Jump to content

4 cable method making hum noise to amp


mikeebruno
 Share

Recommended Posts

Can someone help with my noisy setup ? 
i have a helix going 4 CM with a DSL 100 h. 
it is making a big hum specifically through lead channel. ( drive from marshals own distortions)
Gtr going to helix Guitar in. 
out from send 1 to amp guitar input 

( at that stage the hum is made)

out from amp loop send to helix return 1

out from helix 1/4 output to amp return. 
 

Then I plug my gtr straight to amp guitar input and leave the effect loop in and out with helix ,and it’s fine ! 
So the hum is at the stage before amp input in the helix. 
Note that no block at all is in that helix patch. Totally blank patch. 
how come ? 
how could I fix this? 
thanks

Link to comment
Share on other sites

All of the audio devices should be running from the same electrical source (to eliminate ground loops).

The FX loop does add a small bit of noise. It's NBD with my Tweaker, but that's not a high gain amp.

You could try lowering the SEND level (might have to increase the Output level of prior FX), or use a "hum buster" type of device between the SEND and Amp Input.

That worked for me (the hum buster) with an Engl that I had.

Link to comment
Share on other sites

In addition to running from the same source as rd2rk suggested, I also use a transformer based AVR (Automatic Voltage Regulator) on the input power for my entire rig. Ground loops are something I dealt with before I used an AVR...1985 maybe?...I have toured globally with this approach...Hum eliminators are pretty rare for me but I always have at least one...I have had some rack rigs in the past where I had some internal ground loops, but those are usually solved with a couple of signal shield lifts to normalize the rig signal ground path...Additionally in rack rigs, all but one component electrical ground are lifted because the rack rails...I always use a "hum eliminator" but that is just a direct box connecting to other systems that are not on my source power...signal isolation...

 

I used a Furman AR-15 for years...These days a Tripp Lite LCR1200 is plenty and just a good as the Furman but quite a bit less $$....Power Conditioners are NOT AVRs.

  • Upvote 1
Link to comment
Share on other sites

On 10/10/2021 at 11:59 AM, bobpick said:

For me the fix was to set my send block to line level. The hum instantly disappeared. It's not optimal because my Helix send is going to the amps input. I adjusted level to compensate.

You can also adjust the signal strength of your send/return. 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...