3. How about amp which power is within 10w?
It depend on whatsound you want. If you like clean sound, No problem, one 5w combo which has smaller speaker is good for you.But if you want distortion sound(many people want it). It is different.
There are fours components in total guitar amp syetem.
#1 preamp tube distortion( which let sound hard ,more metal), #2 power tube distortion( which let sound warm ) #3 speaker distortion ( I like regard it as No-Line of speaker)#4 the physical movement of air that your speakers produce at high volumes.
When the power of amp is smaller such as 5w.It is difficult to obtain more distortion from power tube. At same time, because the capacity of power tube is smaller, the distortion of preamp is limited . The power push coil of speaker is too smaller . The response of speaker will became bad.
4. What is the bestcombination of amp for hobbyists ?
We have discussed 100w and 5w guitar amp ,know disadvantges of two kind of amp.
What is good choice for hobbyist?
One amp, which power is within 50w , is good selection .At same time combination 50w amp with one attenuator will help you more.