Hey guys. Got a quick question for anyone more experienced out there.
I've got a relatively low cost amp (a Stagg GA10) that I just want to use for practice - I'm a beginner. I've got some problems with it though, and I'd prefer to try and fix them at home due to a limited budget - I'm pretty good with a soldering iron.
The amp seems to work fine if I output my computer to it using the 1/8" stereo input jack on the front. If I plug in a guitar cable into the the 1/4" phono jack though, I get a low but noticeable static in the background (before the other end is even plugged into the guitar). Touching the grounding sleeve on the opposite end of the cable immediately kills the static. I thought maybe I had a bad cable, but I tried 2 other cables I had (all different brands) and get the same behavior. Also, if I plug the guitar (a Dean EVO XM) in, the background noise will generally persist unless I touch the strings at which time it goes away. Strangely enough either turning the volume all the way up on the guitar or the tone all the way up, the static will generally go away - volume all the way down on the guitar also takes away the static.
I was thinking that the input jack on the amp might just be bad, but figured I'd ask before starting to replace it.
Any advice is greatly appreciated.
Thanks.
Are you making sure that your 1/8" cable is indeed a stereo cable? I assume it is, if it is okay by itself.
So, is the 1/4" cable okay by itself - are you saying the problem comes from there? Does it happen without the computer hookup?
Like a bird on the wire,
like a drunk in a midnight choir
I have tried in my way to be free.
I've never tried both connectors in at the same time. The 1/8" plug is indeed stereo - I basically plugged it in as a test earlier and got no static, so the computer hookup seems fine.
I get static with just the 1/4" plug in (but again never tried it with both in). This static continues after I plug the guitar in but goes away if I touch the strings or the input jack's plate. It also tends to go away if either of the pot knobs is turned to it's furthest position in either direction - but in between settings it comes back.
If I plug in a guitar cable into the the 1/4" phono jack though, I get a low but noticeable static in the background (before the other end is even plugged into the guitar).
I would expect that. Any amp will do that.
It's using the open end of the cable as an antenna.
Also, if I plug the guitar (a Dean EVO XM) in, the background noise will generally persist unless I touch the strings at which time it goes away.
It may be an issue with the guitar. Often noises that go away when you touch the strings are related to grounding.
Usually a lack of grounding of the strings thru the bridge.
Do you have a multimeter?
Is there continuity between the sleeve of the 1/4" jack on the guitar and the metal of the bridge (or the strings themselves)?
I wrapped a newspaper ’round my head
So I looked like I was deep
Good advice so far. But sorry, I don't think I can diagnose this one from a distance, even after studying the amp and reading reviews of this model. You could have a faulty one - I don't think it is limited solely to the jack, which is part of the circuit board anyhow, tacked to it pretty good, and not easily removable.
Try some simple tests as suggested on your guitar, or take your guitar to another amp and see what happens, although I think I get the point, your complaint was with the amp alone. However it does sound as if there is a grounding issue in the guitar as well. But again, if the amp is not fully grounded (it may be the circuit in your house, or the power outlet, or the amp's cord) that problem could be spreading to your guitar and making it seem strange, when it's not. I hope that is encouraging.
Like a bird on the wire,
like a drunk in a midnight choir
I have tried in my way to be free.
