EQ (B,M,T), Presence and Brt Swtch - What's the diff?

[R Anderson]

Probably a lot of gray area here between makers but in theory, what is the difference and purpose between these tone shaping tools?

 

I recognize that your ear shall be the ultimate judge - but what is supposed to be the distinctions and/or applications of each?

 

Thanks

R

[knucklefux]

in a typical amp, the TMB controls are passive, meaning that they lower the "volume" of the assigned band of frequencies relative to the others. so, turning the treble all the way up doesn't add treble, it just doesn't take any away.

 

presence is *typically* part of the negative feedback loop in the power section, and controls the high end frequency response of the power section. depth/resonance usually controls the bass response.

 

a bright switch *typically* adds a capacitor on one of the early gain stages that allows more high frequencies to pass through the preamp...effectively adding a high pass filter.

 

there are exceptions to all of these. for instance, the ubershcall's presence control is part of the preamp and the the power section's negative feedback loop.

 

there should be an audible difference between how the bright swtich, treble knob, and presence knob affect the tone and feel of the amp. unless you have tin ears, anyway:lol:

[R Anderson]

Excellent! Good stuff.

Thank you.

 

R