Helix Lt noise when Channel switching DSL 2000 head

[Broncos]

Good day folks.

 

I Finally upgraded to a Helix LT from (HD500X).

It is a mind blowing incredible pedal.

 

I do have to sort out an issue that me and a friend, whom both have the same (Older) Marshall amp

and same Helix pedal.

 

We both are using this pedal with the 4CM and using a modeled clean tone.

Now that we have the Helix and the ability to use snapshot mode we also want to utilize the

clean channel of the Marshall by changing amp channel with the helix using the EXP pedal 2 jack.

 

It works no problem changing the Channels but when plugging in the cable you instantly get a loud hum.

 

We tried everything and googled it extensively. As far as we can tell it is also a problem with both the Helix and the (Axe FX

units) with older amps. We tried a new DSL combo, it does not hum when using the Helix to switch channels.

 

Talking to my amp tech he needs to meter the Helix jack for continuity and he thinks its either a ground loop or something affecting the

switching matrix in the Head. Each jack on the DSL is a standard tip to sleeve short. But it is referenced to the chassis.

 

When he comes into town this weekend he is going to trouble shoot it for me.

 

I'm just curious if anyone else is having this issue on older amps? Has anyone had an amp tech fix the humming issue?

 

Any help or incite will be greatly appreciated.

 

Cheers

Rick

 

 

 

 

 

 

[Schmalle]

 

[Broncos]

Im not having a problem with the 4 cable method.

(mine is set to line level)

 

This is a external amp-channel changing issue using the Expression pedal 2 jack to

switch channels on my Marshall. The Loud humming only happens when plugging the

cable into the amp controller jack, using a regular guitar cable or a TRS cable.

 

This problem happens without the 4 cable method hook up as well.

[Schmalle]

On 2/3/2024 at 1:17 AM, Broncos said:

The Loud humming only happens when plugging the cable into the amp controller jack, using a regular guitar cable or a TRS cable.

That's a ground loop issue. You need an isolated switcher, something like the Voodoo Lab Control Switcher.

 

There have been some DIY versions of relay based switcher devices presented in this forum that use Helix's amp switching out for that (instead of MIDI).

 

 

 

[PerS]

Hi

 

This topic was "reopened" in December, might be a solution if you like to build things yourself... :-)  

 

The second solution will take care of the ground loop problem. But notice that it is built in a plastic box. If you build it in a metallic box you have to isolate the connectors from chassi, preferably on the relay side, from the ground. Or, use a three-pin connector (on the relay-side), eg a XLR, and ground will be on one of the pin's.  

 

Assumes one or two relay contacts can do the job. Slightly different depending on how the logic looks depending on the amplifier. May mean some form of supplementary logic is required in addition to the relay contacts. However, it is a good starting point to break the ground loop.

 

Oh, and if you just need one switch you just build half of the schematic... :-)

 

//Per

 

 

[Broncos]

On 2/3/2024 at 6:56 AM, Schmalle said:

That's a ground loop issue. You need an isolated switcher, something like the Voodoo Lab Control Switcher.

 

There have been some DIY versions of relay based switcher devices presented in this forum that use Helix's amp switching out for that (instead of MIDI).

 

 

 

The Switch that came with the amp works fine without causing the added hum.

Was hoping to switch the channels of the amp using the Helix to do it

using snapshots so i can simultaneously change the channel with specific FX

seamlessly. For live playing

 

Cheers

 

 

[Schmalle]

On 2/8/2024 at 12:48 AM, Broncos said:

The Switch that came with the amp works fine without causing the added hum.

Was hoping to switch the channels of the amp using the Helix to do it

using snapshots so i can simultaneously change the channel with specific FX

seamlessly. For live playing

 

Cheers

I understand that. There are solutions to it - see above. If I had that problem I'd search on the used marked for a Nobels MS-4 which works via MIDI. Or build a relay switching box.

[Broncos]

Hey Everyone, My amp guy finished modding my JCM800, its tone is unbelievable!!

So i showed him the issue with the DSL2000.

So he said the exact same thing about using a relay box he will build for me that will use

an adapter so i wont need to switch out batteries.

 

As soon as he checked the grounding on all my 4CM jacks on the Helix, while they

were plugged in the pedal, he knew exactly what Helix should have done.

I dont remember all the terminology, but he said the relay box will work for both my Marshall

Heads and he will build me two so i don't have to tote it around to both my band practice places.

 

thanks for all the Excellent advice and knowledge.

 

Greatly appreciated!

 

cheers

Rick