daveinspain Posted July 27, 2011 Share Posted July 27, 2011 Ok, stupid question time... What does the presence knob actually do? I have played and tweeked the hell out of many a presence knob and it doesn't seem to do anything... I used to think it was a mid range boost but that doesn't really answer how it affects your sound.... Andy? Link to comment Share on other sites More sharing options...
damian Posted July 27, 2011 Share Posted July 27, 2011 Duane V runs 'presence' full on.................. Presence, in short, isn't quite a top end boost, but accentuates the upper mids...... Or better said, it squishes the dynamic range............ I consider it a tone killer......Andy knows how to describe it much better................... Link to comment Share on other sites More sharing options...
djroge1 Posted July 27, 2011 Share Posted July 27, 2011 Technically speaking it's part of a feedback loop. The idea is to return some of the output signal to the front of the circuit. It can be either negative or positive and either voltage or current - 4 different types. If the effect is to increase the gain the feedback is positive. If it is to decrease gain it is a negative feedback. As part of the process of returning the output to an earlier stage it affects the frequency range - why you get a slight boost in certain frequencies. Link to comment Share on other sites More sharing options...
Guest farnsbarns Posted July 27, 2011 Share Posted July 27, 2011 It's my birthday in 3 weeks. I hope to get some presence. Link to comment Share on other sites More sharing options...
duane v Posted July 27, 2011 Share Posted July 27, 2011 Duane V runs 'presence' full on.................. Yeppers Both amps the presence is always pegged whether playing clean or dirty Link to comment Share on other sites More sharing options...
rct Posted July 27, 2011 Share Posted July 27, 2011 Technically speaking it's part of a feedback loop. The idea is to return some of the output signal to the front of the circuit. It can be either negative or positive and either voltage or current - 4 different types. If the effect is to increase the gain the feedback is positive. If it is to decrease gain it is a negative feedback. As part of the process of returning the output to an earlier stage it affects the frequency range - why you get a slight boost in certain frequencies. Yes to all of that, with one caveat(man that sounds so good) to the original poster that might be helpful: Volume. Presence matters when yer Marshall is flapping yer new Cheap Jeans, helps the highs drive over same as the lows, sorta. Makes for more "even" delicious grind coming out of all them Celestions. Volume Matters. Outside that, it's pretty useless, even at todays gig volumes, hence the absence of presence today. rct Link to comment Share on other sites More sharing options...
Valeriy Posted July 27, 2011 Share Posted July 27, 2011 Incidentally, I have never distinguished between the knob too. But I have a special active electronics into my guitar that gives me the desired effect of presence and now that knob on any amp in general is not relevant for me. Link to comment Share on other sites More sharing options...
Big Bill Posted July 27, 2011 Share Posted July 27, 2011 Link to comment Share on other sites More sharing options...
damian Posted July 28, 2011 Share Posted July 28, 2011 Interesting, rct and djrogel..........I'll be doing some research...........just to learn............. Farnsbarns; On your birthday, do you hope to GAIN a lot of presence ?????? Does TONE age well ?????? Link to comment Share on other sites More sharing options...
Andy R Posted July 28, 2011 Share Posted July 28, 2011 There isn't really an easy answer as it involves quite a few concepts. It's not a "Tone" control like your bass, mid, and high knobs that are using resistance and capacitance filtering to control how the tone is shaped in the preamp section of the amp. Essentially what it is doing is adjusting the amount of phase canceling which also has a perceived tonal effect but it also has an effect on the gain/distortion as well. This is accomplished as previously stated by whats called a negative feed back loop. In effect it supposed provide the audible perception of of the amp being more or less behind or upfront in the "Mix". I think this was the marketing version of how it works. Changing the capacitor that is attached to the Presence control and which "Tap" the negative feeback wire is connected to is a quick way to change the response and gain of your tone controls of the amp. Definitely Changing where the NFC wire is connected is a simple and easy way to play with your tone. Sometimes it is connected to the center tap of the speaker OHm selector. In this case it changes as you change OHM selection. Obviously you want to try to keep your speaker selection consistent with your cabinet so this isn't a very good way to have it. Depending on the amp it could also be connected to the 4 8 or 16 ohm tap and especially on older Marshalls wasn't consistent. Which is another reason why two amps that appear to be identical can sound completely different. Try changing it and see what you think. It makes a big difference and and extremely easy "mod". I have been thinking about actually adding a switch to allow me to change this on the fly.... This is just my take on it and is not gospel by any means... Just my perception and understanding. Andy Link to comment Share on other sites More sharing options...
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