Persistant Noise In Two Amplifiers

Timothy Kelly Sr · Post by **Timothy Kelly Sr** » 25 Apr 2020 5:32 pm

Today I was practicing my training on my new Rogue RLS-1. I noticed a noise coming through the VOX AD30VT speaker with the Rogue sitting idle with the volume full up. The noise increases as the strings are plucked and vibrate. The noise goes away as the strings come to rest, but it does not go completely away. The VOX AD30VT is a single tube/modeler type amplifier. The tube gives the amplifier a warm tone like the more expensive tube amplifiers.

The noise was not an actual hum, but more like an buzzing signal. I disconnect the cord from the VOX and plugged into my Peavey amplifier. The noise got more prevalent. I removed the single coil pickup from the Rogue RLS-1 and installed a Seymour Duncan humbucker pickup. The noise was sill noticeable in both amplifiers without any changes.

I connected the Rogue RLS-1 to my Behringer VAMP 2 Virtual Amplifier with the same condition existing. After some tweaking I did notice a drop in the noise when I turned down the treble on the VAMP 2, however the noise was still there. I have not tried this on the two amplifiers.

I have a stratacaster guitar with 3 single coil pickups and a telecaster with 2 humbucker pickups. Neither guitar have the buzzing sound when plugged into either of the three devices.

I have no idea what could be causing the condition. It make practicing very unpleasant.

David Irving · Post by **David Irving** » 25 Apr 2020 7:21 pm

It sounds like the problem is with the instrument rather than any of the amplifiers.

Seeing as putting in a humbucker didn't help, there may be problems with the tone / volume controls on the guitar, or perhaps the output jack isn't making good contact with the guitar lead.

Dom Franco · Post by **Dom Franco** » 25 Apr 2020 9:46 pm

does the noise increase or decrease with your hand touching the strings?

Bill Groner · Post by **Bill Groner** » 26 Apr 2020 12:23 am

There is a ground wire coming up through a hole that needs to be in contact with the chrome plate when it gets screwed back down. Are you sure it didn't fall back into the hole when you took the plate off to swap out the Pup? Maybe you could try moving everything to a different location. I have a light on my nightstand on a dimmer.......the brighter the light, the louder the hum.

Timothy Kelly Sr · Post by **Timothy Kelly Sr** » 26 Apr 2020 7:23 am

David Irving wrote:It sounds like the problem is with the instrument rather than any of the amplifiers.

Seeing as putting in a humbucker didn't help, there may be problems with the tone / volume controls on the guitar, or perhaps the output jack isn't making good contact with the guitar lead.

Thanks David - I found the wiring diagram for the lap steel on this site. I will troubleshoot the noise problem and report back.

Timothy Kelly Sr · Post by **Timothy Kelly Sr** » 26 Apr 2020 7:26 am

Bill Groner wrote:There is a ground wire coming up through a hole that needs to be in contact with the chrome plate when it gets screwed back down. Are you sure it didn't fall back into the hole when you took the plate off to swap out the Pup?

Bill - Thanks for the suggestion. I will look for the wire while I troubleshoot.

Jack Hanson · Post by **Jack Hanson** » 26 Apr 2020 11:18 am

Timothy Kelly Sr wrote:I will troubleshoot the noise problem and report back.

Once you've verified the wiring, be sure the strings are grounded. As Bill pointed out, there should be a ground wire contacting the bridge. Poor shielding in the pickup and control cavities can also increase noise.

Tony Boadle · Post by **Tony Boadle** » 26 Apr 2020 3:32 pm

I've had a similar problem on several occasions, the solution (for me at least) was to change to a better quality guitar lead. I'm surprised no-one has suggested that yet. I've found over the years that less expensive instruments seem to be prone to hums and buzzes, and a cheap lead will often amplify the problem (excuse the pun).

Bill Groner · Post by **Bill Groner** » 26 Apr 2020 4:10 pm

When you say lead, do you mean the cable? If he used the cable he used on the Strat and Tele with no hum, I wouldn't think it would be the cable?

Timothy Kelly Sr · Post by **Timothy Kelly Sr** » 26 Apr 2020 5:47 pm

Same cable different guitars. The nose is only with the lap steel.

So I did some troubleshooting. The tone has the hot wire from the volume outer lug going to the tone center lug. The capacitor (of unknown value) comes off the end lug to the ground of the tone potentiometer. I guess electricity does not care which way it travels. There was a ground wire from the volume pot going under the bridge and making contact. Volume and tone posts, output jack, bridge and metal cover plate are all ground to each other. The pots are small so maybe 250 ohms. I forgot to ohm them out.

After reassembly the buzzing nose has significantly decreased to only slight notice. I have no idea what caused it to diminish. However when striking a string the buzzing can be heard until the string stops vibrating.
Since it is not as predominant I can learn to live with it. Its not that bad when actual notes are being played.

I tried to send a photograph but it failed. I shrank it three times to finally it was 480X360 and still would not load.

Thanks for all the help.

Tony Boadle · Post by **Tony Boadle** » 27 Apr 2020 12:57 am

Bill Groner wrote:When you say lead, do you mean the cable? If he used the cable he used on the Strat and Tele with no hum, I wouldn't think it would be the cable?

Good point, I missed that.

Glenn Wilde · Post by **Glenn Wilde** » 27 Apr 2020 4:45 am

Intermittent distortion like that can be caused by a bad pot or solder joint. I would re-flow all solder joints and if its still there connect the pickup directly to the output jack to rule that out. If the pickup is not the culprit then I'd rewire the whole thing with better quality components.

Jim Kennedy · Post by **Jim Kennedy** » 27 Apr 2020 7:36 am

You may need to clean your ground at the bridge. I have fixed this problem on a couple of Fender guitars that way. If the ground is just laid under the bridge plate, over time, it will press into the wood and oxidation will form. Clean your ground wire and the bottom of the bridge plate. Put a couple layers of aluminum foil between the wire and the wood. Helps prevent the wire from pressing into the wood. It won't show with an ohm meter unless you use have one with a very low range, something less than 1000 ohms. That's how I found it. It does not take much resistance to interfere with a signal that is measured in thousandths of a volt.

Timothy Kelly Sr · Post by **Timothy Kelly Sr** » 20 May 2020 7:34 am

After installing the Seymour Duncan single coil humbucker pickup, I did in fact find the grounding wire had been crushed into the wood and not making a good ground. I tinned the bare wire to prevent oxidation and to provide more bulk, then repositioned the ground wire under the bridge.

Most of the buzzing noise dissipated, however some of it can still be heard when striking a single string and letting it just ring. The remaining noise may be coming from the amplifier since it is a modeling amp. My Peavy transistor amp still retains the AC cycle hiss with the amp being 10 feet away. As stated earlier, my other guitars do not have the buzz noise on the Vox amp or slight hissing on the Peavy amp.

It just may be the components. Electronics is very strange. I guess I will live with what I have for now. Thanks to all who reached out to provide support.