Amp buzzes unless the tone is rolled all the way off.

Spanky414th · #1 11-24-2011, 01:32 AM

Me and some friends were doing some practicing tonight and I was borrowing the Traynor Amp that stays at the hosts jam space and noticed a buzz coming from the amp. It was the first time we had really tried out my wife's new Ibanez Mikro Bass with an actual bass amp at a decent volume so I thought maybe it was the input jack or cord or something. So I tried out the bass kicking around and a different cord and got no noise but I also noticed that he had the tone rolled completely off. As soon as you brought it back up it also buzzed. Then I plugged my wife back in with her cable and the buzz went away with that setup also, as soon as I rolled off all the tone.

***?

What happens is as you roll the tone off, the buzz decreases in intensity and then near the end it just cuts completely off. Of course the bass sounds pretty damn muddy and dead like that. You can't really hear the buzz over the rest of the band if you leave the tone up but it's still bugging me.

Any ideas?

All I can think of is dirty input jack on the amp or a ground issue of some sort?

JimmyM · #2 11-24-2011, 03:23 AM

Are the pickups in these basses single coil or humbuckers? If single coils, sometimes you'll get hum from outside sources. I have a couple basses that can get a little noisy like that in certain environments.

EDIT: Just found out the Mikro has one P humbucker, one single coil J. Turn the J pickup off and see if the noise goes away.

RickenBoogie · #3 11-24-2011, 07:54 AM

Which Traynor amp? What cab?

Spanky414th · #4 11-24-2011, 10:43 AM

We tried both pickups, same thing either way. Plus I'm used to the backgound noise you usually hear, it changed depending on what your near or facing. This is pretty much constant. It sounds like a ground thing. Could it be that the amp isn't plugged into a grounded outlet or extension cord? If so it seems weird that rolling off the tone would completely fix it.

I think it's a combo. I think it's the Traynor dyna bass 200.

brendanbassist · #5 11-24-2011, 10:52 AM

If the tone knob on the bass fixes the problem, it seems to me that the bass is the source of the buzz, not the amp.

Pilgrim · #6 11-24-2011, 10:57 AM

Simple but who knows...?

How close was the bass to the amp? Some basses will hum or buzz if you're close to the amp, but are silent if you move 5+ feet away.

cashpoor51 · #7 11-24-2011, 11:18 AM

My computer makes mine do the same thing and newer fluorescent lights with electronic ballast do it to
As soon as I walk away from them it stops
Could be your plugged into the same circuit these types of devices
are on also

JimmyM · #8 11-24-2011, 11:24 AM

Quote:

Originally Posted by Spanky414th

We tried both pickups, same thing either way. Plus I'm used to the backgound noise you usually hear, it changed depending on what your near or facing. This is pretty much constant. It sounds like a ground thing. Could it be that the amp isn't plugged into a grounded outlet or extension cord? If so it seems weird that rolling off the tone would completely fix it.

I think it's a combo. I think it's the Traynor dyna bass 200.

You should never defeat the ground in an amp. It can cause electric shock...trust me, it ain't fun. The fact that it changes as you go through the room means that there's interference coming from somewhere and your gear is likely fine. Get a grounded power strip and see if that helps.

JGR · #9 11-24-2011, 12:58 PM

buzz is high frequency which is why you don't hear it when you roll the tone off. probably a ground issue with the amp, or a shielding problem with your bass, or both.

Spanky414th · #10 11-24-2011, 03:10 PM

K I'll try to answer everyone

brendanbassist, It happens with 2 different basses and 2 different cords. Like I said I first noticed that rolling off the tone worked when I plugged in the owner of the amp's bass and discovered he had his rolled off.

Pilgrim, I took her bass for a while across the room and it was still happening. The bassist who owns the amp and primarily plays through it when we jam stands right beside it.

cashpoor51, There is a florescent light in the room, I can't remember if it was on or not. Possibly though and it wouldn't surprise me if it was sharing the circuit. It's never on when we jam there though and the bassist left his tone rolled of so I figure it something that bugged him too.

JimmyM, I'm not suggesting that we defeat the ground. Read the sentence again. I said maybe it already is defeated and that's why it's happening. Also your misreading the change thing. I messed up and said changed when I meant changes.

When I said "it changes depending on what your facing" I mean traditional noise that the pickups can be effected by. Like computers and such. That happens at home with a different amp. At the jam space it doesn't happen like that. It doesn't matter where your standing or what way you face, it buzzes.

JGR I'd suspect the bass if it happened here or only happened with this bass. Considering it happens with multiple basses and only that amp I'm thinking the amp.

JimmyM · #11 11-24-2011, 03:17 PM

Could be right. Give the knobs, switches and jacks a good deoxit cleaning. If that doesn't work, taking it to a repair shop would be your best bet. You might have lost ground continuity along the way.

bertbass666 · #12 11-24-2011, 03:55 PM

An easy way to check if it's the earth or not is to connect a guitar lead from the unused input socket to the input of another amp. If the buzz stops then the amp isn't earthed. Also, does the amp buzz with the lead in the input but no bass on the other end? No buzz means the amp is OK and the buzz is to do with the bass.

JGR · #13 11-24-2011, 07:13 PM

Its not necessarily that simple as there are usually several local ground points inside an amp for the preamp, power amp, and power supply, any of which can cause issues if they lose continuity. As others have said, clean the jacks first. Then tighten chassis and circuit board mounting screws.

kb9wyz · #14 11-24-2011, 07:24 PM

SGD Lutherie cleared this up for me in another thread. The buzz is electrostatic noise. It is not a problem with the bass or the amp, per se. You may get a vast improvement by shielding the electronics. At the end of the day, though, it will be your power that is the problem. There is probably a ground issue on your house. A bass i was working on buzzed like mad until I shielded it. Same thing with the tone knob. The shielding took that down by enough dB to get the buzz below the noise floor of the amp.

An easy way to test to see of you have a power or ground issue on your house, turn your amp up without anything plugged into it. If you have a lot of hiss with the treble at noon, I mean an annoying amount of hiss, you have a problem in your house. My amp does this in my house to the point I turn the horn off. At church, no problems at all.

Spanky414th · #15 11-25-2011, 02:50 AM

JimmyM

Unfortunately it isn't my amp and is located at a friends house so I don't have constant access to it to try anything out until the next time I can stop by. Next time I'm there I'll at least clean the input jack though.

bertbass666 I'll definitely check that stuff out.

JGR Yeah I had to open up a friends guitar amp that had a ground problem and I reseated the tubes and tightened the input and output jacks and grounds and it's all good now. Unfortunately the bass amp isn't a close friend of mines so I'm not sure he would be into me doing that.

kb9wyz With the electrostatic noise, does it change when you move around the room and change what your facing in the room? Cause this was a constant buzz. I figured adding shielding to the bass would help interference and such but not a constant problem like this. It is an older house that was renovated though so you may have a point with the power or ground issue. I try your test out and see. My wife seems to remember the sound going away or lessening when you held on to the strings so I keep thinking ground but then I remember it happening even when playing so who knows.

I think I'm going to go ahead and add shielding to the bass anyways even if it's not the cause of this issue though cause I know I get some computer noise interference at home and less of that would be great.

Spanky414th · #16 12-12-2011, 05:17 PM

Well I took another look at this situation and I has to be something with the amp or power. It does it even with the florescent light in the room off and calms down considerably when you mute the strings pointing towards a ground issue. It also does it no matter what input you use.

It's not the end of the world since your usually muting and you don't hear it when playing but if it was mine I'd be looking deeper into it.