Line 6 Helix - All Tremolo Modes Examined

Line 6 Helix

Typically when you get a MultiFX unit, you tend to get effects that, for lack of a better term. Get you by. In other words, they are good enough to get the job done, but they aren't the best sounding out there.

That is what I was expecting when looking at the Helix Tremolos. Especially after taking a look at the tremolos found in the Line 6 HD500 series pedals.

I was super surprised to find that the Tremolos in the Helix kick the living crap out of the ones found in the HD500 series! The Too Long Didn't Read version of this, is that the Helix Tremolos could literally replace ~90% of my dedicated Tremolo collection. I was not only satisfied with what was offered, but impressed.

So let's break it down. We have 4 modes to choose from.

Optical Trem - Based on Fender Optical Trem Circuit
60s Bias Trem - Based on the Vox AC-15 Tremolo - Now this is the same thing that was stated about the M Series/HD500. But this to me sounds like a completely different implementation, and much better than the weird implementation of BIAS trem in the HD500. Take a look at my article on that if you want some more information on how they differ.
Tremolo/Auto Pan - Based on the Boss PN-2, but with a crap ton more control
Harmonic Tremolo - Says line 6 original, and as far as control ability it is.

So without even really delving into the modes, we already know we have our 3 basic types of Amp tremolo covered. Optical, Bias, and Harmonic. These are the same modes offered on the Flint or Source Audio Vertigo. These are the go to's for a lot of people.

Optical Mode - 

This mode is exactly what you expect, rather choppy/fluttery. It sounds very nice. The options are kept simple with speed, intensity and level. Their wave shape on this mode looks more like the Fender Twin mode on the MD-500 or the Tube mode on the Empress 2 tremolo, rather than the more choppy optical trem found in the Deluxe.

Optical mode at various depths

60's Bias Mode

Here, unlike the HD500 series, we actually get what we expect to see. Smooth sine wave tremolo. This is how it should be done.

Bias Mode - Various Depths

Here we get speed, level, and intensity controls. Even a toggle to switch from Tremolo to Vibrato, which was also found in amps back in the day! Bonus.

I was really impressed with how this mode sounded. It's smooth, it's deep and just a bit off center. It's everything I want in a Bias trem.

Harmonic Mode

Harmonic tremolo is often over looked in modelers/mfx units. Which is a shame because it's one of the cooler sounding effects.

Not here though, in fact. Harmonic mode was given the royal treatment. It has more control options than any other Trem mode.

Besides Speed and Intensity they have added a Wave Shape control that allows you to pick from the following shapes:

Reverse Sawtooth, Sawtooth, Triangle, Sine, Square, Inverse Sine, Random

Most of those shapes are pretty standard fair, except for Inverse Sine, which I haven't seen on any other pedal.

They offer Level AND Mix controls which are awesome, but then they add DutyCycle (On/off time control in the trem cycle) and control of the Bass and Treble frequencies in the Harmonic Tremolo!

In practice, this thing sounds just as good as any other Harmonic Tremolo I've played, and has more control-ability than most of them do as well. A++++

Tremolo/Auto Panner

The last mode is the catch all mode for sculpting anything that falls outside of the above 3 categories. 

This mode allows control of the Speed, Intensity, WaveShape, DutyCycle and Level. The wave shapes are the same offered in Harmonic mode.

Sawtooth Waveshape - Various Depths

The Duty Cycle control has no affect on the Sawtooth wave shape.

Reverse Sawtooth Waveshape - Various Depths

The Duty Cycle control has no affect on the Reverse Sawtooth Waveshape

Triangle Waveshape - Various Depths

Triangle Duty Cycle Adjustments

Here we see the Duty Cycle adjustment, rather than controlling the on/off time ratio, allows us to lean the wave shape left or right so that the peak comes earlier or later in the cycle. In essence, creating over lap in wave shapes (This renders sawtooth/reverse sawtooth redundant)

Sine Waveshape - Various Depths

The sine wave is very smooth and gets as deep as you need it to. 

Sine Duty Cycle Adjustments

Same theme here. A bit more rounded than the Triangle wave form when adjusting the Duty Cycle left or right.

Inverse Sine - Various Depths

The inverse sine at 100% depth is quite interesting. All you really get is blips. So at that depth, it isn't really the best representation of the wave form. Somewhere between 100 and 75% is probably the best. I used 75% depth to show what happens with the Duty Cycle.

Inverse Sine Duty Cycle Adjustments

Here we see the same theme, leaning the wave shape to the left or right in the cycle.

Square Wave - Various Depths

Square Wave Duty Cycle Adjustments

Square wave is where we actually see a representation of what Duty Cycle should actually be doing. Controlling the on/off time ratio in the cycle. So at 0% there is no sound, at 100% all signal is let through.  This is perfect for square wave Trem, as it allows you to dial in any amount of on/off time ratio you want to perfectly tailor your stutter sound.

Pro's
  - All amp trem bases covered, including Harmonic
  - All modes can run in Mono OR Stereo.
  - All trems actually sound great!
  - Catch all mode with a plethora of different wave shapes
  - The Ability to control ratio of on/off on the square wave
  - The ability to lean wave shapes left or right in the cycle

Con's

 - Duty Cycle control is not consistent on what it does. I've documented what it does above on each wave shape.