What do Oil Caps do and how do they effect sound?

Sean is correct, but remember that many speakers produce their best sound by way of voltage, not wattage. Soundlab is a perfect example.

The ultra high rail voltages of tube amps will typically drive this load better than transistors.

For example, some SET Tube amps rated as low as 20 watts run 1,000 volt (or higher) rail voltage and therefore can swing enough drive the big Soundlabs to near 90 DB SPL.

No 20 watt transistor amp I am aware of would work on big Soundlabs. In addition, transistors hate big impedances in bass, reducing power to a fraction of it's textbook rating. Some tube amps actually produce MORE power at 30 ohms than 8 ohms.

In other words, the answer is not always easy to determine by numbers or text. As always, listening is the most important test you can make.

Point I was making was, published specifications don't tell us the whole story. Many people assume that the quality, power and sound of an amplifier may be determined by what the manufacturer puts into print.

I admit that some statistics are laughable, but that is not what I was referring to.

I encourage people to think about the variables effecting end results. Even specifications not discussed in literature. That's why a personal audition of the gear is so important.