Buzz....hum problem from turntable....

The hum of course is the 60 cycle line AC voltage. Make sure that the routing of the AC power plug is as distant as possible from the stereo RCA cables.

The most likely problem is the connection of the phono cartridge to the wires in the arm. These connections usually are silver plated and become oxidized creating a bad connection. Remove the cartridge and using a fine eraser polish the connections. There is a ground connection that makes the five wire connection. Be super carfull these terminals are very easy to break

The phono connections to the stereo is very low voltage subject to interference. The connection to the magnetic pickup at the tone arm is low impedance and is inductive. Any poor connection between the cartridge up to the AV316 will produce this hum. Continue to check connections and swap cables with a known good to resolve.

I have switched the left and right cables to ensure that the cable is not the problem.

Hope this helps?

The preferred approach is to run a ground cable from the turntable to the ground post on the back of your preamp or receiver. This keeps buzz and hum out of the audio signal. If your receiver doesn't have a ground post, you'll have to connect the ground to one of the RCA signal jacks. In both cases the question is, when you have two grounds, which one to connect? You'll have to determine this by trial and error. My guess is you'll get the best results by connecting both, so start with this arrangement. Connect the turntable's audio cables from its RCA jacks to the receiver, select the phono input, and turn it on (with the volume turned down). Turn up the volume until you can hear hum or buzz. Then connect a piece of wire to the ground post on the turntable panel and touch the other end to the ground post on the receiver or to the RCA jack/plug's outer ring. If the hum/buzz goes away, you're good to go and can connect the wire permanently. If not, try the ground cables individually and use the connection that works best.

The ground wire needs to be attached. The hum is a result of a bad ground.

Turntables require a special input in the amp (usually marked PHONO) because they require high gain and different equalization - and yes, that ground wire has to go to ground unless you want to get a super annoying 60Hz hum from it!
If your amp doesn't have a phono input, you're going to have to go out and get a phono pre-amp and connect it between the turntable and the amp.
Best of luck!

Hi, The Ground Rules Of all the annoyances that can afflict any audio/video home theater or even a simple stereo installation, the notorious "ground loop" may well be the most difficult and persistent one to track down and eliminate. A "ground loop" is caused by the difference in electrical potential at different grounding points in an audio/video system. (All the grounds in an A/V system should ideally be at "0" potential.) A ground loop typically adds a loud low-frequency hum or buzz as soon as you plug in any of various audio or video components, including subwoofers, cable-TV outboard boxes, satellite-TV feeds, TV displays, amplifiers, A/V receivers or turntables. The buzz/hum is a byproduct of the multiple power supply cables and a ground voltage differential within your system and its network of interconnecting cables.

Here are some methods to help you get rid of ground loops. Try these first and don't waste money on a power "conditioner" which, in most cases, won't help. (There is no need to "condition" the AC power for your system. Your receiver or amplifier already has a power supply with its own filters and transformers. No further filtering is normally required.)

If you get your system up and running and hear an audible buzz or hum, the first culprit to look at is either the powered subwoofer or your cable-TV or satellite-box feed at the entry point to your system.

First, the subwoofer: unplug the coaxial cable that connects to your powered subwoofer to see if the ground-loop hum disappears. If it does, it's likely coming in through your cable/satellite TV feed.

Reconnect your subwoofer's coaxial cable from the subwoofer input to your receiver's subwoofer output and disconnect the cable-TV feed (or satellite feed) from your outboard set-top cable box or satellite tuner. Be sure and disconnect the cable before any splitters. Now see if the hum/buzz from your subwoofer stops.

If that eliminates the hum, you can install one of these inexpensive in-line ground isolators from Parts Express or Bass Home. Note that these transformer-based ground isolators will work fine with analog cable-TV feeds, but depending on their design they may interfere with or block reception of HDTV signals via a digital cable or satellite dish feed.

Install the ground isolator between the cable-TV feed and the input of your outboard cable-TV box or satellite tuner (or the TV display's antenna or cable input if you have a set with a built-in TV tuner or a cable-card ready set). In many cases, the ground isolator will "break" the loop and remove the annoying hum or buzz by isolating the TV-cable ground.

If a hum remains with the TV cable completely disconnected from your system, or you don't want to risk degrading reception of HD signals from a cable or satellite system, then you may have to add a ground isolator like this Radio Shack Model 270-054 between the line-level coaxial subwoofer cable from your A/V receiver and the line-level input jack on your powered subwoofer.

In all cases, if your subwoofer has a ground-lift screw like some of Axiom's subwoofers, try first removing the screw (or replacing it) to see if it increases or eliminates the hum. It may or may not make a difference.

If you do not have easy access to the aforementioned ground isolators, here are a few more tips:

Try plugging the subwoofer into a different AC outlet in the room, one that isn't supplying power to your components (A/V receiver, TV, cable box, etc.). That might fix it.

Try reversing the AC plug for your A/V receiver or the powered subwoofer. If it's a 3-wire plug or a polarized plug, which has one prong wider than the other, you won't be able to reverse the plug. For safety, do not use a "cheater plug" to bypass the 3-wire plug.

With the power OFF, reverse the AC plugs one by one of any other components that have a standard 2-prong AC plug that isn't polarized. Each time you reverse a plug, turn on the system with the attached component and your subwoofer and see if the hum disappears. In some cases, reversing one or more plugs will eliminate the hum.

If you have a turntable, try connecting a separate ground wire to a chassis screw on your preamp or receiver and see if the hum disappears. If you already have a turntable ground wire, try removing it from the preamp. One or the other may eliminate the hum.

Finally, here is another solution that worked well for a member of our message boards who decided to discard his ground-loop isolator on his subwoofer: "I took off the ground-loop isolator I'd been using and connected a plain 14-gauge wire to chassis screws on the sub and the receiver then powered everything on. Although hum was still there, it was far lower than before. Next I unscrewed the ground-loop screw on the back of the sub and that took care of the hum completely."

Almost certainly sounds like an earth loop to me, but can be caused by a poorly made transformer or phase shifts on the mains supply. Visit some power conditioner web-sites like Isotek or Isol-8 (or google "earth loop") where there's plenty of advice on how to reduce/eliminate earth loops and other causes of mains-induced hum (transformer problems etc).

Hum on the speakers usually indicates that there is a DC voltage on the speaker line. DC voltage on the output lines would be caused by a shorted output transistor.


Have a nice day...

The red wire is the right channel, so going back to your amp, get a single phono plug with with the wire exposed, so you can touch the wire. Then remove the turntable connections. With the amp on plug the the lose wire plug into each channel and check if the sound on the right is still low. If it is then there's a problem with the magnetic cartridge pre-amp inside the amp. They are often located near the phono socket on a seperate PC board, but if not just follow the red wire to the main board. Chances are it will be an IC that's failed.
If it has a strong buzz at the back of the amp. Then I should replace the wire between the turntable and the amp. Or the right phono plug that connects to the amp.

grounding might solve the problem but you have to replace the connection cords from your marrantz to the turntable... maybe they are the one thats causing the humming.... they may be loose

Just a suggestion, make sure the power outlet/s is grounded and that the polarity on both plugs are correct.

Tan Orexic

Hi!

I'm not sure what you are asking. The ground loop is specifically intended to reduce or eliminate buzz/hum from the turntable. If the ground loop is in place and connected as per the instructions with your turntable/receiver, these noises should not be an issue in a modern system. I would make sure that your connection is solid and at a good ground point (easy to check if you have an ohm-meter/multi-meter (which comes in handy for many things and can be had very inexpensively). If the wire is broken, it can be replaced with any wire of the same or heavier gauge.

If I've failed to understand your problem, please post more detail and I will try again. If not, please let me know if this is helpful. Good luck with your problem.

Bob

Yes first check is that the Gnd wire from your turntable is connected to the Gnd (ground) post at the back of your amplifier with a good clean tight connection.
If the problem persists, check ALL your hi-fi components mains plugs for earth connections including your turntable, then remove the earth connections on all but one component so that you are left with only item earthed.
What does sometimes cause problems is if 2 or more hi-fi separates are earthed and connected to each other the earth cables along with the hi-fi interconnects form an inductive loop that picks up interferance such as mains hum etc.
Regards John