The circuit presented was obtained from RCA 1971 Tubes Manua. It is very popular circuit at the time, being used in conjunction with turntable with ceramic capsules. This is a project that can be developed by collectors who have a record player with such capsules.
In the RCA configuration it uses one valve 7199, a high-gain triode-pentode with power between 230 and 300 V. This power can be obtained with the own amplifier circuit which operate. Consumption is very low, not overloading the source.
The output has an impedance of Ω 5000 Ω, and the input is high impedance. The circuit is shown in Figure 1.
