PreSonus Blog

The Ampire Sweetener


I work a lot with amp sims, and I love ’em. Well, except for one thing: Almost all of the ones that involve distortion exhibit what I call “the annoying frequency.” It’s hard to describe, but when it’s removed, you can definitely tell what’s missing—kind of a whistling sound, but without a sense of pitch. I have no idea why this particular type of artifact happens. It doesn’t go away if I increase the sample rate, choose a different pickup, switch guitars, or change my socks. And it’s worse with some amp sims than others; when reviewing a [particular amp sim by a PreSonus competitor] and I made the product manager aware of the annoying frequency, a subsequent expansion pack included a parametric equalizer so users could notch it out.

Granted, the 3rd gen Ampire is light years ahead of the 1st gen, as well as a lot of other amp sims out there. But we can still make it better, because the goal of the Friday Tip is to make things better, right?!? Besides, I’m an unreasonably picky guitar player.

Adding the EQ

Download the preset Ampire Sweetener.preset , and load it into the Pro EQ2 (Just open the .zip and double click the .preset file to install).  It will now have the curve shown in Fig. 1. Insert the Pro EQ2 after your Ampire amp and cab of choice, and the sound will magically lose its artifact.

Figure 1: Insert these notch filters after Ampire and its cab.

You have every right to skeptical—after all, you are reading this on the internet—so let’s listen to an audio example. The first half is with the EQ following the MCM800 amp and 4×12 MFB cab. The second half is with the EQ bypassed, but everything else the same. Both examples in the audio file are normalized to the same level. I’m pretty sure you’ll hear the artifact in the second half. Another way to hear the difference is play some power chords, and bypass the EQ stages to hear what they contribute to the sound.


The EQ’s curve isn’t only about the dual notches. There’s no need for super-high or -low frequencies, so those are reduced as well. Also, because the notches are in the high frequencies, adding a slight treble shelf compensates for the reduced amount of highs.

Figure 2: Reduce the high-shelf level and the two notches to sound more like the original amp sim/cab tone.

Now, this doesn’t mean you’ll like the end result better. You might prefer the sound with the artifact, and that’s fine. However, the artifact persists through the various amps and cabs. Inserting the Ampire Sweetener EQ removes that common element, which emphasizes the unique character, and tonal quality, of the individual amps and cabs. However, you can also “split the difference” by dialing back the parameters outlined in white (Fig. 2).

Finally, if you use other amp sims, many (if not most) will also benefit from one or two steep notches at the output. They probably won’t be the same frequencies, but they’ll likely be pretty close. The bad news is quite a few of them have far more prominent artifacts than Ampire, but the good news is the higher level makes it easier to hear them, so you can dial in their frequencies more quickly to notch them out.