Loud buzzing when amp connects to guitar

Bad connection? Loose fittings? I used to get a crackle from my amp when I turned the volume or balance knobs. A quick spray of WD 40 down the shaft after removing the knobs fixed it.

I also have this issue. Same crate combo amp. There is a loud buzz emitted only when there is a cable plugged in. Cables and instruments checked good, only possible issue is inside the input of the amp. Popped it open, solders and connections were intact and appeared solid. Anyone have a guess as to why this is happening?

Hi.

If the amp is working, then most of the time the buzz is given by a bad grounding. Test the amp using different wall sockets, and possibly test it in a different home (there may be an earthing problem with the home network). If the problem goes away, then it was the wall socket or the home power network. If the buzzing is still there the problem is with the amp. Check the earth connection at power cord and psu and test the amplifier's PSU components. Check also the audio connections inside the amp (the back of the female jack input sockets). A small contact in there will result in a loud buzz.

Yes, there are several possibilities. First thing is to disconnect your guitar and then plug in the cord to the amp. Expect a bit of hum. If it screeches, then problem is not feedback via the guitar. If it doesn't MAYBE your guitar is "hearing the amp" which the guitar is then a microphone and can feedback. Moving the cable generates electrical noise which can trigger the feedback to start.
If you get the screech without the guitar connected, then TRY a new guitar cable. Make sure it is an INSTRUMENT cable... I have seen some try to use speaker cables or junky 1/4 inch cables intended for home stereo... these will NOT work and can cause the feedback. The next possibility is a broken jack on the amp. This would require repair. The common cause of this is to fail to run the cord through the handle of the amp... one trip on the cord or step on it pulling the plug sideways in the amp and the jack is broken and it is a trip to the shop as well. While on the subject ALWAYS run the cord at the guitar end either through the strap or your belt loop. Cords left dangling keep rotating and soon wear out the plug and also the jack in the guitar and then that has to go to the shop.

You are looking at the WRONG end of the guitar cable. You have a VERY unsafe guitar amplifier OR the mixer that is connected to that mic has an UNSAFE grounding condition.

If your guitar amp is an old one that has a two wire cord and a switch you change to reduce hum, take it in to have a three wire power cord installed IMMEDIATELY. Only plug into grounded receptacles. This is needed to reduce electrical noise and hum but MORE importantly is personel safety.

If the problem is with the mixer and the electrical service to the mixer, better get a professional in to analyze the problem before somebody is injured.

AS A START do this: VERIFY that ALL interconnected equipment INCLUDING your guitar amp iis powered from the same source or receptacle. This includes the venue power amps, mixer, any CD players, etc. Professionals run power back from the stage source to the mixer alongside their snake to avoid just the problem you are seeing. When they need more power at a venue, a power distribution box is used that conditions the building power and insures grounding.

It is happening because you have a ground loop. You need to check the ground on your amp. If it is an old one that does NOT have a three wire cord, you need to have that changed. Failure to do so could also damage the interface. ALL your equipment, computer and guitar am should be powered from the same receptacle. If you have other devices connected to your laptip such as printer, they too MUST connect to the same receptacle or plug strip. Any phone lines should be disconnected from the laptop. Make sure everything has three wire cords. The interface probably sends out line level, so you should use a low gain input of the amp and use very little gain as the interface probably has 20 or more Db output than a guitar.

You have a grounding problem ! You need to BOND (electrically connect) all the metal parts including the cases and shafts of the volume controls and switches. OFTEN the cavity with the controls are painted with a conductive paint such as Aquadag or NicklePrint which is then bonded to the barrel part of the jack you plug into. Note, while this helps the buzzing due to touching the metaal parts, it will not eliminate hum if you get your guitar pickups into a magnetic field from transformers, etc.

Make sure you have a ground prong on your power cord. Most input jacks nowadays are closed circuit. They have a switch built in that won't allow any sound without the cord plugged in. You may have a damaged jack that will give you a loud hiss, a loud hum or crackling depending on what volume your controls are set at.

If you are saying that you are plugging a guitar cord into an input on an amp without the guitar on the other end and you are getting a hum or buzz with the volume turned up ; that is normal. If you are getting the same results with a guitar plugged in it means the ground wire to your output jack on your guitar is broken. Check your cord with a volt ohm meter for continuity on the tip on one end to the tip on the other end. Do this for the sleeve on one end to the other. If you were getting the buzz without a cable it would mean that your input jack in your amp has a broken ground connection. Hope this helps.

the buzzing is indicative of an open ground connection, check the cord by substitution or with an ohm meter, if the cord is good look at the connections to the jack inside the amp ( im guessing you built the amp from a kit). Is this a solid state amplifier? Tube amps have lethal votages and should not be experimented on without knowledge of electronic safety. Also if there is more than one input to the amp try plugging the guitar into another one and see if its still the same.