Is there a difference...?

[Kwesi]

Is there a difference between increasing gain and boosting all available EQ frequencies on a preamp? Usually, I nudge everything up to around 2 o'clock but it seems to me that there should be no difference between doing this and just uping the gain a bit. However, when I do exactly that, it sounds different. What am I missing?

[JimmyM]

You're oversimplifying what EQ knobs do. When you turn a knob or boost a slider, you're boosting the center frequency most of all and causing peaks at that frequency, whereas adding gain doesn't change the EQ.

[Kwesi]

Oh yeah, I knew that much. I guess it's just kind of interesting to see how much difference there can be between the two.

[basscooker]

i think i already know the answer to this q, but i'll add it to the op's: is using my geb-7's volume slider as a boost essentially the same as having a second gain control?

[JimmyM]

Yep. It's taking your signal at whatever EQ you have set and boosting or cutting the overall volume, so it's exactly like a second gain control.

[Sartori]

Okay, say you have three EQ controls. Low, at 60hz or whatever, mid at 800hz, and high at 3khz.

If you boost all three, you're boosting specifically three ranges centered at 60hz, 800hz, and 3khz. While these center points might all be boosted equally relative to each other, and may even control a very wide spectrum of other frequencies, the frequencies in between these peaks will not be boosted as much. 370hz will be one such valley, and 1.9khz will be another. Depending of course on how wide the peaks are.

Turning up the gain, on the other hand, should be pretty much a boost to everything, keeping the frequency response relatively the same.

[billfitzmaurice]

Originally Posted by Kwesi

What am I missing?

You'll find it in here:
Signal Processing Fundamentals