kanuck wrote:But a practice amp would usually be solid state
Not necessarily.
There are plenty of low wattage tube amps out there.
Orange. Tiny terror
Vox. Night train
Blackstar. HT5
Messa.
MATAMP. Minimat
zvox. nano amp.
Fender.
Marshall.........
All of these companies make low watt tube amps.
Some, like the messa, are two voiced even.
Its important to understand that low watt doesn't mean low volume.
A 50 watt amp is not half as loud as a 100 watt amp.
What you get is lower head room.
So, where as a non master volume 100 watt amp will saturate with its channel volume at about 8, a 50 watt will give you the same tone at about 5.
Because the amp is saturating and compressing it gives the illusion that it is louder compared to a clean amp at the same volume if measured in actual dB's.
So, if you want a quite amp for small stages, choose a 30 to 50 watt amp and only run it with the volume open to the point just before break up.
The JTM45 is a 30 watt amp. If i run it with out bridging the inputs on 3 or 4 i get a crystal clear clean tone that i can push over the edge with a distortion pedal adding a small amount of extra gain. Alternatively i can run the amp on 5 or 6 and wind the volume pot back on my guitar for a clean tone, and wind it back up for a boost.
I can do all of this, and still be able to talk to some one with out shouting and still be heard.
If i turn the amp up above 6 or 7 it starts to saturate into a creamy compressed and dynamic over drive. It also starts to sustain and create feedback and also increases in volume about 30dB. This is where the isolation box comes it because it shaves off about 30dB of sound.
The wattage measurement in a tube amp is measuring how much input power is being generated before the out put stage.
This figure is an indication of what point the amp will distort. So a 30 watt amp will distort earlier than a 50 watt, and so on.
However, they will all be about the same volume give or take a couple of dB's.
In a real tube amp this is what produces the compression, saturation and clean head room that makes a real tube amp so dynamic.
The harder you hit the strings, the more wattage is produced at the input and the more compression is created as the head room is used up and distortion/saturation is produced. This is where the modelers all start to fail as they are not very good at modeling this aspect. They all only seem to be able to model this phenomenon in incremental steps.
I have both Guitar rig and amplitube on my computers and i have owned most of the pods since version 1.
All of these tools produce great clean tones and great distortion/over drive tones.
But none of them are able to accurately model the dynamic interplay of the energy produced by the guitar, and how that energy is interpreted by every stage of the amp to the speakers.