4 Knob Compressor? ... Oooooh Matron In case you didn't know, Robert Keeley is regarded as the Godfather of the boutique pedal world. Its definitively true to say Keeley are no longer a boutique company BUT for many many MANY guitarists Robert was their very first introduction into the world of "Oh yeah that's a great pedal, send it to me and I'll make it even better". The term "Keeley moded" is now a common phrase across the globe, and has encouraged a huge number of builders to have a go themselves which directly lead to the massive pedal boom we live in today. Of course, if your regularly improving others pedals then it makes good sense to start producing a version of them with the upgrades all ready in place and from there to start producing a range of pedals. From here the Keeley 2 & 4 knob compressors were born and were the finishing touch in solidifying Keeley's place on the Mount Olympus of the gear world. The Compressor Plus succeeded the 2 & 4 knob compressors and went on to become the single most popular compressor ever sold, in excess of 80,000 units have been made also making it Keeley's most successful pedal ever. But ... Why? Well its pretty simple really and that's the key, simplicity! Keeley made a compressor which gives you studio quality compression and made it incredibly simple to dial in to the extent that the release control is assigned to a two way switch perfectly dialled in for humbuckers or single coils. All the tricky work has been done for us leaving enough control to personalise our tone. This could have gone horribly wrong but the team over at Keeley have great experience and great ears so instead it worked out just fine!