970 - a MAJOR problem!!! HELP please!!!

Posted by: J Wags

970 - a MAJOR problem!!! HELP please!!! - 10/11/09 11:58 PM

I just purchased a "b-stock" 970. I hooked it up to my new Theta Intrepid amp and got HUGE buzz from my speakers. I mean HUGE - not your standard ground loop. So bad, I was afraid I might have damaged the speakers. After removing the RCA cords from the amp and 970, the speakers no longer buzz - so I assume the amp is working ok (so just the speakers and amp are connected - no preamp). It's just when I attached the 970 to the amp, the buzz returns. I went to install a "cheater plug" on the 970 and noticed there is no 3rd prong on the 970 power cord?! Could this be the issue? I just purchased a full SVS spekaer system as well.
Your input please. I don't know what to do at this point.....I'm confused and frustrated as heck.
Thank you,
Jon

P.S. The Theta Intrepid instructions states the following......
"Please Note: Each channel is a balanced bridge amplifier, thus the negative speaker terminal is NOT a ground, and cannot be connected to a ground or a loudspeaker system with a common ground. Consult your speaker manufacturer to ensure that any speaker in your system that will be connected to the Intrepid does NOT have internal circuity with a common ground. Damage will occur if the negative terminal is connected to ground, or to a terminal of another channel or module."
Posted by: gonk

Re: 970 - a MAJOR problem!!! HELP please!!! - 10/12/09 02:14 AM

The 970 has a two-prong power supply. The first things that I would check are the routing of the wires between the 970 and the amp (if they are against a power cord, that could be creating this sort of buzz) and check any cable TV connection to your system. You might also try to determine if the fault lies with the 970: you could connect a self-powered speaker like a computer speaker to see if the 970 is generating the buzz.
Posted by: XenonMan

Re: 970 - a MAJOR problem!!! HELP please!!! - 10/12/09 03:03 AM

Is you wall outlet grounded? Since you were going to use a cheater plug, it sounds like you have 2 prong wall receptacles. The Intrepids manual is very specific about the requirement to have the amp plugged in to a grounded power supply.
Posted by: gonk

Re: 970 - a MAJOR problem!!! HELP please!!! - 10/12/09 03:51 AM

If he was going to add a cheater plug after noticing the buzz, I had assumed that he had grounded outlets and only planned to use the cheater to "lift the ground" on the 970.
Posted by: J Wags

Re: 970 - a MAJOR problem!!! HELP please!!! - 10/12/09 11:00 AM

Thank you guys!

Gonk you are correct...I was tryiing to lift the ground using the cheater plug.

GREAT idea on the self powered speaker! I'll give it a try and check back you.

As far as the routing the cabels....the "electricity buzz" is VERY bad. It's not your everyday interference type hum. I'll also try really seperating the cables and see it this helps as well.

THANK U!
Posted by: Scott

Re: 970 - a MAJOR problem!!! HELP please!!! - 10/13/09 02:17 PM

Hello J Wags,

Any luck on this or the suggestion I made yesterday?

Keep me posted!

Scott