I'm new to the forum, new to guitars and amps and I don't even play but my son does and he's been playing for 3 years and we seem to have a feedback problem.

Here's some background We've just gotten a Marshall MG100HDFX head and I'm putting together two single cabinets with some Peavey 15" Black Widow speakers I've picked up. He has a Dean 7 string with dual humbuckers, a Univox Les Paul knockoff and a Jay Turser 5 string bass.

He used to use a Peavey Studio Pro 50 and the feedback issue was always there a little bit but not nearly as bad as it seems to be now. When using either of his electric guitars in the Marshall while playing clean everything seems to be fine (no feedback issues). While in distortion we have a big problem. You can just set his guitar down and the noise will just start to build all on its own with nobody near it, the strings start to vibrate on their own and you can press lightly on the string and the noise will stop and then slowly start again, it could be the same string or another one.

Is this feedback ? How do I fix this ?

I've potted the pickups in his Univox to no avail, re-routed his grounding a couple of times again in the Univox (I don't want to mess with his 7 string until I have a fix if possible), bought a $40 patch cord, searched the internet, asked a couple of friends .....

I really don't want to have pay anyone to fix this for us (if we really do have a problem). My son is 14 and really keen on learnig as much as he can so he can be his own techy. I'd like to help but I've run out of ideas, any help would be greatly appreciated.

I hope I didn't ramble too much for my first post.

bill2455

Hey Bill,

Welcome to the forums.....

How close is your son playing from the marshall?
When you set the guitar down are you turning the volume down?
If not any guitar will do feedback like your talking about.

If you have the volume cranked and playing in a small room this will happen as the sound waves are just bouncing like crazy....

Does the feedback start with a deep rouring sound???

Let us know

Thanks
Brian

How are the tubes,
Are they microphonic


Do you have the reverb cranked

HI guys;

Thanks for the replys.

We are in a small room right now, maybe we'll try the livingroom tonight. The feedback starts as a small sound and continually builds. His amp is a new solidstate from Marshall, and no effects enabled. His friends Ibanez is fairly quiet in the same room on the same gear.

Will shielding maybe help ?

It could be cheap pickups????

Does this feedback happen while your playing or when you stop?
Or Both?

It happens both when he's playing and not playing, now that I've listening for it. It could be the pickups, I've had them out of both guitars and theres no brand name on either set. Maybe I should try potting the 7 string pickups and see what happens.

Does anyone know whether shielding might help ?

Thanx

Sounds like grounding Problem. Maybe a ground loop!

Brian

Sounds to me like too much distortion, too much volume and too close to the amp.
If he moves away from the amop and turns the distortion and/or volume down, it will be ok