Top-Quality Material: ECC83 is precision engineered using high-quality materials for exceptional audio fidelity, replacing 12AX7, ECC803, and B759 tubes. Rigorously Tested: Each tube undergoes stringent testing to reliability and superior performance. Our testing guarantees parameter accuracy and consistency. ECC83: High μ m low noise dual triode small nine pin transistor for voltage amplification in audio amplification circuits, reverse phase driven push-pull amplification. ECC83 undergoes testing for humming, noise, and microphone effects, and is designed differently for different users. Therefore, when purchasing this tube, customers should inform the manufacturer of the hot wire voltage value of the model in order to obtain a high-performance product. This tube can be used for the first stage amplification of high gain amplifiers. The functions and electrical parameters of 12AX7B and ECC83 are identical Due to different batches, there may be differences in product appearance and printed text, which not affect use Colour:As Shown Material:Glass Package Contents: 2 x ECC83 electronic tube Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.