"60-Hertz hum that comes from

There are parts in electronic music devices that change the electricity and filter it. The parts age an lose the ability to do that.

Power Supply.
Probably the Filter Capacitors.
Get them changed by a Tech.
Enjoy

AC hum comes from poor grounding of components.

If it is a tube amp, the tube finals may not be producing enough free electrons from the heater and should be replaced.

The same can be true of the preamp tubes as well, but they also tend to become more noisy.

If it is a solid state amp, Or you just retubed a tube amp Check to see if the filter caps are begining to fail. These will usually reveal themselves as more 50 or 60 Hertz hum or harmonic thereof depending on the mains frequency and which cap is failing. While not highly likely, it is also possible the power transformer is failing- but it will produce a burned smell if it does.

may be one of the electrolytic capacitors in the power supply has become leaky...this is a common problem among amplifiers...so you let it cool down..then after a period of time the capacitor heats up and then causes the hum...the power supply caps filter out the 60 hertz ac line noise...which is probably the frequency of the sound it is making...this is a good indication of these caps going bad....another thing you can check is to see if the amp is properly grounded(eg: the ground pin on the plug is present) and that you dont have an open cord or input

I assume you are using condenser mics as you would NOT be using phantom power with any other type connected or other devices plugged in while you have phantom power. It is important to have ALL interconnected equipment, including the computer, powered from the SAME receptacle or power source. Make sure the power supply you are using is SPECIFICALLY for the unit from Focusrite as some supplies have filtering within the wall transformer module and others do not. The power supply MAY be generating magnetic fields... try moving it around and see if hum is affected. The capcitive coupling in a power supply can let in higher frequency components from lamp dimmers. Make sure you have no lamp dimmers anywhere near the equipment.

If this monitor is humming without nothing connected to it, maybe the electrolytic capacitors from its power supply are bad - they are responsible for filtering the fluctuation at the output of the internal voltage rectifiers that transform the AC input voltage into a DC voltage to feed its internal amplifier.

When they fail, the supply voltage for its internal amplifier that should be flat, continuous, now presents a pulsating profile, according to the mains frequency (generally 60 or 50 Hz, depending on the country you're in). So, the output of the amplifier will be varying at the same rate, producing the humming.

Another possibility is that one internal cable connection that should be shielded is now disconnected or loose and is picking the hum from the internal power supply.

Anyway, maybe you should take it to a service center and have it checked.

Hope this info may help you!

Of course it is repairable.

Find a competent repair person. You did not describe the "noise". If it is 60 cycle hum, the filter caps need replacing. If it is an organ tone, then probably a key contact is stuck.

Chances are you're hearing "60-Hertz" hum that comes from poor filtering in the organ power supply. Electronic circuits need direct current (DC) but our power lines supply alternating current (AC). The power supply converts the AC to the various DC voltages needed. Parts called filter capacitors smooth out the voltage, and if they go bad or lose contact because of bad connections the result can be the hum you're hearing.

There are other possible causes, but the filtering is so common it's a good place to start. You don't give the age of this organ, but if it's one that has been around a while, it's a good bet some of those capacitors are worn out.

If you can post a follow-up with a make and model, I'll check some of the technician groups and see if anybody has service information.

Good luck and thanks for using Fixya!

Probably needs the filter capacitors in the power supply replaced.

The electrolytic caps dry out after years and become ineffective in filtering to get pure DC current for the electronics.

Other less likely possibility is a broken ground wire someplace within.