It’has always a little bit of distortion. I’ve tested with dummy load of 8 ohm, with speakers, also and with signal generator, sin wave, square wave 1Khz and oscilloscope. I changed the input tension between 24 to 28 volt, nothing to do. I’ve add 10.000+10.000 microfarad cap. with the same result. Coul’d you send me the schematics please?