Given this excellent performance in my High Fidelity system, I would agree; these tubes contribute no discernable distortion which would make them undesirable in a most guitar amplifiers, but it makes them AWESOME in a home stereo!My choice of the Mullards for the 12AX7 and the 12AU7 tubes was based on similar research where the Mullards were being criticized as too clean for guitar amp service but praising the small Tung-Sol tubes for a sweet guitar amp tone

With these tubes, I have no doubt these amplifiers are acting as good as or better that their impressive specs