Re: Vitamin Q 0.022
A couple things; as noted, this only tests whether the difference is perceptible (which admittedly is all that really matters), and not whether there is a true electrical difference. Audiophiles like to believe they hear better than the average person, and I'd agree that you do hear more when you are aware of what you're listening for and hear it often, as with wine tasting. So if there is in fact an electrical difference, and an audiophile claims they do hear it, it's hard to prove they can't, unless we discover the differences occur at 30kHz, then we can say, "sorry friend, you don't hear that."
For the purposes of this conversation though, and for the purposes of whether or not spending money on expensive capacitors has any effect, we don't need to be able to explain it. We just need to be able to prove it exists. If I say "I'm buying these $150 capacitors, and I have scientifically valid evidence that I can detect when these capacitors are used", then it's completely irrelevant whether that difference shows up on a graph or oscilloscope. You can't look at your graph and then tell someone that they can't hear a difference, if they've just shown
in a scientifically acceptable way that they can (ie, it's a not a case of them just insisting that they can).
The other thing is that I'd expect the test subjects to actually play the guitar in case it difference is one of input response. Like with pickups, often the difference is more felt than heard, because only the person plucking the guitar is aware of difference in how his interaction with the guitar relates to what is being heard.
Yes, definitely, that was supposed to come through in my description of the experiment.
YouTube A/B videos are completely useless, simply because they're about as far from that experiment you can get: you're not playing the guitar, you're not in the room with the guitar, the sound is compressed, they tell you which capacitor is which, and so on.
Of course you will hear a difference between two different values because the roll-off frequency is different between the two. The .047uf cap has a lower roll-off which shunts more highs to ground thus making the sound darker. Using .033uf vs .022uf is a matter of taste as to whether the player likes a darker roll-off or not.
Yes, but I think we're driving at the same point here: if there's a difference in what gets "lost" to ground, then there's a difference in what gets left behind, too. So if PIO vs ceramic
does have an effect on exactly what is going to ground, then it also must have an effect on what doesn't.
I admit, I like the Sprague Orange Drops simply because they are easy to work with, I can read the values easily, and they're plenty cheap too. In the past I've used the Radio Shack green chicklet poly film caps and recently found another local source of caps on the cheap in bulk.
I like the orange drops for the same reasons: you can look at them to see what value they are, and they're nice and big and easy to work with. However, I quite often don't use them because I do object to how much UK retailers sell them for. We're talking 5-10 times the price of Maplin (our equivalent of Radio Shack, but they do still do a wide range of good quality components for hobbyists) would charge.
I use them when I do wiring for other people because if that person opens the guitar up, they look cool, sturdy etc. But most of the time, for my own personal wiring, I end up using resin-dipped ceramic capacitors. They're blue! I've also used polyester layer capacitors in PCB format, mounted on stripboard, for example in this Tele where there is a tone cap, and then a volume treble bleed kit, all mounted on the little bit of stripboard between the pots (click for larger image):
