Electro Harmonix EL34

A tube in my amp recently gave up the ghost. It was one of the four KT88 tubes in the amplifier stage. I’d never changed tubes in the three years I’ve had this amp, changing just one tube was a bit risky and not very coherent in technical and sonic terms, so I decided to change the four original Cayin tubes. I had no reference or possible comparison with other tubes and I wanted to try something…