amp companies (Fender and Mesa/Boogie, for example) use either 6L6s or 6V6s. Other amps use 12AU7 or 12AT7 tubes, which are similar to the 12AX7 but have lower gain.

And most use 12AX7 (aka ECC83) preamp tubes. Most tube amps need multiple preamp tubes to perform various functions. First, let’s look at some different types of tubes. But remember, I’m not an amp tech: This advice comes solely from my experience as a player. I'll attempt to shed some light on these mysterious glass bottles and offer some tips on how to keep your amp rocking when you run into tube-related issues.

Tubes can and do wear out and fail, which can wreak havoc on your gigs and sessions. Yet with so much confusion and misinformation, tubes can be a daunting subject for even the most experienced guitarists. But you probably hate them too! The magic bounce, compression, and grind that tubes produce form the tonal foundation for almost every great electric guitarist-past and present. As an electric guitarist, you likely love tubes.

Self bias guitar amp