At Backert Labs, we only make home stereo preamps. Tube preamps.
But we have a lot of experience with different power amplifiers, and we are constantly asked about our opinions.
So today we answer, “Should you buy a tube power amp?”
1. Advantages of Tube Power Amps
There are several advantages to tube power amps:
- The Midrange. In general, tube power amps get the midrange right. Even inexpensive ones do this. And the midrange is where most of the music lives, so there is a good argument for just getting a tube power amp and being done with it. To get a solid-state amp that delivers the same high-resolution, layered, 3-dimensional, hypnotic midrange, you need to spend quite a bit more.
- Midrange, Again. Why again? Because it’s that good. The midrange you get from a tube power amp is to die for. We are talking Marilyn-Monroe-good. Ferrari good. Just absolutely outstanding.
- Overall Sound Quality: Some tube power amps have a way of making everything you play on your stereo sound great, or at least, enjoyable. Maybe it’s because they can add a bit of maple syrup warmth, and maybe that’s not strictly accurate, or maybe tube amps are just better. But for whatever reason, listening to a tube power amp is less likely to emphasize that spiky, glary, “digital” or annoying high frequency sound that is present on some recordings.
- Cost. Tube power amps can deliver this very pleasing sound quality with exceptional midrange at a very reasonable cost.
- Fun. There is just something cool about having a tube power amp in your system, especially if you like the visual aspect of seeing various tubes exposed (however, the tubes are not visible with every tube power amp).
2. Disadvantages of Tube Power Amps
There are several disadvantages to tube power amps, and they can be significant:
- Reliability. The power tubes, which are the large soda-can-sized ones, can fail. In fact, they will fail, eventually. (The other tubes in a power amp will also fail eventually, but will probably survive longer.) This means you will need to buy new power tubes every few years, to try and prevent a failure. Power tubes exist in a rough environment. They fail because they have a lot of energy pushed through them when they are operating. And when a power tube fails…. that leads to the next disadvantage:
- Reliability Again. When power tubes fail, they can take other parts of the power amp with them. Resistors. Parts of circuit boards. It can get pretty ugly. If this happens, it requires repair. Shipping a power amp to a repair facility is no fun. On the other hand, let’s be practical about it: nobody who buys a Ferrari expects to enjoy Toyota-like reliability.
- Cost. Power tubes are expensive, and the highly regarded ones can be extremely expensive. If you want to experiment with the sound of various power tubes, get ready to spend some money. Even if you don’t want top experiment, you’re going to need to replace those power tubes every few years. And to an extent, the other tubes in a power amp can also be costly if you want to find “the best”.
- Time. A tube power amp often needs to be on and warming up for a period of time to sound its best. Some say, at least 20 minutes, while others insist that 45 minutes is the minimum. Solid-state amps can also require warm-up time, but this is more often cited as a disadvantage for tube equipment because you can just leave your solid-state amp on 24/7. This is not advisable for tube preamps because you will use up your tubes quickly by doing this.
- Heat. Tube power amps get hot. They can even raise the temperature in your whole listening room, especially if you use large monobloc tube power amps. For this reason, listening to your tube power amp on a hot summer day can be downright uncomfortable if your room is medium/small and you don’t have good air conditioning. The intense heat generated by power amp tubes can also be a concern if you have animals or small children who might reach these components.
- Noise. Tubes usually produce some amount of hiss, although it’s often very quiet. If even a tiny amount of background noise bothers you, a tube amp may not be right for you.
- Sound Quality. Tube power amps can sound a bit warm. They sometimes lack “air”. Their bass sometimes lacks definition. Their rhythm and pace can sometimes feel a bit “slow”. To get really kick-butt bass, timing and airy sound from a tube power amp, you usually need to spend more (the same way you need to spend more if you want really outstanding midrange from a solid-state power amp).
To get even more information about the possible benefits of using a solid-state power amp, you can read this blog post.
3. The Bottom Line
Tube power amps aren’t for everyone. If you want the absolute best midrange with a pleasing overall sound quality and you don’t mind the heat, the reliability issues, and bass, airyness and rhythm that is a little less than perfect (or the cost required to overcome these issues), a tube power amp is probably right for you.
