Resistor and cap type,audible diference?

[R.G.]

Eric Johnson can determine what type of battery is in his overdrive pedal just by the sound of it.

... or so he says... 

I've learned it's not smart to bet either that someone can or can't do something until you have a lot more info about it.  Uri Geller can bend spoons, too.

[MKB]

I can clearly hear the difference with some Duracell 9V's and other brands in my wireless monitor pack; you get a Duracell every now and then that dies after 5 minutes of use instead of several hours.  Makes everything get quiet fast, and the first set sucks...

Eric Johnson also claims he has to remove the bottom plate screw in his Fuzz Face and hold it on with a rubber band in order for it to sound right.  I could buy the battery claim a lot easier than the bottom plate screw claim.  Batteries have internal impedances that vary according to discharge level, at leat there is some sort of explanation for that.

[Mark Hammer]

1)  What gets reported as some recording artist's preference and basis for preference is not always guaranteed to be a 100% accurate reflection of reality.  The aforementioned capability to detect battery differences likely refers to aging batteries, and the "screw thing" may well have something to do with keeping some things from contacting other things in a pinch.  Of course, maybe Keith Richards really DID snort his dad's ashes with cocaine.....

2) The qualifier of biased perception and the need for blind A/B testing is something that still needs emphasizing.  I point that out not to undermine the claims of those who "hear things" with component-type differences, but rather to be able to depend on, and use, the observations made.  Sometimes, component-type changes DO make a difference, and many times they don't.  For my part, it is just as much waste to dismiss any claims as preposterous with a wave of the hand as it it would be to accept them all.  Rigorous comparison is what lets you separate the wheat from the chaff.  Even that, in itself, is not the true goal.  The reason one needs to nail down when heard differences truly emerge from component type and not from component tolerances or bias or poor testing conditions is because it allows you to know what matters and why, and that is what lets you improve other things based on sound theory.  Which leads us to...

3) We get into this debate intermittently, and rarely does the qualifier of where get brought into the discussion.  Would I expect metal film resistors to have some impact on sonic quality if they were used in the voltage divider that supplies the Vref?  Not much, and certainly MUCH less than if we were talking about the input resistor to an op-amp set for a gain of 200.  Would I expect the type of capacitor used to set the gain of a transistor via the emitter-ground path to be as influential as a cap directly in the signal path?  Not really.  Both of those proclamations may well be naive on my part, but the fact remains that whenever we discuss component type/composition, we are broaching the potential for sonic differences, and nothing more.  What has to be asked is "What sort of potential change at this point in the circuit would a change in these component parameters potentially have?".  Until that question gets addressed, it's all just voodoo handwaving, and our component claims are simply hierophanies.

[dirk]

Carbon resistors change their resistance according to the voltage across it. You need a big voltage change to get a relatively small resistance change. So basically the only sane use, (add harmonics other than just noise) for a carbon resistor, is to use it with a tube as an anode load resistor.

[R.G.]

Correct, Dirk.

See "Use of Carbon Comp Resistors for Magic Mojo",  22 March 2002, at GEO, http://www.geofex.com.

[analogmike]

Electrolytics - Never compared brands so I can't comment. It never occurred to me to try. Electrolytics are electrolytics if you ask me.

Some are much better than others. I can hear the difference between 2 different models of 1uF caps of the same brand in our chorus pedal. Try to use the low inductance type for signal coupling caps or they can color your tone a bit (sometimes good, sometimes not). But we use the cheap big blue xicon in most places and find they sound awesome.

have fun!

[mac]

... As my father used to say, "I don't believe in witches, but I married one!" 

[BMF Effects]

Electrolytics - Never compared brands so I can't comment. It never occurred to me to try. Electrolytics are electrolytics if you ask me.

Some are much better than others. I can hear the difference between 2 different models of 1uF caps of the same brand in our chorus pedal. Try to use the low inductance type for signal coupling caps or they can color your tone a bit (sometimes good, sometimes not). But we use the cheap big blue xicon in most places and find they sound awesome.

have fun!

Re-reading that, I think I might have come across like a putz which was not my intention. Thanks to Mike for the schooling, I'll have to give it a try.

[RaceDriver205]

Eric Johnson also claims he has to remove the bottom plate screw in his Fuzz Face and hold it on with a rubber band in order for it to sound right.

What a loon! Maybe when all you do all day since you were a kid is play guitar, it gets to you!

[STOMPmole]

Eric Johnson can determine what type of battery is in his overdrive pedal just by the sound of it.

Too bad he couldn't hear that the tone of his last record sounded like it was recorded under a blanket. 

I think that caps make a difference depending on their location in the circuit (and the complexity of it) as does resistor type...but that's just my personal opinion based on my own limited and biased observations.