Squealing from Helix

[joshn16]

I have a Helix LT that I plug into a Blackstar ID 100 V2 (a digital amp that I use for practicing at home). The Blackstar has an audio jack input that bypasses the amp and goes straight to the speaker, so I have the 1/4" phones converted to 1/8" and run into that.

I'm not sure when it started, maybe a few months ago, but there has been a constant, high pitch squealing coming from the speakers. The only thing that makes it go away is either completing unplugging the amp from the helix or unplugging the helix. It does not matter whether the helix is powered on or not, or what outlet either of them is plugged in to (I have tried plugging them into the same wall socket, same power strip, different sockets, extension cords to different parts of the house, you get the idea). I'm also sure it is not a cable problem, as I have tried many different cables, in addition to left or right 1/4" output from the helix, and going straight into the Blackstar 1/4" which runs through the amp. My cousin has a Pod HD, which when set up in the same fashion as the helix has no squealing at all. I also tried running the output into a mini portable everyday use speaker, and had no squealing there.

 

I'm rather new to guitar affects systems, and electric guitar in general I guess, so I'm not sure where to start or what the cause of the problem is. Any suggestions and feedback is much welcomed, thanks :)

[rd2rk]

Either or both using USB?

 

[HonestOpinion]

On 7/17/2020 at 6:05 PM, joshn16 said:

I have a Helix LT that I plug into a Blackstar ID 100 V2 (a digital amp that I use for practicing at home). The Blackstar has an audio jack input that bypasses the amp and goes straight to the speaker, so I have the 1/4" phones converted to 1/8" and run into that.

I'm not sure when it started, maybe a few months ago, but there has been a constant, high pitch squealing coming from the speakers. The only thing that makes it go away is either completing unplugging the amp from the helix or unplugging the helix. It does not matter whether the helix is powered on or not, or what outlet either of them is plugged in to (I have tried plugging them into the same wall socket, same power strip, different sockets, extension cords to different parts of the house, you get the idea). I'm also sure it is not a cable problem, as I have tried many different cables, in addition to left or right 1/4" output from the helix, and going straight into the Blackstar 1/4" which runs through the amp. My cousin has a Pod HD, which when set up in the same fashion as the helix has no squealing at all. I also tried running the output into a mini portable everyday use speaker, and had no squealing there.

 

I'm rather new to guitar affects systems, and electric guitar in general I guess, so I'm not sure where to start or what the cause of the problem is. Any suggestions and feedback is much welcomed, thanks :)

 

The first thing I would think was my signal was too hot but it sounds like there are other mitigating factors here. Here are a few questions that may or may not help narrow things down. Have you tried the ground lift button on the back of the LT?  Does this happen with a different guitar or with no guitar cord plugged into the LT? You mentioned that "unplugging the Helix" stops the squealing. Does that mean that just turning off the Helix while still plugged in does not stop the squealing. If so it almost sounds like something is picking up radio frequencies . 

 

Does the main volume knob on the LT control the 1/4 output you are using and if so does the squeal stop if you turn it down? Does the squealing happen on every preset?

 

It sounds like you are using the Blackstar's "MP3/Line In" connection. Are you doing that to feed it a stereo signal? Are you running in mono or stereo out of your LT? If your global settings 'Ins/Outs' --> '1/4" Outputs' is set to "Instrument", try setting it to "Line".  I believe MP3 and CD players usually provide a line level signal so that might be what that input circuit is expecting.

 

Last but certainly not least if you are using the "MP3/Line In" connection have you tried configuring it to be a loop per the section below from the Blackstar manual? That might make the input work better(?) than leaving it in its default "MP3/Line In" mode.  Appears the loop is mono if you go this route though.

 

"Mono Effects Loop Switching on the Effects Loop via the free Blackstar INSIDER software transforms the Emulated Output and MP3/Line Input sockets into ‘Preamp Out’ (for sending a signal to your external effects) and ‘Power Amp In’ (for returning the effected signal to your amp). This means that in addition to using the studio quality effects within your amp, you can place your own external effects and stomp boxes ‘in the loop’ for the best sonic performance. When the Effects Loop is activated, you may still use the USB audio interface as a line in/out."

[joshn16]

I've tried the ground lift, neither positions change the squeal, and it doesn't matter whether there is a guitar plugged in or not, or if the helix is on or not, it squeals whenever the helix is plugged in. It should make sense then that the volume knob and presets also do nothing to help, it is the same regardless.

 

I haven't tried configuring the MP3 input to be a loop, as INSIDER isn't supported on Mac OS Catalina, however I will try installing it on our Windows 10 PC and try that.

For at home practice mono output is fine, you can barely hear a difference between mono and stereo through the little amp :D

 

Thanks!

[rd2rk]

21 hours ago, rd2rk said:

Either or both using USB?

 

 

That's not a silly question. No one here can hear the "squealing". A USB grounding problem can cause a squealing noise. Unplug the Helix USB and your Blackstar USB and any other USB that's not essential to computer function. If it's still squealing, at least you've eliminated that possibility.

[HonestOpinion]

44 minutes ago, joshn16 said:

I've tried the ground lift, neither positions change the squeal, and it doesn't matter whether there is a guitar plugged in or not, or if the helix is on or not, it squeals whenever the helix is plugged in. It should make sense then that the volume knob and presets also do nothing to help, it is the same regardless.

 

I haven't tried configuring the MP3 input to be a loop, as INSIDER isn't supported on Mac OS Catalina, however I will try installing it on our Windows 10 PC and try that.

For at home practice mono output is fine, you can barely hear a difference between mono and stereo through the little amp :D

 

Thanks!

 

Good luck with this! Barring an actual defect or electronics failure with the Blackstar amp hopefully you will be able to get this working correctly. It is a bit concerning that it worked correctly and now it does not but that sort of thing is often due to an inadvertent change in settings on the LT(especially if you have been through multiple firmware updates) or other peripheral items failing or changing.  Please let us know if you get this figured out.

[datacommando]

On 7/17/2020 at 11:05 PM, joshn16 said:

My cousin has a Pod HD, which when set up in the same fashion as the helix has no squealing at all. I also tried running the output into a mini portable everyday use speaker, and had no squealing there.

Hi, 
 

A little clarification may help me understand this (old and feeble minded)

You mention your cousin and the POD HD, which doesn’t squeal.

Question: Do you mean when the POD HD is connected to your Blackstar?
(If yes, then it is possibly the cable and connection between the LT and Amp)
 

Also, when your Helix LT is connected to the portable speaker, there is no squeal - correct?

(if yes, I would suspect that this is more to do with the Blackstar than the LT.)

 

If you can get access to another amplifier, and/or powered speaker, then you could eliminate something from this scenario.