The circuit use one simple, but good power supply, is enough its armor-clad by the remainder circuit, if it needs, with a aluminium, so that we avoid the noises. All the circuit can be placed in a small box, from which will only come out the RCA jack, the main power cable, in the back box part and the Diode Led D1, in front part. Good its are placed a Fuse and a good small switch. The signal from the circuit outputs, with a good cable, is led to a free LINE input of amplifier or preamplifier. If the output signal level, is not that we want, we can change the resistors R9-22, with other value so that we adapt the level.