Prism Sound: OVER-KILLER Inline Soft Clip Limiter

Simply put, the OVER-KILLER is Prism Sound’s soft clip limiter circuit from their vaunted line of converters, made into a passive, standalone device. It is housed in a Switchcraft XLR barrel, has no controls whatsoever, and is one of the easiest ways I’ve found to increase maximum RMS without sacrificing the perceptual impact of the transient content of your mix. It also importantly addresses the need for a high quality soft clip limiter circuit in the analog domain and retails for around $200.

The learning curve is nonexistent. You simply plug it in, and the red lights go away. Bypass is achieved by unplugging it. I tested the OVER-KILLER with a range of source material from one-shot samples, to unmastered mixes, to commercially released mastered albums. Mastered material was the most ruthless test, since that source material will have likely been compressed, limited, and clipped at several stages already.

I found the OVER-KILLER to be entirely transparent at lower overall RMS. Two copies of the same file, one dry and one processed through the OVER-KILLER, nulled completely when playing back out of phase, even after the D/A to A/D loop inherently required for this test.

Louder files naturally had more subtle reactions, as more of the audible spectrum is pushed towards the threshold. I was still able to get a huge amount of gain reduction in a null test, but experienced increased broadband artifacts left behind based on the overall loudness of the incoming signal. Put another way, as the overall loudness going into the OVER-KILLER increased, more low end tended to appear in the resultant null test. Prism describes the OVER-KILLER circuit as it exists in their range of conversion as a “progressive limiter,” and I believe these observations are consistent with that design. However, I wondered how much of that circuit can be ported directly into this passive, standalone platform. This curiosity led me to open one of the barrels, naturally, and I was equally delighted and chagrined to see the circuit buried in goo like a Bill Finnegan-made Klon Centaur overdrive pedal.

Qualitatively, I quite enjoyed the sound of the OVER-KILLER when I’d hear it working. I found the increasingly sharp edges of the soft clip limit approaching the clip point to be pleasing on the right source material. I will buy this pair and am excited to add this inexpensive and incredibly useful gadget to the analog tool kit.