Power hum: Denon AVR 2307 connected to PC's sound card

[rvlog]

I have a 50 foot RCI-to-phonojack connection between my Mac's sound card line-in and my Denon AVR 2307's tape deck output. The cable is an off-the-shelf unbalanced - ie. not shielded against RFI (Radio Frequency Interference) and EMI (Electro-Magnetic Interference) - type. I want to use it to archive my record collection (I bought the 2307 for that purpose, among others).

When I had the turntable ground connected to the Denon's chassis ground, I was getting a lot of hum through to the built-in sound card. Then I disconnected it and the hum was better, but still too much. The volume of the Denon is set to zero dB and the sound card input level is also set to zero dB. I am using Pure Vinyl for the archiving. The record input level meter shows a -50dB hum when there is no signal input from the receiver.

What are the options to try and shield the interconnect from EMI and RFI? Is there a simple solution? Will balanced cables solve the problem? Please can anybody help?

 

[spooney]

All PC cards hum except the expensive professional models.
Your long inexpensive cable will add noise. There is not much you can do as the source is the PC card and the cable acts as amplifier.

What I suggest is to aquire a PC phono preamp. They are relatively inexpensive and will suit your purpose. If you check out some software vendors (e.g. Magix Cleaning Lab, the one I use): They offer a bundle with cleaning software to get rid of hum, crackles, etc.