The best replacement for tube amp is solid state.

The best alternatives to tube amp are rated as following:
★★★★★  solid state
★  valve amp
★  modeling amp
★  solid state amp
★  digital amp
★  combo amp
★  transistor
★  line 6
★  transistor amp
  axe fx 2
  modeling
  axe fx
  solid state amps
  tube preamp
  modeler
  ss amp

Your alternative for tube amp is not listed? Suggest!
Speaking about tube amp, one probably shouldn't forget about solid state preamp.

Other search terms related to tube amp and their ratings are:
★★★★★ solid state preamp
You have in mind a companion for tube amp and it is not yet here? Propose!



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tube amp
solid state
valve amp