JJ Electronic 5751
This is a great tube for V1 if you are trying to drop the gain a little and improve headroom.
The JJ 5751 has all of the qualities we have come to expect from JJ Electronic, a nice tight low end, a natural open mid, a great harmonic structure and a sweet high end that is not brittle. This is a great tube for V1 if you're trying to drop the gain a little and improve headroom. You can also use a balanced version of this tube as a phase inverter to further increase headroom in amps that incorporate a long tail phase inverter circuit and usually use a 12AX7 or ECC83.