What do all those little knobs do?

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12-12-2005, 01:24 PM

effenay

50 Watt CAFz'r

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I'm trying to improve my understanding of amplifier technology, and am hoping that you guys can help. For years I've understood intuitively what all those little ***** on the side of my amps do, i.e. I understand how each adjustment will alter the sound. But I'd like to learn more from a technical perspective.

1. What exactly is Gain? My understanding is that the gain **** is supposed to control the amp's input sensitivity to the source's output level. Is this correct? Does this mean that the gain circuit is simply an attenuator? Can turning up the gain too far introduce distortion?

2. Bass Boost. How is bass boost implemented? What's the difference between using bass boost on an amp, and EQ'ing the signal externally instead?

3. Subsonic Filter. How is this different from a LPF and how is this feature implemented? When should it be used, and what are the advantages/disadvantages?

Thanks in advance for your educated comments and insight.

12-12-2005, 02:02 PM

Dereck Waller

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You are correct about a gain, turning it up can introduce noise, or raise the noise floor.

Bass boost is just a simple one band eq.

A subsonic filter (let's not get started on the merit of it's name) is actually a HPF.

12-12-2005, 05:47 PM

Fever

500 Watt CAFz'r

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To follow up on the subsonic filter, it's used to attenuate freq below its setting (hpf) so when your sub is in a ported enclosure you can attenuate the freq below the tuning freq of the enclosure where the sub can "unload" and nasty things can happen.