Amp/Pedalboard Suddenly Squealing - Help...

[Junk Yard Dog]

I've experienced this before to a degree. Rig sounds great, no problems, and then boom, suddenly something's micro-phonic, causing that high-pitched squeal. It only happens when I add my boost, which is a TC Spark and it gets worse when I use my wah pedal--and it happened with both wah's, Crybaby 535q and Budda.

I've not changed my amp settings or pedal settings at all. I play mid-gain (1:00) on my modded Marshall amp (4 gain stages, so I"m not playing super high gain).

The ONLY thing that I changed last night was I moved around the patch cables. None of the pedals changed power inserts on my Pedal Power 2.

I tried different guitars, cables, etc. and it was still happening. Could this be a preamp tube that's outta sorts?

I seemed to be "on the verge" when I turned up the gain on my amp. So I"m wondering if it could be one of the patch cables or maybe one of my preamp tubes is going out?

Look forward to suggestions on how to trouble shoot.

 

[8len8]

How are you powering your board? Wahs don’t like to be near power supplies (their inductors pick up EMI).

 

[Junk Yard Dog]

How are you powering your board? Wahs don’t like to be near power supplies (their inductors pick up EMI).

I'm powering it directly into a 9volt connect into the Voodoo Pedal Power then from there direct into the wall outlet. It was doing it at our band room and now at my house.

UPDATE: I just tried a different amp, my Splawn Pro Stock, and it's not doing it to the degree it was on my Modded Marshall. I'm leaning toward it may be the amp, HOWEVER, I'm still looking for suggestions on how to trouble shoot.

Thanks!

 

[LP Freak]

Try swapping out V1

 

[8len8]

The Pedal Power is a switching power supply that generates EMI. Try moving the wah away from it.

 

[Junk Yard Dog]

The Pedal Power is a switching power supply that generates EMI. Try moving the wah away from it.

OK, I can try this. But why would it all of the sudden start doing this? I've had this same board and pedal order for 6 years and I feel like its only just happened.

When you say move the way you mean take it off being powered by the Voodoo PP and power it separately or something?

 

[8len8]

No, physically move it away from the PP2+. EMI travels through the air.

 

[Riggins1966]

No, physically move it away from the PP2+. EMI travels through the air.

this, if you've recently re-organized your pedals. Found this out myself when I switched to a mini wah. Howled and buzzed like crazy because I didn't realize I placed it right over my PS (voodoo ISO 5).

moved to the PS to the other end of the board and now there's zero noise.

 

[Junk Yard Dog]

No, physically move it away from the PP2+. EMI travels through the air.

this, if you've recently re-organized your pedals. Found this out myself when I switched to a mini wah. Howled and buzzed like crazy because I didn't realize I placed it right over my PS (voodoo ISO 5).

moved to the PS to the other end of the board and now there's zero noise.

Thanks, man. ...I did not move any pedals, just the cables. My frustration with this is that I've had the same pedal setup on my board for years and it never did this. All pedals have been in the same position since 2012.

My pedalboard is a PT-2, so it's not super large, but the PP2 is sitting in the very middle of the board. I'll see if this helps. BTW, it's not the hum issue described in other threads. It's when my TC Spark is engaged on top of the OD of the amp and then I use the wah and that makes the high-pitch squeal worse. It's like a microphonic feedback.

Again, why all of the sudden after years is this happening?

Thanks for the help and I'll report back.

 

[Riggins1966]

No, physically move it away from the PP2+. EMI travels through the air.

this, if you've recently re-organized your pedals. Found this out myself when I switched to a mini wah. Howled and buzzed like crazy because I didn't realize I placed it right over my PS (voodoo ISO 5).

moved to the PS to the other end of the board and now there's zero noise.

Thanks, man. ...I did not move any pedals, just the cables. My frustration with this is that I've had the same pedal setup on my board for years and it never did this. All pedals have been in the same position since 2012.

My pedalboard is a PT-2, so it's not super large, but the PP2 is sitting in the very middle of the board. I'll see if this helps. BTW, it's not the hum issue described in other threads. It's when my TC Spark is engaged on top of the OD of the amp and then I use the wah and that makes the high-pitch squeal worse. It's like a microphonic feedback.

Again, why all of the sudden after years is this happening?

Thanks for the help and I'll report back.

sounds like you may have a bad tube. Since the problem only manifests when the boost kicks on, I'm thinking the preamp tube in that position may be going bad. Did you do a tap test (pencil with eraser, or similar) on those tubes to see if there are any bad ones?

 

[Junk Yard Dog]

sounds like you may have a bad tube. Since the problem only manifests when the boost kicks on, I'm thinking the preamp tube in that position may be going bad. Did you do a tap test (pencil with eraser, or similar) on those tubes to see if there are any bad ones?

Yup, I'm going to try that as well; I've got a tone of good 12ax7's laying around. I'll do both, to be on the safe side. ...I don't have the drill bit to get through the metal on the PT2, so can someone recommend what I need for that?

Thanks!

 

[Junk Yard Dog]

Well, I've experiemented with just plugging the guitars straight to two amps. 4 different guitars and two modded Marshall amps (4 gain stages each) and they were BOTH squealing (high pitched constant 'waaaaaaaaah') when closer to the amp. Once I lowered volume and gain, the squeals went away. But again: I don't recall they ever doing this before.

Some guitars did it more than others. 3 of the 4 guitars have Duncan C8 and one has a regular SH5 (ceramic). The SH5 squealed the most, and at first I thought the pickup wasn't grounded. But when the other pickups started to do it, I figured it wasn't just the pickups.

I have a LOT of 12AX7's lying around and I don't put high gain tubes in V1, or what I would consider high gain. I either have 12AX7B's or Tun-Sols.

I tried three different 18' Mogami gold cables and all three resulted in the same. I'm wondering if it's a speaker cable, lights in my apartment, etc. But it was doing it on one of the amps in my jam room.

As you can imagine, it's quite frustrating and a little defeating. I don't dime the gain in these amps so I can't help but think something is up.

Any other ideas?? ...So it's not the pedalboard and wah. I'm leaning toward too much gain. I have a noise suppressor. I guess it doesn't matter because it's not happening while playing songs live so much and I always throttle guitar volume to zero in between songs.

I have a gig this weekend and I'm kind of nervous.