Everything we know about tubes, in one place. Whether you're swapping a single preamp tube, retubing a whole amp or chasing down a noise, start here.
Start here
- Find Tubes for Your Amp — pick your amp and get a kit with every tube it needs, in the right positions.
- Vacuum Tube Substitution Chart — which tubes swap safely: 12AX7 vs ECC83 vs 7025, 12AT7, 12AY7, EL34 vs 6L6, KT77, 5AR4 vs 5Y3.
- Best 12AX7 Tubes for Guitar — 10 brands compared by gain, tone and where each one works best.
- How to Test Vacuum Tubes — find the bad tube with the tap test, swap test or a tube tester.
Fix a problem
- Why Is My Tube Amp Buzzing, Humming or Crackling?
- How to Know Your Guitar Amp Needs New Tubes
- How to Test Vacuum Tubes
Choose the right tube
- EL34 vs 6L6: Which Power Tube Is Right for You?
- Best 12AX7 Tubes for Guitar
- Vacuum Tube Kits for Guitar and Hi-Fi Amps
- Best Tubes for Hi-Fi
Tube of the Month
A deep dive on one tube every month: history, tone, the amps that made it famous and which version to buy.
- 5AR4 / GZ34 Rectifier Tube Guide
- 12AT7 / ECC81 Preamp Tube Guide
- EL84 / 6BQ5 Power Tube Guide
- KT88 Power Tube Guide
- EL34 Power Tube Guide
- 6L6GC and 5881 Power Tube Guide
- 12AX7 / ECC83 Preamp Tube Guide
How tubes work
See all Tube Knowledge articles
How we test, match and back every tube
- Our Matching and Testing Process — burn-in, bench test, then matched and graded.
- 6-Month Warranty — every tube we sell is covered.
- Submit a Warranty Claim
Still have a question? Contact us with your amp model and we'll point you to the right tubes.
