Fuzz Face and Rangemaster placement in the chain

[JDoyle]

Another thing worth mentioning, Jay, is when you mention negative feedback I think you are referring to global negative feedback. 

Yours in nitpickery,

Doug

BUT - when I mention 'negative feedback' it could refer to either global (output to input of an entire amplifier with anything in between, as long as there is gain) or local (collector to base, drain to gate) - in either case a portion of the output is sampled and 'sent back' to the input, whereas with emitter/source degeneration, one is altering the input node's 'sensitivity' to signals presented to it.

I admit that it is mostly nitpickery - but I think it is an important distinction none the less. For example, you can have an emitter degenerated stage and still use negative feedback from the collector to the base, or to use a more concrete example, do something like one of the stages in the Big Muff with diodes facilitating the negative feedback, yet the stages are still emitter degenerated. If placing a resistor from the emitter to ground is negative feedback, how would one replace the resistor with diodes to achieve the same/similar result as in the stages of a Big Muff? If you placed them anti-parallel with the emitter resistor and fed them with a cap, you would get the opposite effect as in the Big Muff: once the Vth of the diodes was crossed, the gain would increase as they would then present a lower resistance than the emitter resistor.

Still, it IS nitpicky. 

Jay Doyle

[DougH]

Hey Jay, I wasn't accusing you of being nitpicky, I was just making a joke because I thought my response sound nitpicky.

Anyway, I completely agree- degenerative feedback is different and has different effects than both global or local negative feedback.

[frank_p]

One often makes a remark and only later sees how true it is. - Ludwig Wittgenstein

[JDoyle]

Hey Jay, I wasn't accusing you of being nitpicky, I was just making a joke because I thought my response sound nitpicky.

Anyway, I completely agree- degenerative feedback is different and has different effects than both global or local negative feedback.

No harm, no foul at all Doug - I was laughing even though I misunderstood!

Oh, one last thing for Frank - skip the Ghausi papers altogether, in my opinion. Brutal, mind numbing math. Though at one point he does say something to the effect of 'I'm not going to solve the equations any further because it gets too complex and the result is fairly useless.' I remember laughing at that...and then thinking 'Damn, I need to get out more...'

Have a great weekend all!

Jay Doyle

[frank_p]

(...) just because something exhibits one aspect of something else does not mean that it IS that something else. (...)

When in doubt, don't forget to read this Jay:

http://web.archive.org/web/20051210213153/http://budni.by.ru/oncertainty.html

Have a good weekend too.

HFP

[DougH]

Though at one point he does say something to the effect of 'I'm not going to solve the equations any further because it gets too complex and the result is fairly useless.'

If you ever want a mind-numbing good time, try plotting a Bode plot for a pedal circuit doing the calculations manually. There's a reason we use computer sims!

[frank_p]

I've not touched bode plots, poles and zeros, and all that stuff since about seven years.  Two weeks ago, I've found my copies of class notes from my maths classes and control-modelisation for mechatronics...   Ouf...  I've forgotten a lot of that stuff.  And what we had studied was not for "real electronic circuits".  It was for control: PIDs, stability, etc...   All my teachers worked in the vibro-acoustic research group so they were very enthusiasts of that kind of stuff.  So, since I liked sound theory, I took one master class (postgraduate) in vibro-acoustic.  I recall, it was tough theory (and I don't remember of most of what I've done there).  At that time in the lab they were conducting researches in vibration control in airplane structures, so there was a big model of a fuselage and one of it's wing (aluminium) of a commercial airplane, and all that structure was connected with tons of accelerometers and solenoids-actuators (I don't remember the real name) to develop a system that would control noise and vibration in real time by injecting impulsions in the real aluminium model.  It was impressing.  But, in fact the last time I touched that stuff was when I returned in school and it was for models of rheological and visco-elastic behavior of polymers.  Since molten plastics behavior models are often constituted of ensembles of masses, elastic elements (springs) and viscous elements (dampeners), the models are similar to filters.

A bit similar to that stuff:
http://www.it.uu.se/research/publications/lic/2005-005/2005-005.pdf

But for circuits with active components other than ideal opams and RCL, I really don't know what to do.  And still, I've lost the hand for that kind of things.  I would have to revise and study (a lot).  Perhaps one day, you guys will give me help for the electrical side.

So I understand, when you guys say that it is complex.  Even in my field I find it complex (and I am not a math addict). 

P.S.: And for bode plots I used Matlab, not my hand, neither electronic softwares.



See you soon !

Oh !  I have a HP gain-phase meter (3575A), it should help in that kind of stuff.

http://www.amplifier.cd/Test_Equipment/Hewlett_Packard/HP_meter/HP3575A.htm

[nooneknows]

Delays always sound bad in FRONT of an amp unless the amp has lots of headroom and is ultra clean

I'd say that U2's The Edge it's a brilliant example that what you say it's not completely true: he always uses delays in front of Vox AC30s pushed in overdrive..

[Ben N]

Brian May, too. Maybe AC30s are the exception!

[hairyandy]

Delays always sound bad in FRONT of an amp unless the amp has lots of headroom and is ultra clean

I'd say that U2's The Edge it's a brilliant example that what you say it's not completely true: he always uses delays in front of Vox AC30s pushed in overdrive..

Well yes and no.  You are partially correct, maybe I shouldn't have said "always".  Edge has done that in the past, mostly in the studio where it's easier to control just how hard he hits the amp with the delay.  He uses the old Korg SDD-3000 delays and the TC2290s for most of his delay sounds.  Since U2 has moved into bigger arenas at the end of the 80's he's relied less on the front end of the amp being crushed to achieve his distorted sound.  Here's a great explanation of his recent rig by his tech Dallas where he somewhat touches on this subject:

http://www.youtube.com/watch?v=RGHqoUOT_z4

An AC30 (at least a good, old one) is definitely a little more forgiving of this as well.  I think what I said does hold true in most situations though.  Try running a Memory Man through the front of a raging Marshall or, like I've done, a Trainwreck Express.  You probably won't like it much! 

Andy

[DougH]

If you don't use a lot of distortion you can get away with the delay first in the chain. A lot of the 60's guys plugged echoplexes into the front of their amps. Check out "James Gang Live" for an example. (In that case a lot of the echo was used for "freak out" stuff, not necessarily in a "musical" way like the syncopated stuff Edge and Gilmour do.)

There's no hard and fast rule for anything and you should always experiment. However, you'll find that putting the delay behind the distortion gives you a "cleaner" and more controlled sound, independent of the amt of distortion you use.

[JDoyle]

There's no hard and fast rule for anything and you should always experiment.

So true - I put my compressor (Ross inspired) AFTER all of my distortions. This goes against nearly everything ever written down about where to put a comp in the chain.

HOWEVER, in a live, paying, I'm-playing-with-other-people-on-a-stage-not-in-my-boxers-on-my-bed, situation, it was indespensible for keeping my clean and dirty rhythm tones the same level on stage, allowing me to kick it off for my solos at a higher level to cut through the mix.

Is it an ideal situation tone-wise? No, maybe not - though I didn't notice that as much as those I was playing with, and especially the soundman, would have noticed the jumping levels everytime I wanted a different tone - and the overall quality of the SONG and PERFORMANCE by the ENTIRE band is more important than any ethereal, perfect, rhythm tone I could create - especially if getting that tone meant degrading the whole.

In my opinion, anyone who proclaims a 'rule' of any sort in relation to music is admitting that they are looking backward - music is about innovation and change. But then we ARE guitarists, most of whom would spend more time, and be genuinely more interested in, the manufacturer and specific model number of a germanium transistor than a new tone control topology...

Regards,

Jay Doyle

[playon]

Getting back to the thread topic, I much prefer a fuzz followed by the treble booster, especially if you have some way of controlling the amount of low end cut on the TB... I like a pot better than the more common switch that chooses different input caps.  Anyway the reason I prefer it is that fuzz can get kind of tubby and flat and gets lost in a live playing situation... the TB adds a little mids and can be set to perfectly attenuate the low end of the fuzz.  On the other hand, I think a TB going into a fuzz sounds like crap, at least it does with my pedals.  Also I have some buffered pedals later in the chain and it doesn't seem to be hurting anything... go figure.