The first electronic amplification of sound was done with Vacuum Tubes. We have pre-amp, power and rectifier vacuum tubes among other types in New Old Stock from the golden era of American & European manufacturing as well as current production tubes from today.
Vacuum Tube - 5AR4, Chinese
Chinese 5AR4 Vacuum Tube
Vacuum Tube - 12AU7, China
9 pin miniature preamp tube (Amplification Factor = 17)
Vacuum Tube - 12AT7, China
Chinese 12AT7 dual triode.
Vacuum Tube - 7025, China
7025 - 9 pin miniature preamp tube Made in China Lower hum/noise version of a 12AX7/ECC83 Voltage gain rating: 1 2 3 4 5 6 7 8 9 10 Lows Mids Highs
Vacuum Tube - 12AX7B, China
9 pin miniature preamp tube (Amplification Factor = 100). The Chinese 12AX7B is very similar in tone to its standard Chinese cousin, but the Bs seem to average in at slightly lower gain and noise.