In technical terms this is called the Doppler effect. The construction of the rotating cab is essential with the horn literary throwing the sound in all directions creating a unique resonance depending on the distance to the surrounding walls etc. The rotating speaker also resonates and creates dynamics and acoustics that a pedal canâ€™t replicate. So whatâ€˜s the difference between using a rotating speaker cab and a chorus? The split signal creates a stereo effect, which is something a chorus canâ€™t do by it self. The whole â€œsecretâ€ to Davidâ€™s setup though is that the rotating speaker cabs are mixed much lower than the amp rig. The result is a smooth warm tone with a mild chorusy swirl. This is easily done by simply splitting the signal from the guitar/pedal board and feeding it into the two setups. However, David would usually – and still is – blend the rotating speaker cabs with his Hiwatt rig. The tone is easily recognizable with a fat swirling sound with bite and grunge. David did this on Narrow Way, Brain Damage, Eclipse etc. The classic old school way of using Leslies is to just plug the guitar into the cab.

Rotating speakers have been an essential part of Davidâ€™s tone since the early 70s â€“ both on albums and not least in his stage setup. I often get questions regarding Davidâ€™s use of rotating speakers and how this effect can be achieved without actually having to buy a Leslie.

Cordovox amp and tonegenerator