davebode

I am not sure there is a fix for this. It's not a bug, it's a feature. This is how the Helix amp modeling works. There is some fundamental issue that you and I are hearing that has to do with the way the high frequency noise is attenuated. It sounds ok at full signal, but as the signal decays it cuts off abruptly. The Helix is still worth a chunk of change. Get rid of it and get on the waitlist for the FM9. Or get a ToneX Pedal and the HX Stomp. Use the ToneX for all the amp and cab stuff and use the HX for delays, mod, EQ, and reverb. MIDI from the HX Stomp to the ToneX for amp switching and add an expression pedal. You will lose XLR out, but that's about the best setup if you want to stay in the Line 6 family.

Update - After several hours of manipulating all the amp settings in the Helix I returned it. There was no combination of settings that got rid of that brittle sound of the distortion on the Helix and HX Stomp. I like the Helix and it can produce many excellent sounds, especially fully clipped (high distortion) and clean amp sounds. However the sound of the high frequency distortion cutting in and out, rather than smoothly fading as the note decays, was a deal breaker. Once you hear it, you cannot unhear it. And that stanky distortion sound colors the delays and verbs and it was driving me nuts! I bought an Fractal Audio FM3 to see how deep the rabbit hole truly goes. The FM3 is brilliant and the sound of the distortion/overdrive/breakup is incredibly good. The way that the distortion/overdrive works is very smooth. If you know someone who has an Axe FX III, FM9, or FM3 go listen to it and poke around with the amps. No Helix hate here. It's a great unit. The amp models are not for me. The modulation, delays, filters, and verbs are outstanding. I considered keeping the HX Stomp to use as a delay and reverb box with my Headrush MX5. It seemed like too much trouble without the use of a Morningstar MIDI controller and Morningstar has no products to sell. Plus, when I added up the cost of everything (MX5, Cali76 Stacked [because nothing really beats that compressor], HX Stomp, and Morningstar controller) it was more than a FM9. So I returned the FM3 (ate the shipping both ways) and jumped on the waitlist for the FM9. Happy trails Helix Crew!

I loudness matched all of the items in Reaper to -17 LUFS and bypassed all my master track effects. I think the uneven quality you are describing is what another might call dynamics. It's odd that you would get readings like that when the first example, the MX5, has the lowest True Peak measurement. That MX5 clip also has the lowest LRA measurement, which is loudness range. Those measurements are in mono. The stereo loudness calculations are exactly 3dB higher. I appreciate you listening to them and commenting!

I wasn't trying to match them. I was trying to evaluate the difference in the distortion from all three. I had been going back and forth from my Headrush to the Helix but I know a lot of folks get hung up on how a modeler might compare to a real amp. So I threw a real amp in there as well. The pad was not engaged on the Helix. It's a fairly strong guitar signal. When I check the input levels on the Headrush my Solar comes it at -6dB if I am smashing chords. I like the Helix a good deal of processing power to run just about anything I'd need to do. But I am not sure I can keep it because this amp distortion is driving me nuts. Once you hear it, you can't unhear it. Thanks for replying.

I just bought a Helix LT as a replacement for my HR MX5. When comparing amp models with the same IR I am noticing that the Helix has this odd behavior on any overdriven/distorted amp. As the notes decay there is a chattering that happens on the upper harmonics. In other words the higher frequency noise doesn't fade away smoothly as the note does. Instead, it kind of chatters like a gate or noise filter when the input is right at the threshold. I also compared this to a tube amp and tweaked the settings to sound pretty close. Check out the demo. The examples are Headrush AC HI BOOST (Celestion IR), Helix A30 Fawn Brt (Celestion IR), and Peavey Bravo 112 recorded with a Beta57A. I didn't fuss with the positioning of the mic on the Peavey. I would reckon they sound pretty similar. The thing that is bugging me is the distortion decay on the Helix. It comes on and decays rather abruptly and I think I know why. Going back and forth between the Headrush and the Helix and then the Peavey I noticed something. The Headrush and Peavey have a background hiss when the preamp gain is up and the Helix doesn't. Is this some kind of Magic? No. I think what is happening is that there is some kind of noise filter that is processing the upper harmonics/distortion noise separately from a lower overdriven amp sound on the Helix. As the input envelop starts to decay, it starts increasing the noise reduction/gate threshold and that's why it chatters. It does the same thing on the attacks of notes to some degree. The decay of the upper harmonics/noise on the Peavey is a little smoother and I don't hear them cut off abruptly like the Helix does. The Headrush also has a smooth decay of the harmonics. To me the Headrush is a bit smoother than this particular Peavey amp, but it's more preferable than the Helix at this point. If there is some magic setting I am missing, do let me know. I have experimented with the bias, bias x, ripple, hum, and sag. This chattering distortion doesn't really change. Right not the bias is at 9. I have tried a bunch of different amps. Some exhibit this chattering behavior more than others. Example order - Headrush - Helix - Peavey Helix VS Headrush vs Peavey.mp3