JJ EL84 / 6BQ5 Power Tube JJ Electronic
The EL84 such as the JJ EL84 tube uses an output transformer with an impedance ratio of 5,000 ohms primary to 8 ohms secondary. The transformer should be designed to handle the power output of the amplifier and match the impedance of the speaker being used. Some recommended output transformers for EL84 amplifiers include the Hammond 125ESE, Edcor XSE15-8-5K. It's important to choose a high-quality transformer that is designed for your specific amplifier circuit and meets your performance requirements.