Members guitarcapo Posted August 26, 2009 Members Share Posted August 26, 2009 It's that little wire coming off the top connecting the speaker to a 27K resistor and then to the cathode of the 12AX7 preamp tube. Basically it inhibits all of the signal that's going to the speaker by sending some of it back to the second preamp tube where phase cancellation eliminates some of the original signal. The idea of the negative feedback loop was created by early amp designers to eliminate distortion...but really it's a cheap fix to design flaws that should really be rectified earlier on in the signal chain. It's a cheap quick fix to an amp distorting...but not an elegant solution. Usually I eliminate the feedback loop in my amps or at least convert it to a presence control so I can adjust it. I usually will mod the cathode bypass cap and resistors at the power and preamp stages to adjust gain better than just squashing things at the end of the signal like that. Link to comment Share on other sites More sharing options...
Members Eric Hellstyle Posted August 26, 2009 Members Share Posted August 26, 2009 So are you saying that engaging the Modern Mode on a Recto, sets a higher capacitance, resulting in lower negative feedback and therefore the growlier, deeper, smoother less definied poweramp response you described? the modern mode cuts the negative feedback circuit in the vintage mode it has a 47k resistor (like a Plexi) the vintage modern is the less defined and smoother mode and that is also why it sounds less loud and less spikey you could ask why the modern sounds more spikey/dry if it cuts that circuit, considering that reducing negative feedback would make the opposite effect but then I have no idea of why does it happen Link to comment Share on other sites More sharing options...
Members Rear Naked Posted August 26, 2009 Members Share Posted August 26, 2009 Plexi's and JTM45's have the most negative feedback, past these it went down. Carry on. get it... negative feedback... get it Link to comment Share on other sites More sharing options...
Members tommythelurker Posted August 26, 2009 Members Share Posted August 26, 2009 the humor, sense it noobs! Link to comment Share on other sites More sharing options...
Members saxxamafone Posted August 28, 2009 Members Share Posted August 28, 2009 when the amp doesn't cheer or clap after you finish the song Link to comment Share on other sites More sharing options...
Members petejt Posted September 9, 2009 Author Members Share Posted September 9, 2009 I knew this was 2:100 related. I don't remember what the manual says, but I think in the Rectos, it's all about engaging the Modern mode. Oh ok, thanks. In a Dual Rectifier amp head I actually liked the Orange mode more than the Red. Link to comment Share on other sites More sharing options...
Members petejt Posted September 9, 2009 Author Members Share Posted September 9, 2009 the modern mode cuts the negative feedback circuit in the vintage mode it has a 47k resistor (like a Plexi) the vintage modern is the less defined and smoother mode and that is also why it sounds less loud and less spikey you could ask why the modern sounds more spikey/dry if it cuts that circuit, considering that reducing negative feedback would make the opposite effect but then I have no idea of why does it happen So you're saying that the Orange mode would sound more even/softer and wet? Somehow that makes sense, because when I tried the Orange mode it definitely sounded richer and "pulpy", not too squashy of course but had a nice saturation to it so to speak. Link to comment Share on other sites More sharing options...
Members MadKeithV Posted September 9, 2009 Members Share Posted September 9, 2009 the humor, sense it noobs! I thought negative feedback was what happened on eBay after you sold someone a 5150 and they didn't like it? Lots of negative feedback ! Link to comment Share on other sites More sharing options...
Members PaoloJM Posted September 9, 2009 Members Share Posted September 9, 2009 Oh ok, thanks. In a Dual Rectifier amp head I actually liked the Orange mode more than the Red. Have you broken this news to your father yet? :poke: Link to comment Share on other sites More sharing options...
Members guitarcapo Posted September 9, 2009 Members Share Posted September 9, 2009 The neg feedback loop reduces distortion, gain, and lowers the effective output impedance. I'm not sure what you mean by "squashing" things?please explain. squashing things=reducing gain, reducing distortion through phase cancellation directing the output signal back to an earlier stage of the amp... instead of reducing it by designing the preamp and power amp sections better. Sort of like building a hot rod car engine and then making it more managable/practical to drive in the city by putting a tiny exhaust pipe on it so it can't breathe efficiently. Link to comment Share on other sites More sharing options...
Members The Real MC Posted September 9, 2009 Members Share Posted September 9, 2009 Negative feedback is that heckler in the audience yelling YOU SUCK! Link to comment Share on other sites More sharing options...
Members grayeyes777 Posted September 9, 2009 Members Share Posted September 9, 2009 this thread reveals my stupidity. i don't get electronics at all. Link to comment Share on other sites More sharing options...
Members grayeyes777 Posted September 9, 2009 Members Share Posted September 9, 2009 Negative feedback is that heckler in the audience yelling YOU SUCK! LMAO!!!!!!!!!! Link to comment Share on other sites More sharing options...
Members Eric Hellstyle Posted September 9, 2009 Members Share Posted September 9, 2009 So you're saying that the Orange mode would sound more even/softer and wet? Somehow that makes sense, because when I tried the Orange mode it definitely sounded richer and "pulpy", not too squashy of course but had a nice saturation to it so to speak. I compared the vintage mode with the modern mode, not the orange channel with the red channelIf I remember clearly, the difference from the orange to the red is on the EQ section (less fat and less bright)maybe some kind of relay switching somewhere else, but I couldn't find it Link to comment Share on other sites More sharing options...
Members petejt Posted September 10, 2009 Author Members Share Posted September 10, 2009 Have you broken this news to your father yet? :poke: wtf what does my father have to do with amp tones? Link to comment Share on other sites More sharing options...
Members petejt Posted September 10, 2009 Author Members Share Posted September 10, 2009 I compared the vintage mode with the modern mode, not the orange channel with the red channelIf I remember clearly, the difference from the orange to the red is on the EQ section (less fat and less bright)maybe some kind of relay switching somewhere else, but I couldn't find it I though Orange WAS the vintage mode? And Red the modern mode? Dammit I can't remember. I'll have to borrow the Recto again and write down what I tried out. I just remember that I liked the sound no matter the combination of bold/spongy (mode) with diode/valve (rectifier), when it was in 'Orange'. I do remember though the volume being slightly less. Link to comment Share on other sites More sharing options...
Members PaoloJM Posted September 10, 2009 Members Share Posted September 10, 2009 I though Orange WAS the vintage mode? And Red the modern mode?Dammit I can't remember. I'll have to borrow the Recto again and write down what I tried out. I just remember that I liked the sound no matter the combination of bold/spongy (mode) with diode/valve (rectifier), when it was in 'Orange'.I do remember though the volume being slightly less. The rect has three channel, green, orange and red. Each channel has three modes vintage, raw and modern except for the green channel which has two clean and dirty I think. The volume drops a bit from modern to vintage/raw and also a bit when switching to the clean channel. Red channel has more pronounced high mids and highs compared to the orange. I also prefer the orange channel for rhythm playing. The father thing was just a lame ghey joke. Link to comment Share on other sites More sharing options...
Members petejt Posted September 10, 2009 Author Members Share Posted September 10, 2009 The rect has three channel, green, orange and red. Each channel has three modes vintage, raw and modern except for the green channel which has two clean and dirty I think.The volume drops a bit from modern to vintage/raw and also a bit when switching to the clean channel.Red channel has more pronounced high mids and highs compared to the orange.I also prefer the orange channel for rhythm playing. The father thing was just a lame ghey joke. The Dual Rectifier I played belongs to Vic, his is a 2-channel Rev. F version. It did have the Vintage, Raw & Modern modes though. Dammit I can't remember which it was now, I just remember "Orange" and the tone went from good to EXCELLENT! We were cloning channels back and forth and changing this and that, dammit I better borrow it again. Link to comment Share on other sites More sharing options...
Members PaoloJM Posted September 10, 2009 Members Share Posted September 10, 2009 The Dual Rectifier I played belongs to Vic, his is a 2-channel Rev. F version. It did have the Vintage, Raw & Modern modes though. Dammit I can't remember which it was now, I just remember "Orange" and the tone went from good to EXCELLENT! We were cloning channels back and forth and changing this and that, dammit I better borrow it again. Sorry, shoulda said I had had 3 channel rec, it was the solo head. Haven't used the 2 channel version Link to comment Share on other sites More sharing options...
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