Problem running FX loop #4 - Helix Rack

[dbdbdb]

Hey Guys ...... Need help with a problem I'm experiencing.

 

 

I'm running four pedals through FX-loop 1-4. But I'm getting weird effects (diminished sound, plus nasal sound) when I enable the 4th FX-loop. When the fx-loop #1 through #3 is enabled and the fourth bypassed, I don't hear any degradation in sound or artifacts. But once I enable the fourth fx-loop with the polara, I lose volume and the nasal sound starts.

Its not the cables and its not the pedals, because I've switched\swapped all the cables and efx and the problem only occurs when the fourth fx-loop is enabled.

fx-loop #1 - Luxe \ Nautila
fx-loop #2 - Ventura Vibe
fx-loop #3 - Obscura
fx-loop #4 - Polara

Cabling: Evidence Audio Monorail cable with SIS Plugs (All verified with multimeter for integrity)


Here's the patch:

AUX -- noise gate -- parametric EQ -- LA studio comp. -- FX#1 -- FX#2 -- FX#3 -- (Output path 2A)
           (Input none) -- IR -- LA studio comp. -- Room Reverb -- (Merge Mixer) ------ (Output)
                               -- IR -- LA studio comp. ---- FX#4 ------- ( up to Merge Mixer)

 

Questions:

Is this issue related to running the fourth fx-loop along with #1-#3 or is this problem related to helix CPU usage ?
is there possibly a problem with the fourth FX-Loop ?
 

Thanks in advance

[dbdbdb]

I can also confirm that this problem occurs with the Helix floor model as well.

 

I patched the pedals mentioned above with different cables and the same issue\problem occurs with the fourth FX-loop.

 

Regards

[Verne-Bunsen]

If you move FX Loop 4 from the parallel path up to either before the split or after the merge, does the problem resolve? The factor that your troubleshooting has not addressed is that only Loop 4 is set in parallel to another signal path. I suspect that if you move one of the other loops down there, then it would suddenly be the troublesome one. I have experienced "phasing" issues when running a pedal in an FX Loop on a parallel path, which I attribute to half of the signal being subject the small latency introduced by the extra cabling and the circuitry of the pedal itself while the other half of the signal is not.

[dbdbdb]

If you move FX Loop 4 from the parallel path up to either before the split or after the merge, does the problem resolve? The factor that your troubleshooting has not addressed is that only Loop 4 is set in parallel to another signal path. I suspect that if you move one of the other loops down there, then it would suddenly be the troublesome one. I have experienced "phasing" issues when running a pedal in an FX Loop on a parallel path, which I attribute to half of the signal being subject the small latency introduced by the extra cabling and the circuitry of the pedal itself while the other half of the signal is not.

 

Ahhhhh .... Thank you for the solution.

 

I conducted several tests and found that splitting the signal on either A or B and using an fx-loop on either split path will create this problem.

 

Thanks for your help!!!!

 

Now I have to redesign that patch .........

[Verne-Bunsen]

Glad I could help! Bummer to have to re-design the patch, but at least you can know what you’re trying to fix ðŸ‘

[rzumwalt]

I can add on to this topic to say that a similar problem occurs when the Strymon Big Sky is in an FX loop on a parallel path. Big Sky is a digital reverb pedal like the Polara. It sounds to me like comb filtering or phasing due to some very slight delay in the parallel path introduced by the loop and effect pedal, as Verne-Bunson also theorized above. I think this is going to be a problem for any quality digital reverb.

I'll explain:

I've heard from good authority on this forum that the small delays caused by the D/A and A/D converters on the FX loops is compensated for by Helix's programming.  My theory is that two of the qualities of a pedal like Strymon Big Sky combine to make this happen: (1) it is digital, and therefore unavoidably introduces a delay to the signal, and (2) includes a dry-through signal which is an exact replica of the waveform on the parallel path, except very slightly delayed. I think one of the things that makes the Strymon so good is that dry-through component, and I'm willing to bet Polara does the same based on dbdbdb's experience.

[Verne-Bunsen]

I think this is going to be a problem for any quality digital reverb.

 

 

Interesting point. When I encountered it it was also with a reverb pedal, a Malekko Spring Chicken. Can't say I've tried it with anything else...

[phil_m]

I can add on to this topic to say that a similar problem occurs when the Strymon Big Sky is in an FX loop on a parallel path. Big Sky is a digital reverb pedal like the Polara. It sounds to me like comb filtering or phasing due to some very slight delay in the parallel path introduced by the loop and effect pedal, as Verne-Bunson also theorized above. I think this is going to be a problem for any quality digital reverb.

I'll explain:

I've heard from good authority on this forum that the small delays caused by the D/A and A/D converters on the FX loops is compensated for by Helix's programming.  My theory is that two of the qualities of a pedal like Strymon Big Sky combine to make this happen: (1) it is digital, and therefore unavoidably introduces a delay to the signal, and (2) includes a dry-through signal which is an exact replica of the waveform on the parallel path, except very slightly delayed. I think one of the things that makes the Strymon so good is that dry-through component, and I'm willing to bet Polara does the same based on dbdbdb's experience.

 

You would need to kill the dry signal going through the parallel effect in order for it to work in a parallel path. The BigSky has a Dry Kill global setting. Most other reverb pedals don't.