valve amplifier PL83 tube rebuilt
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48:11
valve amplifier high voltage power supply explained
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26:05
valve amplifier explained
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20:09
Ele achou no lixo! Funciona??
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16:59
Motores antigos raros dando partida com som que vai explodir seus ouvidos ▶3
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1:01:34
Tektronix 547 Valve Oscilloscope Repair - Part One
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19:57
Let’s Build a Low Voltage Vacuum Tube Audio Amplifier
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14:39
Este projeto de motor de 4 tempos com mais de 100 anos NÃO TEM VÁLVULAS!!! Podemos fazê-lo funcio...
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12:14