Ultimate Scratch

The aim of the project is to realise an interface between a digital music source such as a CD player or a computer and a turntable. The overall work during this research was signal processing. One of the main parts of the project was a discovery of the CD players' signals and characteristics and a discovery of the characteristics of the vinyl disc and the turntable in order to determine the project specifications. To realise the project, many compromises had to be made in order to solve every problem as well as possible. The first part of the project was the realisation of the Fast Fourier Transform (FFT) of the vinyl saw tooth signal in order to determine the bandwidth of four saw tooth signals with different frequencies given that a saw tooth is composed of a fundamental and several harmonics. The aim of these measurements is to determine which signal is the most suitable for the realisation of the project. Then the work is focused on the vinyl disc signal in order to determine precisely the speed of rotation and the direction of rotation of the vinyl disc. And the final part is the generation of the signal which simulates the CD player jog dial (or wheel) signal. The detection of the direction of rotation is now working correctly and the generation of the CD player jog dial signals is possible. The last part which has not been completely achieved during the project is the accurate detection of the speed of rotation of the vinyl disc. This project is an on-going personal investigation into DJs system that is why this work will continue after the Master's projectSchool of Computing, Communications and Electronic