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Difference in Capacitors
- Thread starter pedroims
- Start date
I'd be more than happy to give you any helpful information I was privy to. I think you're misunderstanding my genuine curiosity as some challenge to your wisdom, in which case all I can do is throw my hands up. I don't claim to be an electronics expert by any stretch and was asking questions in search of better understanding. Sorry it was so traumatizing....
Tell me a band where the bassist sweeps the tone control for sonic effect.
I do it in one band quite a bit. For one section, I simulate a "wah" type effect with the sweep of my tone pot. For another project I leave my tone rolled completely off or almost off, but for this one, I use it as an integral part of the music because the sweep is so broad and apparent. It's funny you should bring it up, but Roy Buchanan is exactly who inspired the techniques I've been working on with this group. Mostly chord phrasing and double stops involving the sweep of my tone as opposed to volume knob. Sometimes I incorporate both in one cohesive movement, sometimes I use a technique where I pre position the pots with my hand and swell and return to those positions (still working on that one)
It suits the project I'm in and its another tool in the belt.
That sounds cool. I listen to guitarists like Roy and Jeff Beck. The problem I find is that if I start rolling the volume knob people think you are messing around. Maybe that is the musical company I keep.
Jeff Beck treats his Strats like a science lab constantly ticking over. I cannot think of a bassist who treats each note like a specially-mixed colour of paint. Maybe you are the one? 
That sounds cool. I listen to guitarists like Roy and Jeff Beck. The problem I find is that if I start rolling the volume knob people think you are messing around. Maybe that is the musical company I keep.
I did a lot of experimenting with cap values and pots to get the right mix. I eventually settled back at .047 and a CTS 250k "open back" pot (basically standard Fender issue with a tighter tolerance). I was using a Bourns on the tone pot because the torque was so fast but my local shop stopped carrying them and for some reason, its hard to find the 250k solid shaft online for a reasonable price unless I buy 25 of them!
On my P I'm using a metalised polyester 0.1 uF cap at the moment. I scrounged it out of an old stereo I was tasked with breaking up. I think the pots are 250 k CTS units. I like the dubby quality you get with a 0.1 uF... it cuts everything but the fundamental!
As promised, I measured the values of the five caps I've been testing. I used a cheap ($100) capacitor tester with a brand new 9V battery. Advertised accuracy is +/- .02% of reading. Absolute accuracy was not the goal. The challenge was relative values possibly being different enough to account for any difference in sound that I have been hearing.
To eliminate the temperature factor, I let the caps sit on my desk for 30 minutes so temps could stabilize. During testing, I did not touch the caps. I used the alligator clips on the leads of the tester to grab the cap leads for each measurement. Here is what I found...
Orange Drop .047 - .050uf
Russian PIO .047 - .052uf
Difference - .002uf
Orange Drop .1 - .104uf (Cap is in fact labeled '104')
Russian PIO .1 - .106uf
Vitamin Q .1 - .105uf
Max difference - .002uf
I honestly didn't expect them to be this close!
I think this rules out variation in cap values as a cause of the differences in sound that I think I hear.
To eliminate the temperature factor, I let the caps sit on my desk for 30 minutes so temps could stabilize. During testing, I did not touch the caps. I used the alligator clips on the leads of the tester to grab the cap leads for each measurement. Here is what I found...
Orange Drop .047 - .050uf
Russian PIO .047 - .052uf
Difference - .002uf
Orange Drop .1 - .104uf (Cap is in fact labeled '104')
Russian PIO .1 - .106uf
Vitamin Q .1 - .105uf
Max difference - .002uf
I honestly didn't expect them to be this close!
I think this rules out variation in cap values as a cause of the differences in sound that I think I hear.
I believe the answer may lie in doing a truly double blind test, where if the values are the same I would suggest it extremely unlikely that anyone will be able to detect any difference.
Here's the original video I included excerpts from in my second video (with Ethan Winer's and James Johnston's consent). If you haven't seen it yet I very strongly suggest you at less watch from around 1:05 to 5:15.
Invalid Link Removed
I listened to the segment David suggested.
I think I understand what was said.
In my original post and in subsequent posts, I said I could hear a difference, not that one sounded better than the other or that I preferred one over the other. Between Orange Drop and Russian PIO, I had no trouble hearing a difference. Between Russian PIO and Vitamin Q... not so sure. They are, after all, of similar, if not the same composition.
Yes, I did expect to hear a difference so my perceptions could easily be dismissed as being self-fulfilling. I understand that.
I also watched David's video about the 3 + 1 test. I'm sure that would legitimize things for me if I performed such a blind test and could still hear a difference (or not!).
Meanwhile, you've got me questioning myself now. I may have my son clip in a cap and play, then change caps (or go through the motions of changing caps -his choice) and play again, repeating this process a few times. If I say I notice a difference when all he did was go through the motions, then you'll have me!
In the end, I'm going to choose one of the .047's and one of the .1's and install them along with a push-pull cap selector switch on the tone pot and play my bass.
I think I understand what was said.
In my original post and in subsequent posts, I said I could hear a difference, not that one sounded better than the other or that I preferred one over the other. Between Orange Drop and Russian PIO, I had no trouble hearing a difference. Between Russian PIO and Vitamin Q... not so sure. They are, after all, of similar, if not the same composition.
Yes, I did expect to hear a difference so my perceptions could easily be dismissed as being self-fulfilling. I understand that.
I also watched David's video about the 3 + 1 test. I'm sure that would legitimize things for me if I performed such a blind test and could still hear a difference (or not!).
Meanwhile, you've got me questioning myself now. I may have my son clip in a cap and play, then change caps (or go through the motions of changing caps -his choice) and play again, repeating this process a few times. If I say I notice a difference when all he did was go through the motions, then you'll have me!
In the end, I'm going to choose one of the .047's and one of the .1's and install them along with a push-pull cap selector switch on the tone pot and play my bass.
I spoke with one of my brainiac audio engineers about this today. For this application of milivolts and micro amps of audio, he agrees there is no audible difference. However, in certain applications of high power, such as in speaker crossovers, the type of caps CAN make a difference. This may be how such a rumor got started. Also, he said that the Orange Drop caps were designed for high voltage, and were commonly used in tube amps which is why they were a handy stock item for some bass makers to put in a guitar. Other than the physical size, an 0.1 is an 0.1.
Further, I am recalling meetings over the years with some of the makers of the ultimate top end tweakophile stereo gear, and cap type was NEVER discussed in terms of sound quality. Only for accuracy and stability. And these are the ultimate snake oil types.
My engineer also said that in some of the high end audio gear he has dissected, such as Mackie mixers, the little green poly caps are what was always used. I know Greg Mackie well, and I can tell you that if a certain cap would have made a sound difference, he would have used it. Period.
Further, I am recalling meetings over the years with some of the makers of the ultimate top end tweakophile stereo gear, and cap type was NEVER discussed in terms of sound quality. Only for accuracy and stability. And these are the ultimate snake oil types.
My engineer also said that in some of the high end audio gear he has dissected, such as Mackie mixers, the little green poly caps are what was always used. I know Greg Mackie well, and I can tell you that if a certain cap would have made a sound difference, he would have used it. Period.
I believe it actually stems from the tube amp world where they are used as coupling caps and such. Supposedly the differences in dialectrics in a tube amp application make a very apparent difference.
Right, and then you went and tried it yourself with a rotary switch or a couple crocodile clips, did you?
Guys...drop the alligator clips and build a decade box. It will cost about $10 minus whatever caps you decide to use.
I have a test harness with all this stuff since 2008 or so.
Am I the only one noticing that those who vehemently deny any difference in capacitors are those who just pass what they've been told and that everybody who ever went with a test setup or proper recordings is on the side of differences being there?
Also, physics. Yes these things do not just contain pure constant capacitance. E.g.:
http://en.wikipedia.org/wiki/Dielectric_absorption
