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farrellk

Fizz & splat when using Helix as stomp box in front of guitar amp

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I'm trying to migrate to the Helix from my HD500X, and am not able to get rid of the overtly fizzy top end when inserting a distortion effect.  I've seen mention of fizzy high-end in some of these threads, but I've not found a solution that mitigates the issue when using the Helix as a front-end stomp-box-type pedal feeding an outboard guitar amp.

 

To simplify things on the Helix, I've got a chain with ONE module - the Valve Driver Distortion. On my HD500X I used a Tube Drive. Both of those effects are intended to mirror the Chandler Tube Drive. I'm taking a mono 1/4" Out from the Helix, and sending that to the front of my '65 Fender Deluxe Reissue amp. I do the same with the HD500X, and swap the output of each unit feeding the front of the amp.

 

- On the HD500X, I've got the Input Impedance set to AUTO, and have set the Helix Input to the same.

- On the HD500X, I've got the Guitar Pad on NORMAL, and have set the Helix Guitar Pad to OFF.

- On the HD500X, I've got the 1/4" Out set to AMP, and have set the Helix 1/4" Out to INSTRUMENT.

 

That is it. Squeaky clean simple - or so I would think.  Distortion settings on the 2 units are the same (though, for some reason the HD500X has Midrange control for its Tube Drive (set at 50%).  Drive, Bass, Treble and Output are set identical between the HD500X and the Helix.

 

There is an overt amount of top end fizz and splat coming from the Helix when using a Distortion effect.  Clean sounds seem to be OK.  I've tried different Distortion effects, and all produce the same high end characteristic. It's like plugging an MXR Distortion+ directly into a mixing console.  I'm at a loss in determining how to mitigate the issue.

 

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I wouldn't necessarily expect the HD500 and Helix models to sound the same at the same settings, they're different models and the numbers might not relate that closely. Helix also has different I/O and might produce a wider frequency response.

 

I find the Valve Drive distortion in Helix to be quite bright, and useful as a first stage gain boost. When using it for distortion, expect to have to turn the treble down quite a bit when going into the front of an amp. You've probably set your amp for your desired clean sound and that is probably actually quite bright. You'll need to compensate for that with the tone controls on the distortion effect to give more of a mid focus, cutting both highs and lows. Try the Fulton OCD and ProCo Rat models, these are actually quite musical in Helix.

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Interesting, amsdenj.  I hadn't thought of it in that regard - mainly because I've been conditioned that L6's effects (e.g., the Chandler Tube Driver) had been so consistent as they introduce new products. From my M13 to my HD500, to my HD500X, effects had been quite consistent.  I definitely jumped to conclusion and assumed that it would be that way when migrating to the Helix.

 

I will explore doing just as you suggest, and look at the modeled effects in the Helix as completely new animals that are different from what I'm used to. Thank-you for the perspective.


I wouldn't necessarily expect the HD500 and Helix models to sound the same at the same settings, they're different models and the numbers might not relate that closely. Helix also has different I/O and might produce a wider frequency response.

 

I find the Valve Drive distortion in Helix to be quite bright, and useful as a first stage gain boost. When using it for distortion, expect to have to turn the treble down quite a bit when going into the front of an amp. You've probably set your amp for your desired clean sound and that is probably actually quite bright. You'll need to compensate for that with the tone controls on the distortion effect to give more of a mid focus, cutting both highs and lows. Try the Fulton OCD and ProCo Rat models, these are actually quite musical in Helix.

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I'm trying to migrate to the Helix from my HD500X, and am not able to get rid of the overtly fizzy top end when inserting a distortion effect.  I've seen mention of fizzy high-end in some of these threads, but I've not found a solution that mitigates the issue when using the Helix as a front-end stomp-box-type pedal feeding an outboard guitar amp.

 

To simplify things on the Helix, I've got a chain with ONE module - the Valve Driver Distortion. On my HD500X I used a Tube Drive. Both of those effects are intended to mirror the Chandler Tube Drive. I'm taking a mono 1/4" Out from the Helix, and sending that to the front of my '65 Fender Deluxe Reissue amp. I do the same with the HD500X, and swap the output of each unit feeding the front of the amp.

 

- On the HD500X, I've got the Input Impedance set to AUTO, and have set the Helix Input to the same.

- On the HD500X, I've got the Guitar Pad on NORMAL, and have set the Helix Guitar Pad to OFF.

- On the HD500X, I've got the 1/4" Out set to AMP, and have set the Helix 1/4" Out to INSTRUMENT.

 

That is it. Squeaky clean simple - or so I would think.  Distortion settings on the 2 units are the same (though, for some reason the HD500X has Midrange control for its Tube Drive (set at 50%).  Drive, Bass, Treble and Output are set identical between the HD500X and the Helix.

 

There is an overt amount of top end fizz and splat coming from the Helix when using a Distortion effect.  Clean sounds seem to be OK.  I've tried different Distortion effects, and all produce the same high end characteristic. It's like plugging an MXR Distortion+ directly into a mixing console.  I'm at a loss in determining how to mitigate the issue.

 

I am hearing the fizz too, particularly when the distortions are cranked up. Have not done enough tweaking on all my presets yet but it usually requires finding the offending frequencies with a parametric or graphic EQ. and dialing them out. The "fizz" I am hearing is what gives MFX that "digital" sound, Setting up a low pass filter helps but does not totally get rid of it unless you cut the highs more dramatically then I want to.  There are some other offending frequencies elsewhere that I cut out more surgically with EQ. I want my sound to be as close as possible to an analog tube amp and pedals (at least for my meat and potatoes, go to sounds). That fizz is what gives it away.  Was hoping that would be completely absent in the Helix and it is absent from many sounds but it looks like it needs to be dialed out on some effects and settings. Not unusual I guess.

 

I am thinking 3khz may be one area to keep and eye on. Saw an interesting quote in the documentation for Ownhammer's demo IRs. It is supposed to apply to his IRs but it might be worth trying with the Helix cabs. Not sure if it will apply as this seems like a lower range than where fizz would be present but perhaps not as he sets the "Q" on the parametric quite wide. I am going to play around with it. Here is the quote from the Ownhammer documentation.

 

"With the files contained in this library there is a very quick, simple step that can be taken to duplicate the sound of a guitar tube power amp with the Presence and Depth set to 0. To replicate this sound, following the cabinet IR loader add an EQ with a parametric bell curve set to -3 dB at 400 Hz. Adjust the Q/bandwidth to roughly where the edges of the curve start to make the initial cut around 100 Hz on the low side and 2 kHz on the high side. If necessary, adjust the Q/bandwidth to taste from here to best suit your sound source and tonal preference."

 

Any of you audio engineers out there know exactly where the "fizz" lives?

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In the topic questions about pre and power amp models??? It's suggested that at tube preamp inserted into the signal helps round off the digital edges. Thinking of giving that a shot. Definitely hearing this fizz you speak of, driving me nutz!

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In the topic questions about pre and power amp models??? It's suggested that at tube preamp inserted into the signal helps round off the digital edges. Thinking of giving that a shot. Definitely hearing this fizz you speak of, driving me nutz!

 

I know adding the ART pre or other similar schemes to get a tube in the signal chain after the Helix are working solutions but I am stubbornly clinging to the belief that I can EQ the nasty frequencies out just using the Helix. Although adding another device is a perfectly legitimate and simple solution, I feel like having to add additional processing and devices to get the Helix to sound natural is conceding defeat and I am not there yet.  And the Helix does sound natural on many settings, but it is not totally consistent, the ghosts of crappy digital sound still do show up here and there. I do wish there was a selection in the EQ section entitled "Fizz & Digital Crud Filter" that already had all the offending frequencies dialed out. I am not sure if that is possible as I don't know if the fizz is caused by the interaction of the Helix with a huge spectrum of possible external equipment, leaving no way to anticipate where the cuts should be. If it is impossible to anticipate where the fizz will be, ideally I suppose I would be able to plug in a reference mic that listened to the sound being produced and responded by using an L6 designed algorithm and filters to automatically tweak it to analog warmth. Until then, I intend to become a wizard with EQ.

 

I don't get the fizz when I go through a tube amp and analog pedals and I would really like to not have to hear it on a high end MFX. At least many sounds/settings leave me exclaiming "this sounds really close or even indistinguishable from a real tube amp", but consistent analog warmth still appears to require some tweaking. A little disappointing I must admit but probably producing a device that has the option of full frequency response may always require specific filtering to emulate analog warmth. Even when the Helix delivers perfect tone the device you play it through might emphasize an unpleasant frequency. It would be great to see it made it a little simpler for the end user with some concrete recommendations on what to tweak, an EQ "analog" filter selection, or as mentioned above, with reference mic technology and automated filtering. 

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