Guitarists are known to be pretty traditional and therefore love tube amps.
Tube amps (mostly) sound quite well but at the same time they are (typically) pretty loud.
And especially in this day and age the use of PA systems is standard everywhere, a guitarist who plays just for fun or maybe even semi-professional will not be able to use a 100 Watts amp head.
Surely the one or the other might think that you could easily wind down your amp’s volume control.
But a tube amp sounds bests at its very own sweet spot at the border between a clean and a slightly crunched signal.
For some time there are small 5 Watts amplifiers that are supposed to be able to create a tube sound even in your bedroom.
But (depending on the speaker) at their sweet spots even these tiny wonders are they are still too loud.
Are there any alternatives?
For many guitarists transistor amps are not really an alternative, not even if you have set up your amp for a clean sound.
However, by using an overdrive pedal that constantly emulates the sound of a slightly overdriven tube amp in front of your transistor amp you will be able to make it sound quite well.
Therefor there are numerous “amp in a box” pedals but also the Boss BD-2 is very suitable for this purpose.
By this a transistor amp might becomes ideal as a pedal platform.
Amps with a tube preamp and a power amplifier circuit using a transistor are frequently overlooked.
The preamp of a so-called hybrid amp creates the typical sound of a tube amp while the power amp only amplifies the signal.
Ideally the power amp has only little effect on the sound so you will get a pretty nice sound on low levels.
1 watt amps
Because of their small speakers the tiny 1 watt amps mostly sound pretty thin. But on the other hand they are able to produce a really good tube amp sound on low levels.
The Fender Champion 600 for example is interesting if you are looking for Blackface Fender sounds.
The Vox Lil‘ Night Train is ideal to create the typical Vox sound and a Blackheart Killer Ant is able to sound like a Marshall JCM 800.
By combining one of these amps with a second (clean) one you will get a really good guitar sound.
Some time ago Korg invented the NuTube.
This chip-based tube emulation is supposed to sound like a tube.
I guess the fact that the Roland Blues Cube which has been invented in collaboration with Eric Johnson who is known to be a “tonesnob” uses this kind of technology, is a proof for the quality of sound.