the turntable and this should help. How can I easily accomplish this and will this eliminate the hum?
Well - your info is a little vague. What pre-amp are you referring to ? Sure you have to ground the turntable - ground it to the pre-amp chassis - just touch the ground wire to the chassis and you should hear the hum disappear. But does this pre-amp have a phono input and how are you connecting the pre-amp to the power-amp section of the receiver - assuming this can be done. I don't have the Onkyo receiver.
Somehow I don;t think your setup works but if you are getting sound and your only issue is modest hum then chassis grounding should solve it.
By the way, the Onkyo receiver does not have phono inputs so you must run the turntable through the Tape-in inputs. Since the turntable did not have a built-in preamp I had to purchase one. I connected the turntable to the preamp and the preamp to the Tape-in inputs. I am now getting sound, but a lot of hum.
Is the DTS mode available only with a digital coaxial cable?