Annoying Amplifier Buzz

**Aravind Bhargav** · Jul-21-2011, 6:51am

I am an Indian Classical electric mandolin player using an 'orange crush 20LDX' amplifier for both practise and performances. I get an annoying hum noise, probably due to lack of proper earthing in the power supply. Previously I thought it was the pickup so I recently changed to a Givson pickup available here in India. I am still getting the hum noise

I even tried a behringer DI box resulting in a dip of my original mandolin sound also.
Some Suggestions please........

**allenhopkins** · Jul-21-2011, 2:30pm

Have you tried reversing the power cord plug in its socket? Sometimes polarity reversal can help. Are there hum-generating devices in the power circuit(s) into which you plug the amp? Fluorescent light ballasts and rheostats ("dimmers") are common hum generators.

You've tried different pickups and input devices, so the hum's probably either in, or closely related to, the amplifier, as you state. I know little (or, nothing) about electrical wiring, voltage etc. in India, so that's about as far as I go...

**stonefingers** · Jul-21-2011, 2:49pm

Although the most common problem is the ground for the amp power, I would expect this to hum/buzz regardless of whether your instrument was plugged in or not.
It is possible that the problem is the cable between the pickup and the amp. If this cable is not properly shielded, or if it is not grounded, it will buzz when you plug it in.
Try switching the cable.

**allenhopkins** · Jul-21-2011, 3:00pm

Duplicate thread here.

**Backlineman** · Jul-21-2011, 3:43pm

Does the amp have the same noise when its turned on, off standby, and nothing is plugged into it? If it's quiet its not the amp. It's something in your signal path before the amp. If it is the amp, and has grounded male AC plug (three prong) try putting a 2 prong "ground lift" plug on it.

**Tim2723** · Jul-21-2011, 7:15pm

A hum or buzz that's electronic in nature usually a job for the repair shop. As was mentioned, try a new cable, but if it persists there's little any of us here can do, since it requires a hands-on inspection by a qualified technician.

**Aravind Bhargav** · Jul-22-2011, 1:24pm

Thanks to all. I'll try the tips and get back.....

**Scott Tichenor** · Jul-22-2011, 1:58pm

Originally Posted by allenhopkins

Duplicate thread here.

I merged the two threads into one thinking it better served our membership and put all suggestions in one central location.

**Aravind Bhargav** · Jul-22-2011, 2:22pm

Originally Posted by Scott Tichenor

I merged the two threads into one thinking it better served our membership and put all suggestions in one central location.

Sorry Sir, for the inconvenience.... I didn't see the equipment section initially. Is there a way to remove a thread once posted? ...

**Dan Hulse** · Jul-22-2011, 2:28pm

Isolate the problem. Is it the instrument, the amp, the cord or perhaps the power supply/outlet or as mentioned other hum inducing electrical issues. Switch cords/instruments/amps or try a different location. Divide and conquer.