Unfortunately, a phono cartridge puts out a
very low level signal, which is amplified a lot by your phono preamp.
On top of that, the RIAA equalization curve used in your phono preamp boosts low frequencies, including 60 Hz hum.
And, to top it all off, a phono cartridge is basically an antenna as far as picking up electromagnetic noise.
In other words, phono cartridges are really
really picky when it comes to picking up hum.
A furniture leg is not "Earth ground" - even if it's resting on cement or even dirt.
Getting a true Earth ground, if you don't have one from a grounded outlet, is not that simple.
You can't get one by "simply touching the ground".
Depending on your local soil conditions, you generally need to drive a solid metal rod several feet into the ground to have a "good ground".
Even that may not be enough if the soil in your area tends to be dry (dry soil doesn't conduct electricity very well at all).
In the old days a solid connection to a copper water pipe would be a good Earth ground - but these days almost all pipes are plastic at some point.
The other thing is that, depending on how your power lines are grounded, the ground itself could actually have hum riding on it.
However, with a turntable, what's more important is how the ground on the turntable relates to the grounds on your other gear.
If you have a separate ground wire on the turntable, try connecting it to a ground point on the preamp.
(Like a ground lug, if it has one, or the shield on one of the RCA connectors, or a chassis screw.)
It's sort of tricky to figure out what the best ground would be... but, if you try different combinations, you'll probably find one that improves things.
You may also find that grounding the preamp, or
not grounding it, helps the situation.
You can also "grab a ground" from even another room.... for example by running a wire from the ground on an outlet.
If you do so, the wire you use doesn't even have to be insulated, but it should be
HEAVY.
For example, a single run of 14 gauge or 12 gauge wire, to the ground on the nearest outlet that has one, should work OK.
(Or you could use a piece of heavy zip cord or speaker cable - just twist both conductors together and treat it like one heavy wire.)
You will also find that a lot of the stuff in your house radiates magnetic fields - which the cartridge itself and the cables in your tonearm will pick up..
Therefore, the
POSITION of your turntable and cartridge will matter, and its relationship to things like wires in the walls, and other equipment.
So, for example, you could try moving your turntable a few feet one way or the other.
You will also find that hum fields are directional.
So rotaing your turntable 90 degrees, even in the same spot, may make a big difference.
It should also go without saying that big power transformers are one of the major sources of magnetic fields.
So moving your turntable as far away from things with big transformers - like big power amps - will often help.
(This will be less of an issue with the new SMPS on our Gen3 amps.... )
I run an integra drx-3 receiver as a pre-amp with all my channels out put via pre outs to emotiva amps. Is there a place on your pre-amp, like a housing screw or some place in particular you choose to run the ground from? I could try this as well, but the nearest receptacle isn't grounded (I run the panamax off a short extension from a duplex in another zone thats basically its own dedicated circuit). Maybe I could ground to Earth on a furniture leg screw or something like that?
