Have you been scratching your head about 12AX7, 12AT7, and 12AU7 Preamp Tubes? Well, our most frequently asked questions about them are answered here.
Preamp Tube FAQ: What is the most common Preamp Tube?
In answer to our first Preamp Tube FAQ, we can say that the 12AX7 is, by far, the most common type of Preamp Tube used in guitar amplifiers. The 12AX7 has the highest gain value, and it is, therefore, the one most preamps are designed to use. You can often substitute lower gain tubes for the 12AX7s without harming your amplifier.