I've moved into a new apartment have a new setup with my record player where, out of necessity, across the room from my receiver and speakers.
I've got a Music Hall MMF-5 and a Rotel receiver, with B&W speakers. I've run about 25 feet of extension RCA cords to connect the record player to the receiver. The receiver and record player are plugged into different outlets, completely across the room from eachother.
When I turn the receiver to the phono input, it generates a loud buzzing, regardless of whether the record player is on or not. No other input for the receiver has any buzzing and other things work fine on it.
The MMF-5 has a ground cable (a little horseshoe-shaped metal thing) that I used to have screwed into the ground screw on the back of the Rotel, but now I can't because of the distance. I assume that is what is causing the buzzing.
I tried to fashion a "ground extension" cable by using speaker wire to connect the ground to the receiver, but it did not fix the problem at all.
To begin with no turntable should be positioned that far away from the receiver/pre amp input. If you're running a moving magnet or high output moving coil cartridge, the capacitance of the cables will be far too high no matter which cables you choose and the sound quality will be affected in a negative way. If you are running a low output moving coil, the distance the signal must travel should always be mininized or you risk serious degradation of the levels across the frequency bandwidth and therefore poor sound quality.
Yes, you will in almost all cases need the ground cable. You're grounding problem is most likely caused by the two components - receiver and table - existing on separate circuits running from your AC service box.
For many reasons place the table no more than one meter from the input and chances are your problems will be solved.
Thanks for your reply. Unfortunately given a really strange setup in my new place, I don't really have a choice and need to have the phono across the room (25 feet if you measure the wire along the walls, but really only about 8 feet away from the unit)
So I really can't get it within a meter - ruling that out, is there really no way to solve the buzzing? I had hoped creating a ground extension would work, but for some reason it's not.
MM, yo could try grounding the tt wire to the center screw of the recepticle cover, then fashion a ground wire from the receiver to its wall plate. This may help, but will not fix, your problem. The 1 meter that JV quoted is for a reason. You are dealing with incredibly small voltages and cables that are prone to pick up interference. I doubt that you ued shielded cable, in one piece for the 25' extension, but even that is a bandaid for location, location, location.
First, I would be certain the table works as it should in a more normal location after the packing and unpacking and new set up. You want as few distractions to the problem as possible so do this before you try to solve a problem that might not exist where we have guessed. Move the table close enough to the receiver to use the supplied OEM cables and be certain you have no further grounding issues after the move.
If that proves satisfactory, then you can proceed to solving the ground loop issue in your "other" location. There are no simple rules for grounding issues once you've broken the main rule which in this case is location. About the only thing to advise with any confidence is try only one thing at a time and keep records of what worked and what did not. If you ground the table to the center screw of the AC outlet, only ground the table and then check for improvements. If that solves the problem or simply reduces the noise by a considerable margin, then proceed to grounding the receiver in the same fashion. If one tack doesn't work, that doesn't mean it might not be an improvement once you've made another change. For the most part grounding problems become a suck it and see what comes out sort of affair.
I would suspect your problem is related to the two components being on different circuits running from the AC service box. That could lead to several solutions that might solve the problem. First, determine whether the two outlets are fed by different circuit breakers by simply flipping the breakers to the outlet that feeds the receiver. If the table still operates, then you know they do not share the same circuit. If you live in an appratment that has no access to the breakers, you can buy an inexpensive circuit tracer at most home improvement stores and check the outlets. If this bi-circuit circumstance is the case, you can make either temporary cures by using a decent quality extension cable to place both components on one outlet or a more permanent fix by having an electrician re-route the one circuit. If you run an extension cord to the table, you might risk more noise by running the extension too close and in parallel to the cable running from the table. You must have a high quality shielded interconnect - no zip (lamp) cord connected to RCA's - running from the table or you will have no chance of solving the noise problems with or without the AC extension cord. When such AC/interconnect runs are made out of necessity it is advisable to make any cable crossing at a 90 degree angle and never run the two cables in parallel to one another. So maybe you want to run the extension cord around the other side of the room, which you should try out before you give up on the idea.
As you can see solving grounding problems is not simple or easy. Place "solving ground lopps" in a search engine to get some other ideas on how to go about this. There's not much more we can do for you as this becomes a try this and then try that approach. If you become absolutely frustrated by the whole affair, you might reconsider just where the table/system can be sited.
One other solution would be to buy an outboard phono pre amp which can sit next to the table. The cable run from the phono pre amp to the receiver is line level and far less suspectible to noise issues. You could view this as an opportunity to upgrade your phono section and not mess with all the searching out of your grounding issues.