Sound differences between cap brands? Test results?

[printer2]

I just find it odd nobody can figure out a way to measure the differences between capacitors in a circuit. Either changing capacitors changes the frequency response or adds distortion. Can't think of too many other effects.

[Jazz P Bass]

Good point!
There is such a thing called "Scientific Method".
(ie: the scientific method attempts to minimize the influence of the scientist's bias on the outcome of an experiment.)
I cannot imagine going for a grant to study this phenomenon with phrases such as: "I like, sounds better".
If a difference can be heard it can be said that:
(1) the difference should be reproducible by anyone with the same setup.
(2) the facts must be backed up by some type of data.

[überfuzz]

I can definitely hear difference between caps...

Crap caps start to sound really bad when they turn to the dark side. The life span tend to be longer if you get a good cap, not tautology unfortunately. And the illusive paper in oil caps seem to be immortals. I have some friends claiming to have revive some old amplifiers with snake oil caps. I see, or better yet, hear two things. Old road worn caps have been replaced with new fresh caps. And not to be forgotten, they really believe they hear the brand, or type of cap. I think both reasons are to be taken seriously.

[guitician]

I think the sound of caps are not as big a problem then as how the listener listens to sound. And if your making music, all created sounds are valid if constructed with a tasteful ear.
I have extremely revealing stereo speakers that have me hearing parts of songs that I've grown up listening to and never noticed before. If I listened to this music through two guitar amps, those parts would have gone unnoticed. My stereo amplifier has all film/foil caps, and if I changed them all out for paper/wax, or ceramic, or paper/oil etc, I probably wouldn't be able to tell the difference in any of them. But I bet someone else could. And that they could, really doesn't matter to me.

[Chuck H]

The trouble with recorded samples, as input or reference, is that they are another source of signal distortion. So you would then need to determine the affect the mic, media and interface amps have that might mask otherwise audible differences.

Just playing devils advocate here.

I've done some tests and I really don't think it's possible to discearn between film caps of different brand or construction when only one cap is swapped. I once built two amps that were identical with the exception of using Mallory 150's in one and Vishay 715P's in the other. I could hear a difference between the two amps. BUT... If I had built both amps with the same type of capacitor I probably still would have heard a difference. All the resistors, tubes and capacitors have value tolerance. No two amps are the same. Bias points will be a little different as will pass frequencies, balance of circuits like phase inversters and attenuations from voltage dividers, etc. So it's hard, even with the two amp model, for me to commit to a difference in film caps. Anyway, the difference was so small that wouldn't merit stressing over one type or the other.

A bigger difference in cap construction comes from derate conditions. Polypropylene caps are more temperature stable than other types. So if you want your amp to sound the same on set three as it did on set one, use polypropylene.

[printer2]

I got around to hearing the sound samples from Metroamp. If you listen to the recordings in sequence it is hard to conclusively say if there is a difference or not between the caps. What I did was mark the locations on the file with the same passage and clicked between the same sections as they played. I must have bad ears as I did not hear any difference. I would say that if one piece of one recording were spliced into one of the other cap's recording I would not notice where the splice took place.

[daz]

The trouble with recorded samples, as input or reference, is that they are another source of signal distortion. So you would then need to determine the affect the mic, media and interface amps have that might mask otherwise audible differences.

Not only that, but as i have said many times and no one seems to think much about it is that a huge part of what we call tone isn't even audible. It's FEEL, DYNAMICS etc. It's IMO even more important than the thing we hear called tone. Because with a average amp thats not in the least stellar tonally, if the dynamics and feel is killer you will make up for any tonal shortcomings because you will dig in and play so much better ! The cap differences i "heard" I actually felt as much if not more than heard. I was determined to prefer the sozos hearing all the hype and paying a ton for them, and if i hadn't heard and/or felt a difference they'd still be in the amp. And if i was predisposed to hear the magic of sozos like everything i'd read seems to make them out to be, i'd have placebo'd my way to leaving them in. Instead i ordered more mallories and $hit-canned the sozos i paid stupid high $ for.

[Steve Conner]

So Daz, how did you do on identifying the different caps in those sound clips from the Metro Amps forum? You should have heard those "lead pipe upside the head" differences.

Edit: Doh! I just listened to the track and he ruins the test by telling you which caps are which. I'm going to edit the voiceover out and get back to you.

[Alex/Tubewonder]

Edit: Doh! I just listened to the track and he ruins the test by telling you which caps are which.

[DrGonz78]

Listening to the Metroamps example #1 is the best to hear a difference in my opinion. I hear the mallory caps in the first example and it has more bite with a more airy sound. The other examples in sound bite #1 sound a bit thicker in the low mids as they go through each example. I hear just a tiny difference of low mids at times in each these other examples. The mallory caps to me stand out as a totally different sounding in this example.

When in example #2 of a lead tone pushed loud it is hard to hear any difference at all. The leads all sound almost the same to me with really no distinct difference. To me when the amp is pushed it makes almost no difference at all in tone.

The more you listen to the clips the less objective your ears become and the only one I would be able to pick out of all the clips is the first one w/ mallory caps.
There is a slight difference with NOS mustard caps and another slight difference w/ NOS mustard caps w/ NOS preamp tubes at the end of example #1. That is all very subjective and I don't really feel that I care so much as listen over and over again. Actually the more I listened made me just want to find the one that is most cost effective and go with that signal cap. To me I can use EQ and other vices to make my guitar sound the way I want it to sound.

[blindboybenton]

I had a quick read while on lunch. I got to agree with Guitician, The sound/tone is a personnel thing !

Blindboybenton

[Jazz P Bass]

I don't have the time or inclination but could someone run the clips through Audacity or a similar program?
Then you can 'see' what you are 'hearing'.

[daz]

I don't have the time or inclination but could someone run the clips through Audacity or a similar program?
Then you can 'see' what you are 'hearing'.

If you can't hear/feel the difference, try this. This is the way i test ALL tweaks i do and most of the time it magnifies the difference greatly. So that if you can't tell this will often bring out the difference in spades. Everyone knows how guitar tone reacts much differently to your ear when in a live band context. What i do is crank some MP3's from many different artists and even genres and play along. I do this while the chassis is on top of my combo cab with the iron hot and if it doesn't fit in the mix and feel like it plays itself i stop the tune and go back to the previous value/circuit whatever and start the music up again. If you've never done this try it. I'm not exaggerating when i say i was floored by what this revealed when i first started doing it a few years go. Often times i will find something that is very subtle but i feel it may be a slight difference to the good. Then i will test it i the mix and be shocked to find it doesn't work at all. I also do NOT crank it up to stage level, partly because i can't here but also because at a bit less it's even harder for the tone to fit well in the mix. Probably about at what i feel is very small stage level like a small bar where you keep getting the turn it down sign.

Th thing about all this that IMO is important is this....subtle things, especially when additive via several subtle but good changes, can make what amounts to a huge improvement in your amp in how well it fits in a mix. And when it does that also tends to make it better solo too. They can sound subtle when you listen for the differences, but when you are just playing and not listening for those things, otherwise subtle things can show up by just seeming that the amp doesn't quite feel or sound the way it should and you struggle to fit in the mix and your playing goes to cr@p. You may not even know what the difference is, and thats the crux of this thread IMO......just because you can't tell doesn't mean theres not a subtle difference, and that subtle difference can result in no so subtle changes in the way the amp works with you.

[stormbringer]

So Daz, how did you do on identifying the different caps in those sound clips from the Metro Amps forum? You should have heard those "lead pipe upside the head" differences.

Edit: Doh! I just listened to the track and he ruins the test by telling you which caps are which. I'm going to edit the voiceover out and get back to you.

Later in the thread, George gives separate files for all cap clips, with generic file names so that you don't know what your are listening to.

[exclamationmark]

Edit: Doh! I just listened to the track and he ruins the test by telling you which caps are which. I'm going to edit the voiceover out and get back to you.

If you go into that metroamp thread a bit further, there are separate files for a blind test. If you open them up in any DAW, the differences in the shape of the waveform outlines can be clearly seen - though they all sounded within an inch of each other to me! Also, for some reason the vintage sozo sounded like it crapped out in the start. Perhaps maybe it was out of spec and increased the bass response a bit too much? It'd also be helpful to know how close these capacitors were in measured value too.

For me, this test really confirms my suspicions and I'll continue to use whatever film capacitors I can get my hands on.