Hum caused by a pyramid mixer - Pyramid Music

I doubt the issue will be the regulators if you have the correct voltage on them.
Check where the hum is coming from.
What frequency is the hum; 50/60HZ = mains hum = bad ground. 100/120HZ = power supply hum.
Affected by a control somewhere maybe.

Running mixer to receiver??? does the mixer have rca (red & white) audio outputs? if so you can run it that way and hookup to whatever input you want on back of stereo. If it doesn't then you can buy a 1/8" stereo jack to rca and run out of headphone out. (will need a 1/4" headphone adapter though).

I used to be a hi-fi enthusiast many years ago.
A low frequency hum can be caused by inadvertently creating a "hum loop". This is when audio separates are earthed or grounded where they are plugged into the power outlets and then connected together using screened audio leads where the screening is connected to both plugs.
The situation can become worse when one of the separates is a type that isn't grounded.

Ineffective or insufficient power supply smoothing and/or shielding leaving an AC ripple on the DC also creates a hum or in the case of poor design or bad shielding can radiate AC magnetism into the high gain input stages of amplification.

Whatever the cause of the hum it can be aggravated by poor matching of separates with regard to input/output sensitivities and impedances. If the pre-amp stage gains have to be high to compensate for a low input signal the signal-to-noise ratio will always be poor through every stage. Small signals requiring large amounts of amplification requires low impedance circuitry and appropriate sensitivity.

Food for thought...

Hello,

I need a bit more information but from what i can tell it's about the power supply capacitors issue, as this devices are known to develop such kind of humming annoying noise when they go under the specified value, let me know further,
Regards.

What is plugged into your Numark mixer when this happens? Try disconnecting ALL audio inputs to your mixer, turn mixer volumes to zero and see if the hum is still present. Adjust the volume and check if the hum you mentioned returns. If it is still heard, try new cables between the mixer and amp...if not then start reconnecting inputs until the hum is heard again. It's a process of elimination but not that difficult to find the source of your problem.

You say the clip light is always on, as the only clip lights on this mixer are on the effects channel and the master output and you do not say which is on there are a number of possibilities. You may have the effects turned up too far as this should not be showing, just maybe blinking, turn them down on efx2 on all strips as well as on the effects processor and see if this helps. If it does you may be able to find where the hum is coming from by gradually increasing each until you find it.

If you are getting the clip on the main mix master and you are not being deafened and the humming sound is coming from the speakers not the mixer you may have a subsonic signal getting into the mixer. Disconnect all inputs and if this cures it go through until you find where it is getting in and sort that.

If the humming is coming from the mixer it is possible that the smoothing caps on the PSU are dying, you do not say if you are getting normal sound as well as the humming from the mixer.

When asking for help please try to give as much information as possible

If you are experiencing a mid-range humming from your monitors when using your Allen & Heath PA12-CP mixer, there may be a problem with the signal level or the cables.
Here are a few steps you can try to troubleshoot and resolve this issue:

1. Check the signal level of the sources that are being sent to the monitors (e.g. kick drum, snare, etc.). Make sure they are not too loud or too quiet, as this can cause the limiter to engage and create a humming sound.
2. Check the cables that are connected to the monitors. Make sure they are not damaged or loose, and that they are properly connected to the mixer and the monitors.
3. Try using a different set of monitors to see if the problem persists. If the humming is still present, the problem may be with the mixer itself.
4. If you are still experiencing a humming sound, you may need to contact Allen & Heath customer support for assistance. They will be able to provide you with more detailed troubleshooting steps and help you resolve the issue.

Overall, if you are experiencing a humming sound from your monitors when using your Allen & Heath PA12-CP mixer, the problem may be with the signal level, the cables, or the mixer itself. Follow the steps above to troubleshoot and resolve the issue.

Incorrect connections or volume settings.

• In powering up, mixer first then amp

• In turning off , amp first then mixer


If hum still persist, without the mixer connected

then speaker amp may need servicing.

This sounds like a ground loop. Make sure ALL (including the computer) interconnected devices are powered from the same receptacle. Make sure there are no lamp dimmers around as these can cause hum...

If the hum is observable in headphones, then it is likely a power supply problem, usually a dried out electrolytic filter capacitor.