Hi all, thanks for having me in this forum, it’s been a long time since I was actively set up with my system. I have a Thorens turntable and Pioneer CD player connected into a recently purchased NAD 3140 amp. The turntable is great through the phono input. My CD player is fine through either Tape 1 or Tape 2 input but when connected through the Aux input, which is where I expected to connect it, there is a hum through both speakers. The hum increases according to the volume control and is the same volume in each speaker. It is a great amp and I have both Tape inputs for a CD, cassette etc so it’s not urgent to fix but what do you suggest could be the issue on the Aux input, how to locate the fault and how to fix it ? Thanks
Welcome to the forum!
Taking a guess, you may have defective grounding of the Aux input jacks.
Any easy experiment: play music into the Aux input and use a short length of hook-up wire to connect the shield/shell of the AUX jack to an adjacent shell jack known to be behaving normally, eg. a Tape input jack. You can just hold the ends of the wire in contact with your fingers. If hum clears, you've confirmed a ground defect. An ohmmeter check should show poor ground continuity between Aux and Tape jacks.
Assuming this is confirmed to be the issue, use your ohmmeter to search the interior for the open connection.
Good luck!
Taking a guess, you may have defective grounding of the Aux input jacks.
Any easy experiment: play music into the Aux input and use a short length of hook-up wire to connect the shield/shell of the AUX jack to an adjacent shell jack known to be behaving normally, eg. a Tape input jack. You can just hold the ends of the wire in contact with your fingers. If hum clears, you've confirmed a ground defect. An ohmmeter check should show poor ground continuity between Aux and Tape jacks.
Assuming this is confirmed to be the issue, use your ohmmeter to search the interior for the open connection.
Good luck!
Exactly that. Could be cracked solder joints on the aux terminals. Or just oxidation, try cleaning the terminals with some de-oxit.
