The 12ax7 tube is arguably the most popular audio vacuum tube that has ever been created. It’s popularity is driven by use in many Hi-Fi tube amplifiers and especially guitar amplifiers, where it’s pushed really hard and burns out fairly quickly. Introduced in May of 1947, the tube gained almost immediate popularity due to its very high gain – mu: 100, so it amplifies voltage 100x! Although I’ve seen JJ and Sovtek 12ax7 tubes go as high as 115, but that’s not up to spec.
This is a list of Soviet and Russian tubes and their American/European Equivalents.Continue reading
Another post in a series of legendary tube brands. This time I will go into details of General Electric (GE) Five-Star Brand.Continue reading
Practically all tubes in Gold Brand series have earned legendary status among audiophiles. In this article I will go into details of the brand and what makes it so special.Continue reading
There are so many great tubes with what’s called Foil Getter. But what is it? How does it look?Continue reading
Which 6sn7 tube won the right to be called the best and the worst?
Updated August 9th, 2020Continue reading
Which 12au7/5814 tube won the right to be called the best and the worst?
Updated August 7th, 2020Continue reading
Which 12ax7/5751 tube won the right to be called the best and the worst?
Updated August 5th, 2020Continue reading
Since we started this site in 2012, a lot of people contributed their reviews and ratings for various vacuum tubes. So 8 years have passed, which tubes have the highest rating?
Updated August 2nd, 2020Continue reading
There is a lot of confusion about matching tubes. It starts with some vendors, especially on eBay, matching tubes by the way they look (visual matching) to matching on multiple electrical parameters at the same time.
There are 4 parameters that could be used to match preamp tubes:
- Transconductance – Gm
- Voltage Gain – Mu
- Plate Current – Ip
- Tube Age