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60 Hz Noise Reduction

How do I eliminate 60Hz hum from my audio system?

HISTORY:
I recently purchased an Acurus A200 to increase the volume level of the front channel of my second system. When I connected the unit I noticed a 60Hz hum coming from both front speakers. I'm thinking the new set up has created a ground loop, or the units with no AC ground plug (2 prong AC plug) have a floating ground. The 2 prong AC units are Denon AVR3805, and Velodyne ULD15. So I would like to get some ideas of things I can do to eliminate the 60Hz hum This set up is a hodge podge of equipment left overs from the past.

OLD SET-UP (No 60Hz Noise)
Denon AVR3805 driving front, center, and surround speakers.
Denon preamp out to ULD15 controller/amp driving ULD15 sub.

NEW SET-UP (60Hz Noise)
Denon AVR3805 reciever which powers center, and surround speakers which are Monitor Audio bookshelf speakers. Denon pre-amp out to ULD15 Series II controller/amp driving Velodyne ULD15 sub. ULD RCA output to Acurus A200 amp input driving Monitor Audio GS10 for front.

Ideas Appreciated
Aaron
aweaver555
jea48
4,408 posts
 
Just guessing you have a CATV box connected to the system. Disconnect the coax cable from the CATV and check for ground loop hum. If hum is gone buy an isolation transformer for the CATV coax cable.
http://www.jensen-transformers.com/an/generic%20seminar.pdf

http://www.jensen-transformers.com/an/an004.pdf
rudd
51 posts
 
Same thing happend to me years ago (60hz hum) and the answer was the Jensen transformer. I paid approx $50 and never looked back...
aweaver555 OP
5 posts
 
Hi Rudd,
no cable box just TiVo.
Wow I would have never thought about low frequency noise coming from a cable box.

Just curious where did you place the jensen transformer, and which model for future reference.

Thanks Again
Aaron
aweaver555 OP
5 posts
 
Great article on noise isolation/elimination very helpfull.
I think I nailed it by attaching earth ground to Denon Receivers chassis ground.

Definetly will keep the Jensen ISO MAX CI-2RR isolation transformer for any future noise issues.

Thanks So Much
Aaron
jea48
4,408 posts
 
no cable box just TiVo.
Aweaver555
Where does the TiVo receive its signal from?

I think I nailed it by attaching earth ground to Denon Receivers chassis ground.
Aweaver555

Not a good idea. If the Denon has a two wire polarized plug that means the equipment was designed and manufactured with double insulated ac power wiring, therefore an equipment ground (third wire) is not used. An earth ground connected to the chassis could degrade the sonics of the unit. More than likely the signal ground of the unit is connected to the chassis. By earth grounding the chassis EMI/RFI AC noise could enter the electronics of the unit through the ground wire.

Jensen VRD-1FF

http://www.jensen-transformers.com/datashts/vrd1ff_manual.pdf
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