The 'Sound' of Capacitors..

umutgokcen · Post by **umutgokcen** » 21 Feb 2010, 01:44

I second that, let's go for it

I would be happy to put aside some time for the test and record some samples if needed. I have a decent setup at home and it's always on.

MoonWatcher · Post by **MoonWatcher** » 21 Feb 2010, 02:17

mictester wrote:If we've chosen 100 nF as our test value, it should be possible to get this value in lots of differing types, but each has to be exactly 100 nF, or each position in the circuit must be fitted with capacitors with the same error in value.

This is the wonderful workaround to using the same value for all 4 slots. It should really cut down on the time spent sorting and matching.

MoonWatcher · Post by **MoonWatcher** » 21 Feb 2010, 02:22

Greg_G wrote:I agree with RnFR about the Muff too.
Really I think a pedal that doesn't smash the signal so much is going to be better for hearing caps.

Remember we don't have to use original values as it's just a test.. so if it were a Tubescreamer for example, we can substitute cap values

Why don't we go with a TS then, and decide now as to which caps for the switching? If we're running in and out buffers, it actually gives us more options than a SoS would, as well.

RnFR · Post by **RnFR** » 21 Feb 2010, 19:50

oldgravity wrote:On that note, I think it's interesting that the above clips don't show a difference between the "same" value caps, even though I'm guessing they weren't matched. That means that (to my ears) even caps of slightly different value don't sound different, let alone different dielectric type.

well, i wouldn't go that far yet. the signal isn't even amplified, there is only one cap, and it's used as filter. not exactly the same thing that was being initially proposed, unless you were referring to that goofy article in PG.

as far as the TS goes, i never really liked that circuit enough to build one, so i can't comment. i was thinking that something along the lines of the this might be a good idea.

viewtopic.php?f=19&t=1153&hilit=overdriver%E2%80%A6

it's cleaner sounding with a bit of grit, there are filter and coupling caps, and an extremely wide range of tones available. this last point might make it easier to hear some of the differences.

then again, maybe something with a higher amount of distortion might be better?

MoonWatcher · Post by **MoonWatcher** » 21 Feb 2010, 22:58

RnFR wrote:i was thinking that something along the lines of the this might be a good idea.

viewtopic.php?f=19&t=1153&hilit=overdriver%E2%80%A6

it's cleaner sounding with a bit of grit, there are filter and coupling caps, and an extremely wide range of tones available. this last point might make it easier to hear some of the differences.

then again, maybe something with a higher amount of distortion might be better?

No - I think that one could be spot on. I was actually thinking about it as a good candidate, as well, especially when trying to think of something relative to a Muff in some aspects (ample similar valued coupling caps). And without the clipping diodes to provide any clamping, there s/b even more higher order harmonics than a Muff at full gain settings.

The other issue with a (stock) TS is that everything under ~700 Hz is chopped off - not so with the Overdriver.

...And you can stuff just about any BJT's in that circuit as well.

RnFR · Post by **RnFR** » 21 Feb 2010, 23:08

glad to see we are on the same page. anyone else have any input on the overdriver?

CRBMoA · Post by **CRBMoA** » 22 Feb 2010, 00:04

At first blush, that looks great to me. A few of the links are dead, and I only spent 2-3 minutes looking (I try to pay attention to the people I live with on the weekends

), so if anyone has a working link to a verified layout we could use as a starting point, that would be good. I'd like to build one up and get familiar with it, so I can be an educated monkey!

RnFR · Post by **RnFR** » 22 Feb 2010, 01:49

here's a few versions, which i believe are correct.

download/file.php?id=4125&mode=view

the only thing is, i have had some problems with this circuit biasing correctly. if we can get it sounding right, i think it would be a good candidate. i believe there is a pcb layout at fuzzcentral. there are a couple vero layouts in the thread.

CRBMoA · Post by **CRBMoA** » 22 Feb 2010, 06:12

Cool. I need to round up a couple of trannies and normal sized pots.

The Lawrence layout has the volume pot added.

If no one suggests a better pedal in the next 24 hours, I will create an 'GLOBAL CAPACITOR SHOOTOUT' thread over in the Workbench Forum Monday evening. We can use that thread to keep track of the 'nuts and bolts' of the build, and create a signup for players that want to demo/record the pedal. We can cross link them, and keep this thread for 'Deep Thoughts' and 'Philosophising'.

I am humbled and honored that you guys took me seriously. Thanks to all of you for letting me play!

marshmellow · Post by **marshmellow** » 22 Feb 2010, 11:56

I think this is a rather bad choice for this purpose. With all the electrolytics in the signal path,
everything will be masked by their really inferior performance compared to any film capacitor.
You could change around the film caps until the end of days, you won't hear a thing due to
their strong influence on the sound compared to the tiny differences that might be there
between the different film capacitors.

I never cared for differences between film capacitors. Just the sight of a pcb full of red Wimas
as opposed to blue Epcos caps probably influences my perception more than any little change
in sound I imagine to be there due to different manufacturing.

But an electrolytic in the signal path or not, is one thing I can hear in many cases (not talking
about stompboxes exclusively).

CRBMoA · Post by **CRBMoA** » 22 Feb 2010, 17:17

Ok.

Like I said, I have no dog in the fight. And most of you are FAR more qualified than I to pick the platform circuit.

If the Colorsound OD is a bad choice, what is a good alternative?

What about a custom circuit like a LPB with a tonestack?

I'm a just throwing that out there to help the discussion. I don't want to pick the circuit, but I do want us to choose a circuit so we can talk through the cap placement and switching, because THAT, and not the ciruit, is really the crux of the issue.

cb

RnFR · Post by **RnFR** » 22 Feb 2010, 18:34

marshmellow wrote:I think this is a rather bad choice for this purpose. With all the electrolytics in the signal path,
everything will be masked by their really inferior performance compared to any film capacitor.
You could change around the film caps until the end of days, you won't hear a thing due to
their strong influence on the sound compared to the tiny differences that might be there
between the different film capacitors.

I never cared for differences between film capacitors. Just the sight of a pcb full of red Wimas
as opposed to blue Epcos caps probably influences my perception more than any little change
in sound I imagine to be there due to different manufacturing.

But an electrolytic in the signal path or not, is one thing I can hear in many cases (not talking
about stompboxes exclusively).

dude, you are totally missing the point here. we are going to replace all of the caps in the signal path for .1uF caps of different types, and then do the test.

btw, we could probably include the TC caps in the test if we monkey with the values a bit. we could replace the .01uF caps in the TC for .02 which i believe you can get in elytics.

CRBMoA · Post by **CRBMoA** » 23 Feb 2010, 00:33

I suppose the fact that neither one of my DMMs measures capacitance is gonna be a problem.

Would it be possible for some of the participants to hand pick the caps and send them to me?

I guess if I need to buy a new DMM I can. I can't believe it never occurred to me.

RnFR · Post by **RnFR** » 23 Feb 2010, 01:32

i'm sure we can figure something out. you really should be able to measure your caps though! i think you can build a capacitance meter too, if you want to go that route. just search google.

marshmellow · Post by **marshmellow** » 23 Feb 2010, 10:49

Oh well, I really did overlook that. Still, with all the filters in the circuit way off with those wrong values,
I wonder how much you will be able to tell. Anyway, go ahead and have fun!

I knew I shouldn't have participated in a thread about the sound of capacitors in the first place

.

SpencerPedals · Post by **SpencerPedals** » 23 Feb 2010, 14:47

RnFR wrote:i'm sure we can figure something out. you really should be able to measure your caps though! i think you can build a capacitance meter too, if you want to go that route. just search google.

Agreed. It's what makes a test like this difficult. You have to find two that are exactly the same, within tolerances of measuring, or the entire test can be written off by "it was the capacitance that affected the sound". It's already done a lot with transistors and gain. Numbers people state that if transistors sound different, it's the gain causing it. Which is partly true, but doesn't account for having used two different transistors of the same gain that sound noticeably different. The same sort of logic should be used in a test like this, imo.

CRBMoA · Post by **CRBMoA** » 23 Feb 2010, 15:17

OK - You guys pick the circuit. I will spend the next day or so learning to build a capacitance meter.

CRBMoA · Post by **CRBMoA** » 23 Feb 2010, 16:51

Forgive the double-post, but if there is a way to edit my posts, I'm not seeing it.

There are several schems and layouts for DIY capacitance meters. I will eventually build one, but it occurs to me that using a meter I built will introduce a variable that will later be used to condemn our test and our methods. That would be tragic. Let's do this well, so the results can stand scrutiny.

Will one or two of you volunteer to measure the actual caps to be used in our 'Buzy Box'?

IvIark · Post by **IvIark** » 23 Feb 2010, 18:03

Yes, i'll measure, log and photograph the caps to keep everyone happy, and send what you need.

CRBMoA · Post by **CRBMoA** » 23 Feb 2010, 18:12

IvIark wrote:Yes, i'll measure, log and photograph the caps to keep everyone happy, and send what you need.

Thanks!