So, I was researching tube bass amps, and came across this Ampeg SVT-2PRO.

So, it's all-tube. 9-band graphic equalizer. 300 watts of tube-driven power. Sounds great. Whenever I get a stack amp, I think I'll spring for this head.

But something I was wondering about this amp is this: When I was looking through the Owner's Manual, I noticed that it has two "channels," switching between the graphic equalizer and the regular equalizer. I came across these words under the graphic EQ section: "In the OUT position, there is no solid state circuitry in the signal path from input to power amp out." So, graphic EQs use solid state circuitry. I didn't know that. Here's my question (finally): How does solid state circuitry differ from tube circuitry (besides, obviously, using or not using tubes), and how much will the solid state circuitry from the EQ affect the tone?
Only play what you hear. If you don’t hear anything, don’t play anything.
-Chick Corea