Using original 6J5 tube, original NE5532. 1x 6J5 Tube Preamplifier. This finished machine is a preamplifier, amplifier. Bluetooth : 4.2. Machine size: about 129 100 35MM (without tube height). The main filter capacitor uses the original 470UF/25V, and the coupling capacitor uses the imported capacitor 1UF.
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