Brand new squealing issue with my Effect Gizmo to XTC.

[DRC]

Even though I will probably just call Ron on this one tomorrow afternoon, I thought it might be helpful to post this for Troubleshooting purposes. Just in case anyone has, had, or will have this problem.

This never happened before but I also just started running this rig at stage volume. I run a pair of heads using the isolated loops. I have never run into a ground loop yet and running to both the lo and hi inputs on both amps has never been a problem. But the other day I started to get this rig ready for live use. I am using a Dr.Z RX and a Bogner XTC. I had no problem what so ever cranking the Z. But for some reason the XTC starts squeaing like crazy on either hi or lo inputs.

So I thought it might be the order (not that it should matter because the loops are isolated right?) and began switching the input order. Nothing. Then I thought it might be a problem with having the lo and hi patched (not that I ever run them at the same time). Nothing. Then I start to think I have a microphonic tube. I just had this amp retubed and biased not that long ago and I haven't run it that hot in that time. So I pull the XTC from the RJM and run straight to it. Guitar > Cable > XTC........ No squealing. Sounds fine. I crank it a bit louder. Fine.

I'm just wondering if anyone has had this occur. I find it hard to believe it's the Effects Gizmo because the Dr.Z runs like a champ in both lo and hi through it's respective loops, but my XTC squeals in the loop but not direct from the guitar.

Any answers??????

 

[rjmmusic]

I've heard about stuff like this happening in the past. Have you tried using the buffer (or not using it if you were using it)?

 

[DRC]

I've heard about stuff like this happening in the past. Have you tried using the buffer (or not using it if you were using it)?

I just hooked up the buffer at the start of the chain. It worked. Just for the troubleshooting purposes of the forum, what do you think was the problem Ron?

Even though I'm not crazy about running the buffer in front of boost pedals and I liked the natural tone, signal loss and all, I'm pretty sure the tonal difference will be unnoticeable in a full band setting. Oh yeah... and the lack of squealing is kinda nice too.

Thanks for the help.

 

[rjmmusic]

I remember hearing about this with a CAE preamp. There's something going on with the high impedance of the guitar's signal - it interacts with the high gain of the amp. I don't remember all the details - I'll have to look them up. The important part is that the buffer greatly lowers the signal's impedance and keeps the problem from occurring.

You could use a couple of jumper cables to connect the buffer between the pedals and the amp's input so the pedals aren't affected by the buffer. It should still fix the squealing problem...