Dealing with Earth Loops - Roland VS-2480 Tech Support Help Site

Dealing with Earth Loops

The most common problem in any studio set up is the earth loop. This tiny annoying problem causes that humming drone to appear, either on power up, or during recording.

To be dealt with effectively, we have to start by removing each piece of equipment, until we hopefully find the cause of the problem. If we do, then we can simply remove the earth wire of the offending unit. This should deal with the problem immediately.

If you cannot find the source this way, then the problem can lie with your choice of cables. Very few home studio owners consider the importance of not just high quality cabling, but also using balanced lines throughout.

Any external units, be they FX or rack synths, are generally unbalanced outputs. If this is the case, then I strongly advise the use of Direct Injection boxes (D.I.) for recording. This will ensure that the signal reaching the 2480 is balanced, and free of any external interference. If the outputs are balanced, then use standard TRS cables for ensuring balanced line cabling to your 2480 inputs.

If the problem is still not resolved, then we need to take more extreme measures.

Any studio set up, home or commercial, should only share one earth connection. In larger studios, the actual current draw (amps) is normally shared over several independent power line servers, or courses. Lights will normally have a 10 ampere line, FX, the mixer and recording mediums will use a 16 ampere line. If more is needed, then an additional line will be used of 16A or 20A, depending on the source (heavy power amps for example, or, surprisingly enough, heaters).

Normally, all earth connections to the installed studio equipment will be physically removed - all but one, and normally the Power Amp driving the control monitors. In the home studio set up, I have removed all my earth wires, except the 2480. All my power cables are connected to a major power extention (plug board), which in turn is connected to a genuine 16 Ampere EARTHED line.

So I have zero earth loops, and if anything serious should occur, the worst that can happen is that my 2480 internal PSU fuse will blow, or the house earth-trip switch will flip. Just remember when choosing your main Earthed Power Source, that the fridge or freezer is not on the same line!