Amp and problem on bass frequence

Hello to all,

I have a question related to my amp. It's little Randall RX15. On those links you see the RX15M but it's basically the same thing.

http://www.randallamplifiers.com/products/amplifiers/rx/index.asp#
http://www.randallamplifiers.com/products/amplifiers/rx/images/zoom_rx15m.jpg

The guitar used with it is my cool red Ibanez GAX30 and my nice Takamine EG440C.

Maybe it's a normal behaviour but here I go. When the equalizer is set low on bass frequence everything is fine. But if I but the level beyond 6 I can hear a fuzz tone in the sound. In other words it's not a clear sound with more bass but it sounds like the broken speaker. I don't think it's the case becaues it's like new. Please note that I did tests with the middle and treble at 5 and on the clean channel.

I know that's a little amp for praticing and it's nothing high quality. But I ask you guys what you thing about it. Is it normal with those kind of pratice gear?

Thank you for helping

Much as I hate to say it, you probably need to have the speaker looked at. It sounds from the description that the speaker 'paper' has been torn or let loose somewhere. Your speaker shouldn't do that even up to 10 in the bass EQ...Either that or Randall did a bad job of speaker choices and I don't think Randall woulda done that.

Just my thought.

JeffS65,

Today when I played the problem was almost disapeared!! I am pretty sure that the problem is related to the devices plugged in the outlet with my guitar amplifier. There I have a power bar for the computer with computer, monitor, computer speakers, a lamp, etc. all plug in. So I think it can cause so noise that the amplifier amplify... and the power outlet is at 60Hz then it's low frequencies. I remember that when I notice the problem the computer monitor was on. But well you know sometime strange things happen! To conclude when I'll have time I'll try my Randall amp plugged alone.

Thanks for your time dude

Welcome to the wacky world of EMC! :)

ElectroMagnetic Compatibility is the ability of electronic equipment to operate without interfering with other equipment, while resisting interference from other equipment.

As you have discovered, different pieces of gear often interract in unhappy ways. Computer monitors, especially the big CRT types, are notorious for coupling noise into guitar pickups. Using separate outlets for your amp and monitor can help to reduce conducted interference reaching your amp through the power cord, but there still may be radiated interference from the monitor reaching your pickups and/or jack cord.

You may find that keeping as much distance as possible between your guitar and monitor is enough to reduce the noise to a tolerable level. Turning to face in different directions as you play might also help you to find a 'sweet spot' where the noise goes away. As a last resort, you may find that the only solution is to shut off the monitor when you play.

Or you may find that the problem is caused by something else entirely. Fluorescent lights are another common source of noise in an electric guitar rig. Or dimmer-switches for incandescent lights. Or anything that uses an electric motor with brushes.

First try your guitar and amp with everything else in the room turned off. If there's no noise, then you know the source of the problem is most likely in that room. Start turning things on, one at a time, and checking for noise each time. You should be able to track it down this way.

Lordathestrings, thank you for the nice reply. I'll try your recommendations.