This is a Pentode Stereo Power-Amp experimental PCB set. EL84(6BQ5) Pentode is commonly used for various types of tube Amps and shows somewhat good performance even in simple class-A circuits. This circuit is also the one and often being used/published in 1960s hobby magazines. So actually nothing special but, since using Multi Purpose PCB, the whole making process is so much simplified for week-end completion. This PCB set doesn\'t includes Tubes, OPTs and Power trans to complete the function, however you can use wall socket AC110V for the B+ source, therefore only needed AC6V/2A Heater trance to work. Tubes 12AX7 can be replaced with 12AT7/12AU7/12BH7A, though the total gain and NF value will get smaller. Maybe you can enjoy not too much high-fidelity music, reaching 30-40kHz high, but somewhat mild and very nostalgic sound with this. Here below is the test result using Matsushita ETA-68E300(5k:8) as OPT.The test machine experiment\'s summary below;Tubes : 6BQ5(EL84) x 2 and 12AX7 x 1
Power Source : AC117V wall socket + 6.3V/2A Heater Transformer
B+ Voltage and the current : DC 304V/110mA(L+R)
Max. Power ETA-68E300(5k:8): 5.8W+5.8W（5%, NF:-6db)/(10%, 6.1W), /w 1kHz, 0.2Vrms InputThe circuit is very simple and flexible to change along with your knowledge, but not for beginners. I never recommend to whom they can not understand high voltage/impedance analog circuit. For it\'s simply dangerous, even digital experts are often ignorant unfortunately.Related You Tube bit interesting? Related

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