Carl Martin Classic Optical Envelope review

At first glance, newcomers would be forgiven for thinking that the controls on this funky little pedal looks a little bit confusing.

The reality is that each of the controls is reassuringly simple, distinct and interactive.

The tone control is obvious enough and tames the higher frequencies, while the drive control dictates how sensitive the effect is to your picking attack. The bandwidth of the sweep itself is adjusted via the Q control.

On lower settings the wah is wide and less aggressive, but when pushed up offers a more immediate and aggressive sound. The level control keeps your signal in line with that of your amplifier, and then there's the select switch, which alternates between three presets.

The high and band pass settings give you a sharper or deeper voice to work from, and the low pass takes this a little further and is also designed to work well with bass guitars. All the tones on offer really are very good, with rich low-end snarls and crisp, funky highs covering a lot of different applications.

At £99, you may think you'd be better off with an actual wah pedal. A valid argument, but an optical filter can react more quickly (and accurately) to your playing technique than rocking your foot back and forth; if that appeals to you, then quality becomes important.