What does “all tube” mean?

If you’ve read about amps, especially ads about amps, you’ve probably seen this phrase attached to tube amps: “all-tube.” And you may have wondered what that meant. So, let’s take a minute and discuss the term, what it means, and why you shouldn’t pay any attention to it at all.

I’m not sure who first used the term “all tube,” but at some point it became the “all natural” of the amp world. Does the amp have tubes in the power section and the preamp? Call it “all tube circuitry.” But it’s important to separate “ad speak” from information, and that’s what we’re going to do.

We’re not going to go down the rabbit hole of hybrid amps, but in short, there are some amps that have a tube power section and solid state preamp and vice versa. These amps are not common, so we’re not really going to spend time on them here (another blog perhaps). But you can just assume that hybrid amps fall into the “not all tube” category.

Just doing a quick Google search for “all tube” amp brings up a bunch of results like a Fender Blues Junior. A tube amp for sure, but “all tube?” Hmm… Maybe not.

If we were to take the term “all tube” seriously, what would it mean? As far as I’m concerned, an “all tube” amp consists of a tube preamp, tube power amp, tube rectifier, and no solid state funny business to create artificial overdrive or distortion. It also means that if the amp has reverb and/or tremolo, those are controlled by tubes as well. Based on this definition, the Blues Junior fails by three measures: no tube rectifier, no tube reverb, and it has solid state circuitry to achieve overdrive in the Drive mode.

Do any of these factors make the Blues Junior an inferior amp? No. There are other factors that make a Blues Junior an inferior amp, but its lack of purely tube circuitry isn’t one of them.

There was a short period of time when people thought that “Class A” meant “really great tube amp,” but hopefully most people now know that Class A and Class AB are merely different types of operation rather than a qualitative difference. “All tube” is one option for how a tube amp can operate. A Fender 5E3 Tweed Deluxe is “all tube,” and a Fender Twin Reverb isn’t, but one isn’t better than the other.

So, if you find yourself asking, what does “all tube” mean, keep in mind that it’s just marketing language. If having an amp that is actually 100% run by tubes is important to you, do some research and see if the amp you’re considering meets that definition. But for the most part, if you see an amp described as “all tube,” just ignore it and look at the actual features and specifications. And if you have a question about amps, feel free to email us at adam@dexteramps.us or go to our Contact page.