So, I need to know about the following before I make the purchase.

1. Phase inverter - I did some research about this but I'm not sure whether it's important to know at this stage or not.

2. Number of pre-amp tubes - What effect on the sound, if any, does the number of pre-amp tubes have? (Say 4 tubes vs. 6 tubes.)

3. What's a rectifier?

4. Passive/active EQ? - Is this a pickup thing or is there active and passive eqs on amps as well?

5. Impedance - Do the various impedances affect the sound in any way? (4 ohms, 6, 18.)

6. Frontloaded vs. rearloaded cabs - I read that frontloaded cabs sound tighter whereas rearloaded cabs sound more resonant and warmer. Any opinions?

7. Series vs. parallel fx loop - Any difference in sound? Pros/cons?

Sorry for all these questions. I've been researching about this stuff for some time and I'm at the final stage before making the purchase. Thanks and I look forward to your replies.