PreSonus Blog

Friday Tip of the Week: The “Harmonic Tremolo” FX Chain

I did a Harmonic Tremolo as a Sonar FX Chain tip, and it was very popular—so here’s a Studio One-specific version. For those not familiar with the term, some of the older, Fender “brown” amps used a variation on the standard, amplitude-oriented tremolo which the company called “harmonic tremolo.” It splits the signal into high and low bands, and then an LFO amplitude-modulates them out of phase so that the while the highs get louder, the lows get softer and vice-versa. The sound is quite different from a standard tremolo, and many players feel the sound is “sweeter.” But unlike a guitar amp, you can sync this tremolo to the rhythm—and that makes it a useful addition to groove-oriented music as well.

Here’s the FX Chain “schematic.”

X-Trem needs to be in Pan Mode or this won’t work. As a result, this FX Chain must be inserted in a stereo track—a mono track switches X-Trem to Tremolo Mode (although a mono file inserted in a track set to stereo will work). If you switch a stereo track to mono accidentally and then switch it back to stereo, you’ll need to click on the Reset button in the FX Chain to return X-Trem to Pan Mode.

In Pan mode, while the left X-Trem channel gets louder, the other becomes softer and vice-versa. The Splitter (in Channel Split mode) sends the left split to a Pro EQ set to High Cut, while the right split goes to a Pro EQ set to Low Cut; their frequencies track to set the split point between the high and low bands.


Finally the two outputs go to a Dual Pan, which provides several functions.


Creating the FX Chain:


Crossover links the Pro EQ HC and LC Freq controls so you can adjust the split frequency between the high and low bands. At either the full clockwise or counter-clockwise position, the Harmonic Tremolo acts like a conventional tremolo.

Reset connects to the X-Trem Mode so you can reset it to Pan if needed.

LFO Speed controls the X-Trem speed from minimum to about 15 Hz. This control is inactive if the LFO Sync switch is on.

LFO Beats chooses the X-Trem sync rhythm and requires that the LFO Sync switch be on.

LFO Depth controls the X-Trem depth.

LFO Type chooses among the four standard waveforms (triangle, sine, sawtooth, square).

Lo/Hi Balance ties to the Dual Pan’s Input Bal knob. Fully counter-clockwise gives only the low band, clockwise gives only the high band, and the settings in between set the balance between the two bands.

Width controls the Dual Pan’s Width control. For the most authentic sound, leave this centered for mono operation (the Dual Pan should have Link enabled, and Pan set to <C>.

After assigning the controls, congratulations! You have your own Harmonic Tremolo… no soldering or guitar amps required!

Click here to download the effects chain described above. Just drag and drop it directly into a channel in Studio One!






  • rented

    Thanks for another great tip Craig! This sounds really nice, and no tubes where killed in the process either 🙂