REVIEW: ISP Decimator G-String


ISP Technologies was founded by Buck Waller, who previously revolutionised the things we don’t hear about guitar when he created the HUSH system for Rocktron. Noise types and requirements have changed a lot over the last few decades, and the ISP Decimator broke new ground a few years ago with its unprecedented tracking and sound quality, and the new Decimator G String takes things even further.

The Decimator series works a little differently to most noise gates. A regular noise gate will simply close the signal path when the input dips below a certain level. This can result in notes being chopped off unnaturally when you’re trying to hold a chord. The Decimator is completely different from this method. Instead it’s a single-ended noise reduction system which operates over a 1000 to 1 ratio using the company’s patented Time Vector Processing circuit. In plain english, this means the Decimator knows when you’re playing; when you’re not; and what to do about it.

Time Vector Processing refers to how the Decimator actually tracks the envelope of the input signal (instead of just using the mere presence of a signal above a threshold to determine whether the gate is open or closed). The best way of describing it is to imagine having a sound engineer continually adjusting the volume of the noise in perfect synchronicity with your playing.

The G String builds on the original Decimator by allowing you to plug the guitar directly into and through the pedal via a buffered output while also providing a separate channel of Decimator noise reduction for running noise reduction across your amp’s series effects loop too (or pedal chain, if you wish). I asked Waller himself to explain: “The Original Decimator pedal has an input and output jack and is designed to go between the guitar and amp or in the effects loop. When you insert the pedal in the effects loop and adjust the threshold to remove high gain noise in the high gain setting of the amp and or overdrive pedals and then switch to a clean setting the threshold will need to be adjusted or you will need to switch off the Decimator pedal. By contrast, with the G-String pedal the guitar is inserted into the guitar input and guitar output feeds the input of the chain and you then can insert the Decimator IN and OUT circuit into the effects loop. This allows the Decimator control circuit to track the guitar signal directly and puts the actual noise reduction circuit in the effects loop. Now switching from high gain to clean will not affect the signal seen at the input of the level detection circuit since this is reading the actual guitar signal. This means that you can change any setting on your amplifier or gain pedals and never need to change the threshold on the Decimator G-String pedal.

It’s kind of difficult to describe a pedal when by its very nature its reason for being is the complete absence of sound! The Decimator G String features the same sound quality as the original Decimator – that is to say, you have to do some major threshold-tweaking to get the signal to cut off unnaturally. I plugged the pedal into the front end of an Eganter Renegade head as well as through the Renegade’s buffered series effects loop. It takes balls to design a noise reduction unit that’s actually intended to be used in an effects loop where it will encounter effects such as delay, which would usually be cut off below a certain volume level with other noise reduction systems. The G String didn’t even break a sweat when my analog delay pedal trailed off – even when I turned on the pedal’s modulation effect for some additional shimmer and wobble. To make sure it wasn’t a fluke I piled on a distortion pedal and an octave divider through the amp’s front end – the sound was gloriously noisy when it was meant to be, but perfectly quiet when silence was needed. I plugged my Fender American Vintage ’62 Stratocaster Reissue into my Marshall set to kill, held a note, and the signal faded out naturally. It was a little unusual, actually – we guitarists are so used to expecting to hear 60-cycle hum from single coils that it can be a little confusing to not hear that element.

Of course, if you pile on too many noisy effects and you choose to not use the loop feature you risk your background noise equalling that of the guitar itself, which will confuse the Decimator circuitry, but there aren’t really any real-world musical situations in which you might turn all of your pedals on at once like that, are there? Hold a note (even with the 60-cycle hum generated by the single coil pickups on my Fender American Vintage ’62 Stratocaster Reissue) and the signal will fade out naturally.

The ISP Decimator G String will benefit every guitarist who has ever felt that noise was getting in the way of their self expression. It’s also especially good news for guitar techs and sound engineers who feel noise is getting in the way of their sanity.

[geo-out country=”Australia” note=””]CLICK HERE to buy the ISP Technologies Decimator G String from Musician’s Friend.[/geo-out]