The W140 probably has a subwoofer, that might explain the wow factor. Harmonics are produced through the whole signal path. A subwoofer which plays a pure bass tone, let's say 36Hz, will produce its own harmonics due to the reactive properties of the enclosure, the materials and so on, but not before the amplifier stage produces some of its own harmonics. That 36Hz tone, if coming from a kick drum will have its accompanying harmonics produced at the source itself. An ideal amplification system tries to be transparent. It will not introduce any harmonics if you don't overdrive the unit. If it's recorded too hot on tape you will get harmonics. In fact, any gain stage, if overdriven, will produce harmonics... some desirable, some not. Anyway, what is my point? If the recording was made without overdriving any of these stages then you'll get at least the harmonics produced by the instrument itself. This gives it its timbre. Tweeking the eq to bring out these harmonics makes it sound unnatural and forced. You also run into all kinds of phase problems if you tweek the eq too much. I'd say 3db is about the max difference you should have between any frequency. Remember, 3db difference requires twice the power, so if your're already pushing 40 watts out of your 80 watt amps, you're gonna double your power draw.

Kuan