In this study, two different types of power supply are used in order to analyze the influence of the current output characteristics on the electric discharge characteristics. Three different plasma spray guns, namely F4, 9MB and SinplexPro, are studied with the use of different powder feedstock materials (Metco 204C-NS, Metco 71VF-NS, Metco 450NS and Hydroxyapatite C) by measuring the real-time gun voltage and current as well as the frequency spectra of the electric discharge during the spray process. In addition, a metallurgical analysis of the spray coatings is done in order to investigate the influence of the electric discharge characteristics on the spray coating quality in terms of the average coating porosity, hardness, deposition efficiency, degree of oxidation and microstructure.