Do capacitors sound different?

[Willabe]

I thought I'd break this of from a thread so as not to hi-jack it.

HBP posted a link to a interesting electronics Hi-Fi(?) magazine on testing for distortion in caps.

http://www.scribd.com/doc/2610442/Capacitor-Sound

I read it and asked HBP if he would care to boil it down a little. His response;

"If a cap was an ideal device and introduced zero distortion, it would have no "sound" and all caps with identical ratings would be interchangeable.

Except that almost all caps measured had at least some distortion, which seemed to follow these rules:

• The bigger the cap, the less distortion (relates to different dielectrics and construction styles), except
• Sometimes caps of a specific dielectric distort much more/less than other of the same dielectric (ceramic was notable when 2 different types exhibited the most, and almost the least, distortion of all caps tested
• Bias (voltage) across the cap increases its measured distortion (which is bad because we use caps specifically in places where there will be d.c. across them)
• Higher voltage caps seem to exhibit less distortion than lower voltage caps of the same type (which also amounts to them being bigger), and
• The rules don't always hold up (and there are bad apples even among normally-good types) so you should measure the specific caps you want to use to see how they really perform."

So if you hear a sound change when swapping caps, you're really hearing the difference in the artifacts each cap overlays on the intended signal."

Then Jojokeo asked;

"Great breakdown of the info HBP. Thank you.
But (sorry can't read it now) does it mention anything regarding caps "breaking in" or becoming accustomed to certain voltages being placed on them to where the dielectrics sort of "form" or "settle-in" similar to e-lytics?
2nd - Does it mention anything regarding outside foil direction/placement and the related characteristics or phenomena this may have?"

Here's some from my Bread Board thread on my testing different caps for tone;

Even though this is a BB, I wanted to change the K bypass cap and the plate coupling cap (CC) very fast to really hear the difference in real time and not from my ear's memory. I want to take out any second guessing.

To me this was very important especially for the CC's. I bought several different brands to see IF/how much different they might sound. 

So, for the 1st preamp gain stage, I made up a couple of brackets from some parts I had laying around to mount a couple of rotary switches. They both are movable so I can use them on other gain stages too. I did test and mark the outside foil on the CC's. (They don't look real pretty but they work fine.) 

For the K bypass caps I used a 2P6T rotary set up like this;

Position's;
1. Open/No bypass cap.
2. 0.68uF.
3. 2.2uF.
4. 4.7uF.
5. 10uF.
6. 26uF.

For the plate CC I used a 1P8T rotary (I had this here, bought it from Weber years ago, BIG honkin rotary   ) I measured each cap for capacitance and I went through the Mallory 150's I had on hand and found a yellow (old) and white (new) that were both 22.02nF. All the other cap brands I had at lest 2 each and measured for the closest to 22.00nF. Rotary switch set up like this;

Position's;

1. Mallory 150/white/630v/22.02nF.
2. Mallory 150/yellow/630v/22.02nF.
3. Jupiter/yellow/600v/20.39nF.
4. Jupiter/red/600v/19.28nF.
5. SoZo/blue/400v/22.02nF.
6. Musicap/600v/23.00nF.
7. AuriCap XO/600v/20.78
8. Mojo Mustard/630v/22.05nF.

I didn't have room for the OD 225 and 715. I also don't have a SoZo mustard, I'll test those later.

[Willabe]

And;

"Well, I changed out that coupling cap (CC) 1P8T rotary switch (RS) that was giving me problems with the new Alpha 1P12T RS, it's working GREAT! Very smooth and very fast. Play something and reach with my left hand for the switch and then play the same thing, very easy to hear any change in tone.   

I also added the 2 OD caps I had, 1@ 715/400v, 1@ 225/400v.

I played another hour or so and I am hearing some differences BUT NOTHING where I can say this cap is the best hands down.

Tests were done with the set up in reply #93, I had my Fender stand alone Reverb feeding the Champ 5F1 (with a Fender single knob tone control engaged). All test's this round were with the volume set at ~11:00, tone set at ~2:00, no change in those settings;

1. One of the differences I'm hearing is the overall frequency response across the full frequency spectrum. Some had less bottom bass end, so they sounded more bright. BUT at the same time, the brighter caps had less bottom end distortion.

2. Second difference I'm hearing is depth/3D sound. Some sound more flat/lifeless, not frequency so much but depth, more like adding a slight amount of reverb.

3. The 3rd thing I'm hearing is some seem to sound better with single notes and some seem to sound better with cords when left to sustain/ring out. There's a smoother sustained 'grind' and a very nice 'swirl' that sounds real good to me. Sounds like a big amp, Marshall/HiWatt, that's not over the top with a fuzz before it or on 10. Real nice for some things.

I only did all these test with only 1 guitar so far (re-issue 80's rosewood fret board Strat, stock PUPs, neck PUP, volume/tone full up).

As I said this is with 1 guitar/PUP's and no change in the amps/guitars  volume/tone controls.

So...... so far I think that for the same reasons that I might reject some of the caps, I believe others would love those same caps.    "
 

[Willabe]

And;

"Here's the caps I tried, uF value tested before soldering them up to an Alpha 1P12T rotary switch so I could compair them instantly and not from ear memory; 

1. Mallory 150/white/630v/22.02nF.
2. Mallory 150/yellow/630v/22.02nF.
3. Jupiter/yellow/600v/20.39nF.
4. Jupiter/red/600v/19.28nF.
5. SoZo/blue/400v/22.02nF.
6. Musicap/600v/23.00nF.
7. AuriCap XO/600v/20.78
8. Mojo Mustard/630v/22.05nF.
9. Orange Drop/400v/22.74nF.
10. OD 715/400v/22.30nF

Here's what I think so far after 3 different rounds of playing on 3 different days, playing single notes and full chords, both with -FB and without -FB;

1st, I think ALL the caps would definitely work fine for different people, in different builds, with different guitars, different PUP's and different music/playing styles. (Remember I'm testing these caps in a SE Champ, 5F1, 1x6V6, V1a/b ~150dcv plate, 6V6 ~360dcv and the 12T CC rotary switch is connected to the 1st CC from V1a plate to V1b volume control, with a Strat. And I only tested 1 of each as a sample.)

Also, and I don't know what it means, was when I tested for the caps outside foil lead, some were way noisier than others. (I mean how noisy the cap is with the outside foil lead hooked up to the test amps input.) The Mallory's were the nosiest with the white being the worst. The Musicap and AuriCap were by far the quietest. The quite 1's had very little difference in noise when flipping the switch to flip the caps leads. And on the outside foil cap lead to the test amps input they were way quieter than the other caps on their outside foil lead. Big difference.

I was thinking, before these tests, that the fatter the cap the more shielding it would have from outside foil lead to the inside foil lead. So larger values/larger voltage rating(fatter cap) would have more difference when switching leads. A 0.1uF cap is way easier to hear a difference than a .0047uF cap, I have a very hard time hearing any difference in leads on a Mallory white 150. (I know that Tubenit and Gezzer have posted they hear the opposite.  )  But the Musicap was the quietest and is the thinnest.   

So far, for the sound I'm wanting, my least liked sounding cap (to me) is the white Mallory 150. Flat , no/not much depth(3D depth) and thinner/less bottom end, yet clean(er) sounding and a little more forward/aggressive sounding? And the yellow Mallory's 150 sounds different than the white. It's fuller and has some better depth to it. But is not as clean on the bottom, because it has more bottom extended range? 

(I noticed that the shape and size/dimensions changed on the 22nF 150's but not on the other values I have of the 150's. The yellows are just a little shorter and fatter. I'm gonna have to try a few other white/yellow 150 values and see if they sound closer to the same rather than different on the bottom end.)

(I have a couple of old Fender blue tubular caps from the BF amps around here somewhere. I'll see if I can find them then test them to make sure there not leaking any dcv. Might be a good base line?)

The Musicap was/is the most balanced to my ear, top/middle/bottom end, very nice sounding, maybe the nicest mid range, had the most 3D depth of sound, smoothest distortion and had the best ringing sustain smooth growl/swrill on a full cord left to ring out. I think it has/lets the most harmonics through?  It's also, unfortunately, the most expensive. 

AuriCap was very good too, although a little cleaner/less bottom end but clearer because of it?
 
The blue SoZo, another pricey(er) cap, sounded pretty thin to me and pretty flat sounding too. But again very clean/clear sounding. (Might sound great with a big Jazz box guitar?) 

The Jupiters sounded good, pricey(er) caps, the yellow sounds pretty good, fuller and some/more depth than most. But the red costs more than the yellow, red has a tube/sleeve it's in and they sound close but less bottom and cleaner/clearer.

I can hear why Tubenit likes the OD 225's. They sound more like/close to the yellow 150 and yellow Jupiter caps. Fuller bottom, more depth, nice mids, a little less bottom that the yellow 150 and yellow Jupiter. (Might be that the mids are a little more apparent because there's a little less low end?) The OD 715 is cleaner and brighter with less bottom end distortion. For a cleaner amp, maybe for a Jazz player with a big body git box, they might sound very good?

Mojo Mustard was good, maybe a good in between cap from a bright to bassy(er) cap? I like it."

[Willabe]

And;

"I just was playing for ~hour or so with the same set up as noted before. I don't know why but some days I hear a bigger difference then other days. And the differences are definitely more pronounced on some days. 

I've been thinking about this and I thought maybe it has to do with the Champs volume/single tone knob settings?

Not how loud dB wise, I can hear the amp/speaker just fine volume wise.

But I'm thinking that distortion is having an effect in hearing any differences in the different caps? I'm going to go with the word artifacts because there are extra bits/harmonics I'm hearing? I'm wondering if you have to push the cap enough to make these artifacts heard? Going past the caps linear range? That's when I hear them more clearly?  I'm going to move the CC rotary switch to V1b's CC and see if that position in the circuit pushes the CC's a little more?   
 
Also if having V1b's K bypass cap, 10uF, in or out, I have it on a 1P1T switch.

So I tried it at different volumes and different tone settings with V1b's K bypass cap in and out. It did make more of a difference.

I'm hearing the most difference, most artifacts, on the B/G/D/A strings with the amps volume up ~50% and the tone control up to ~2:00 with V1b's K bypass cap in the circuit. Cords and double stops on those strings are the easiest to hear the differences/artifacts/the extra bits/harmonics?

There's a 'grind' and a 'depth' on cords and double stops on these strings and settings that I'm hearing. It's more pronounced with some caps then others AND I hear it in different parts of the frequency range."

"I also added 3 new caps to the 1P12T rotary switch that changes the coupling caps going from V1a to V1b.

I bought them from Angela Instruments ~ $14 each. Their Fender brand caps, 660v/5%;

Red; measured; 21.48nF; Kraft paper/Tin foil/Resin. (Red Astron/early tweeds) Sounded the fattest/warmest/full range break up.

Yellow; measured; 20.22nF; KP/Tin/Wax. (Yellow Astron/late tweeds/some brown face amps) Sounded not as fat but had the most 'hair' in the upper mid to treble. Pronounced picking attack, clicky sounding. 

Blue; measured; 22.22nF; Mylar/Tin/Wax (Blue Astron/BF amps) Sounded the brightest and cleanest, least amount of 'hair'."

[Willabe]

HBP, Thanks for your answer but do you see any link between what I'm hearing and the 2nd and 3rd harmonic distortion in the authors test's?   

That's what I was looking for in it. 

He also talked a little bit a few times about inter modulation distortion. How is that different in what I'm hearing than 2nd/3rd harmonic distortion?   

[HotBluePlates]

HBP, Thanks for your answer but do you see any link between what I'm hearing and the 2nd and 3rd harmonic distortion in the authors test's?

2nd, 3rd and sometimes many higher-order harmonics...

Investigate the Harmonic Series. Compared to a tone, the 2nd harmonic is an octave higher, the 4th harmonic is 2 octaves higher, the 6th harmonic is 2 octaves and a fifth higher, and the 8th harmonic is 3 octaves higher. All of these are fairly consonant with the original tone and explain why lower-order even harmonics are considered benign.

For the odd harmonics, the 3rd harmonic is an octave and a fifth, the 5th harmonic is an octave and a major 3rd, the 7th harmonic is 2 octaves and an out-of-tune flat-7th, and the 9th harmonic is 3 octaves and a 2nd (or 2 octaves & a 9th, however you prefer to look at it). Odd order harmonics (and all higher-order harmonics) are generally considered to add "bite" to a sound, and in large amounts could sound "grating".

As for your results: all caps you tested except the Musicap, Auricap and OD 715 are polyester dielectric; the caps I mentioned are polypropylene dielectric, with the expectation they'd perform better (sound cleaner in this case).

As for results? We'd expect any cap that sounded "warm" to have more even harmonic distortion and/or distortion products that skew towards the lower-order harmonics being louder. We'd expect that caps that sounded "bright" to either have more odd harmonic distortion (than even), higher-order harmonics, or even a cleaner sound that didn't have excessive low-order distortion. However, we can't know any of these guesses are correct without duplicating the article author's test rig, but adding a bias voltage for testing that simulates the preceding tube's plate voltage. The author didn't test with bias voltages greater than 100v because he was using a bunch of batteries as his source of d.c. voltage (to eliminate that as a variable).

He also talked a little bit a few times about inter modulation distortion. How is that different in what I'm hearing than 2nd/3rd harmonic distortion?

Harmonic distortion is musically related to the original single tone, and is always a higher frequency.

Intermodulation is when two tones are passed through a non-linear impedance (often a distorting active stage, like a tube); the output of the non-linear medium is made up of the two original tones, plus 2 new frequencies: the mathematical sum and difference of the two frequencies. So 100Hz and 1kHz would have IM products of 900Hz, 1.1kHz, as well as the original tones of 100Hz and 1kHz. The new tones are almost guaranteed to not be musically related to the original tones. Also, IM can be a source of subharmonics below the original notes, since one of the products is the difference between the tones.

Not only do the 2 original tones create 2 new tones, but any distortion of the original tone also interacts with the tones passed through the nonlinear impedance. Things become a mess real fast.

You may not have noticed, but the author used 1kHz for the bulk of distortion testing, then switch to 100Hz and 1kHz for IM testing, but still displayed only frequencies above 1kHz for his distortion plots. When there was THD of the single 1kHz tone, you saw peaks at 2kHz (2nd harmonic), 3kHz (3rd harmonic), 4kHz, 5kHz, 6kHz, etc. When he did IM testing, IM distortion showed up mostly as "pickets" 100hZ to either side of a harmonic distortion frequency. So there was a little peak at 1.9kHz and 2.1kHz (IM centered around the 2nd harmonic, with 100Hz sum/difference frequencies), 2.9kHz and 3.1kHz (IM centered around the 3rd harmonic), etc.

So IM distortion is always considered to be the greatest evil, because all sorts of non-musical trash winds up in your sound.

We can guess that "clean sound" could be a lack of distortion, or that "edgy/biting sound" could be odd-order or IM distortion, but we really don't know without doing some testing. And note the author was trying to use statistically-relevant sample sizes in his tests (like running all tests, under all conditions, on 20-30 caps of a single brand/type to verify the results were a bad cap or bad batch).

[HotBluePlates]

Eventually I'll get my test-cap rig completed and do some listening myself.

So far the candidate caps are as follows:

• Mallory (CDE) M150 (metalized polyester)
• Fender Red (Kraft paper/Tin foil/Wax)
• CDE 418P (polyester film/foil; successor to OD 225P)
• Solen MKP-FC/PPM (metalized polypropylene)
• Auricap XO (metalized polypropylene)
• CDE 715P (polypropylene film/foil)
• Musicap (polypropylene film/foil)
• K42Y-2 (small green paper in oil)
• K40Y-9 (larger silver paper in oil)
• K75-12 (hybrid paper/PET (polyester) in oil)
• KSG-2 (Mica) or SSG-1 (mica)
• FT-2 (Teflon) or FT-3 (Teflon)

Where there's an "or" it's because some types don't offer certain values, and a substitution for the closest type with the specified dielectric/construction was made.

Everything after the Musicap is a Russian cap type. I'm mounting these thing inside a former GR decade resistor box, and the mica & teflon caps are rather huge & heavy. So I'll have to secure those to the box itselfas the switch alone can't support them. Even some of the oil types are quite heavy for their size... So that's slowing assembly down a bit.

[HotBluePlates]

So I tried it at different volumes and different tone settings with V1b's K bypass cap in and out. It did make more of a difference.

I'm hearing the most difference, most artifacts, on the B/G/D/A strings with the amps volume up ~50% and the tone control up to ~2:00 with V1b's K bypass cap in the circuit. Cords and double stops on those strings are the easiest to hear the differences/artifacts/the extra bits/harmonics?

This seems to jive with what the author wrote. Higher signal levels resulted in more distortion in his tests, for caps that distorted. That seems to correspond with you having the cathode bypass cap engaged, because that's higher signal level at the plate output.

Noticing differences with cords/doublestops is probably both cap distortion and/or IM products being more noticeable.

[tubenit]

Brad and Brian,

When this thread is done .......... can one of you edit it and place it into ARCHIVES.  Good info here.

With respect, Tubenit

[dmp]

HBP - in your summary, did "bigger" mean physical size, voltage rating, uF???

[jjasilli]

Great thead!


@DMP:  for caps, bigger in voltage, or uF, basically means bigger in size.  Caps are analog devices.  Note: this is true within cap types.  E.g., a ceramic cap of a certain value may be smaller than a poly cap of that value.  But at some point a larger value ceramic cap must be physically bigger than a smaller value ceramic cap, etc., etc.


@ all:  to get a verifiable tone comparison would require double blind tests, preferably taken over several sessions, and using multiple participants. 

[Willabe]

@ all:  to get a verifiable tone comparison would require double blind tests, preferably taken over several sessions, and using multiple participants.

I agree, come on over. 

[jojokeo]

Brad and Brian,

When this thread is done .......... can one of you edit it and place it into ARCHIVES.  Good info here.

+1 very cool of you guys to do this and post such detailed info. At some point, even though you listed the caps very well, could you post photos of the caps please? Thinking this will also help a lot since our memories are "picture generated" i.e. photographic and also to help verify things and help eliminate possible confusion?
 
ps - I'm surprised with your results of the yellow vs white Mallory 150s. I thought these were supposed to be the same when they only supposedly changed colors a few years ago?

[Willabe]

I'm not sure on that, it may be just that .02 value?

I have a lot of different values of the yellow and white Mallory 150's and they all are the same size except for the .02 value. It might just be that value or a bad apple?

I have not tried multiple samples of the same cap.      

[Willabe]

Brad and Brian,

When this thread is done .......... can one of you edit it and place it into ARCHIVES. 

Sure we can do that. 

[jjasilli]

And;

"I just was playing for ~hour or so with the same set up as noted before. I don't know why but some days I hear a bigger difference then other days. And the differences are definitely more pronounced on some days. 

I've been thinking about this and I thought maybe it has to do with the Champs volume/single tone knob settings?

@ all:  to get a verifiable tone comparison would require double blind tests, preferably taken over several sessions, and using multiple participants.

I agree, come on over. 

Ok, where are you!?!


Maybe a spouse, friend, bandmate whatever could work the rotary SW, and keep a record of that; while you keep a record of your tonal impressions.  No peeking or cross-talk between the SW operator and the listener.  Double blinding is a big project, but might be worth it considering how much work you're doing anyway. 

[PRR]

I've been asked to stop in.

I'm quite agnostic about cap "sound". Most good caps sound the same to me. Certainly so now that I have lost much hearing.

[bnwitt]

I've been asked to stop in.

I'm quite agnostic about cap "sound". Most good caps sound the same to me. Certainly so now that I have lost much hearing.

You and me both brother.

[uki]

This is a very good test database Willabe!

I didn't have the chance to test as much not even on guitars which are my real field of operation, and I don't have that many different types of caps to do so, only thing that I've tried is different values which does really change the depth of the tone control. On guitars I haven't noticed any difference with different types of caps.

Now on amps, that is a completely different field. Some caps may not have any audible difference but some might be noticeable right the way as you have tested.

Here a interesting video of the same sort of test on a guitar tone control:
https://www.youtube.com/watch?v=92G-jw4TqS4

[HotBluePlates]

HBP - in your summary, did "bigger" mean physical size, voltage rating, uF???

Yes. 

You need to understand something about how capacitance works. In general, a cap's capacitance goes up when the plates of the cap are moved closer together, or if the area of the plates (and their overlap) is made larger. There's also a fudge factor which accounts for the insulator between the plates; different insulators generally increase the capacitance of a given capacitor compared to using air (space between the plates) as the insulator.

But every insulator has a breakdown voltage; if you need a higher voltage rating with a given insulating material, you might need more of it between the plates, and then make the plates larger. So the cap gets bigger 2 ways there.

There's a battle between ideal insulating material and how huge a cap of a given Farad-rating gets with that insulator. You're not gonna see caps above 10's- to maybe 100-pF which are insulated by air between the plates. If you put a good piece of plastic between the plates, you can move them much closer together for the same voltage rating. Except now maybe that plastic absorbs more electrons than plain air. Capacitance went up for a given size and/or the size got much smaller for a given capacitance & voltage rating.

I mention all this because the author's tests generally note lesser distortion for higher-voltage-rated caps (IIRC). But then he also noted less distortion for film/foil type caps than for metallized caps with the same dielectric.

You can roll up a cap with alternating pieces of aluminum foil & polyester. The mating surfaces of the materials won't be in perfect contact everywhere, so the resulting cap is bigger than it might otherwise be. Metallization is sputtering vaporized metal onto a plastic film to form a conductive surface (which the author notes is still thin enough to see through). Doing this, you dramatically decrease the size of the cap for the same value, voltage rating & dielectric. Note how a metallized polyester Mallory 150 is much smaller than a film & foil polyester orange drop 225P/418P.

Except that C0G ceramic caps don't seem to be huge for a given rating, and they had almost the lowest distortion of any cap tested (but other general-purpose and lower quality cermaics like the X7R were absolutely horrible).

[HotBluePlates]

Here a interesting video of the same sort of test on a guitar tone control:

I watched his 2 videos and didn't like the test approach.

He starts off intending to test different dielectrics, but all caps except one are polyester. There are, however, construction difference which relate to the size of the caps. Of course changing the value of capacitance changes the action of the tone control.

But a tone control is a lousy place to reveal the sound of a cap (signal is just being eliminated). Also, the pickup is a coil with inductance, and we're introducing a series cap in the circuit. If there are small differences in each cap's actual capacitance, this will change the sound of the pickup and the inductance resonates with the changed capacitance a little differently than the previous cap, which changes the pickup's sound. So there are explainable reasons for tonal changes if everything is not otherwise identical.

All that said, I'm not shooting for perfectly identical capacitances in my test setup, mainly because I can't afford to buy many of each cap type to get exactly-matching capacitance values. Also, some caps (due to dielectric material and size) only came in certain value and/or voltage ratings, meaning I have to put caps in series or parallel to get the right composite cap value/rating. And I had cases where 0.05uF was available for a certain cap type, but the 0.047uF value of other types cannot be exactly duplicated. Etc, etc.

But in the end, I'll probably listen to the caps taking the place of a coupling cap in a simple Valve Jr circuit (but through much better speakers than the on-board Eminence). Either I'll hear a "Wow!!" difference or not, and it should be pretty easy to account for a tiny bit more bass in a 0.05uF cap over a 0.047uF cap (if it's even audible).

[uki]

a tone control is a lousy place to reveal the sound of a cap (signal is just being eliminated).

I agree about his approach not been the best, it doesn't change the tone while spinning the tone control, just the depth of the tone as the value changes. I understand in amps it will do make a lot more difference.

....... bit more bass in a 0.05uF cap over a 0.047uF cap (if it's even audible).

Oh I did like this note about more bass, I don't like too bright sound, so if those initial input caps in an amp are swapped for lets say, .056 or .06 or .068 so there will be a little more bass, which caps would be key in setting the overall tone in an tube amp?

[Willabe]

Willabe and HBP,

I'd love a best guess on this........ Do you think IF I replace 4 of these caps with Musicaps that there would likely be a noticeable to significant difference in tone on the clean channel?

My guess is it will.

Ken Fisher years back suggested to change just the 2 blue molded coupling caps to PP caps for the PI in BF amps. Gerald Weber picked up on it and many of the amps he built to sell had Malory 150's for the pre and PP's for the PI.

I have a Champ 5F1 set up on the BB to do my cap testing, so only 2 coupling caps. I have the 12T rotary switch set up for the 1st coupling cap going from V1a to V1b.

I'm going to add a 2nd 12T rotary switch for the 2nd coupling cap, going from V1b to the 6V6, and see if it makes a bigger, more noticeable change in tone. I'm thinking it will.

I need to go down in my basement and find a couple more of the brackets I used for the rotary switch. I've already bought a few more of the caps I need to do this.

[Willabe]

Maybe a spouse, friend, bandmate whatever could work the rotary SW, and keep a record of that; while you keep a record of your tonal impressions.  No peeking or cross-talk between the SW operator and the listener.  Double blinding is a big project, but might be worth it considering how much work you're doing anyway.

I'm trying to get 3 of the guitar players from church together to do this. But 1's studying for his collage finials and the other 2 have families/young kids. So, it will be a while.

[HotBluePlates]

I'd love a best guess on this. This 5879 OD version of my  D'Mars has mostly Orange Drop PS series. Forget the OD channel for a minute and think of this as just the clean channel into the LTPI and power amp.

Do you think IF I replace 4 of these caps with Musicaps that there would likely be a noticeable to significant difference in tone on the clean channel?

I have no idea. 

That's why I'm building the box the way I am: Selector switch which sets 0.022uF, 0.047uF or 0.1uF as the active range being used, then 12-pole switch for that range to pick which of the caps I listed as the in-circuit cap. Then listen to see how it sounds.

Maybe the cap has a sound, maybe it doesn't (I'm building what I am to hear for myself). Notice Willabe said, "I played another hour or so and I am hearing some differences BUT NOTHING where I can say this cap is the best hands down." Any difference might be very small. Maybe a cap type has an impact one place in the circuit but not in another. For me it's too expensive to buy some of these and not know whether the cost is justified. Also, some types are physically HUGE (see below) and require advance planning to use, as well as being expensive; it seems prudent to know up-front whether they're worth the trouble & expense.

... At some point, even though you listed the caps very well, could you post photos of the caps please? ...

Ask and ye might receive... 

Caps below are left-to-right in the order I noted in my earlier post.

Maybe a spouse, friend, bandmate whatever could work the rotary SW, and keep a record of that; while you keep a record of your tonal impressions.  No peeking or cross-talk between the SW operator and the listener.  Double blinding is a big project, but might be worth it considering how much work you're doing anyway.

Agreed double-blind is the way to go. Then again, so is playing a pre-recorded passage through the amp to rule out playing variations. I doubt I'll be able to arrange such, and will have to consider "wanting to hear a difference" in the results.


"What I'd like to hear" from testing: large, clear differences between caps to justify selecting one over another in an amp.


"What I expect to hear" from testing: A difference, if any, that's slight and could be overwhelmed by a tone control setting change.

[Willabe]

Except that C0G ceramic caps don't seem to be huge for a given rating, and they had almost the lowest distortion of any cap tested (but other general-purpose and lower quality cermaics like the X7R were absolutely horrible).

Ok, how do we know which is which if/when we buy some? And are silver mica caps a 3rd type?   

[Willabe]

it doesn't change the tone while spinning the tone control, just the depth of the tone as the value changes.

Well yes it does, it rolls off the hi end. Changing values is a different thing.

Oh I did like this note about more bass, I don't like too bright sound, so if those initial input caps in an amp are swapped for lets say, .056 or .06 or .068 so there will be a little more bass, which caps would be key in setting the overall tone in an tube amp?

Any of the coupling caps, maybe you might hear more of a difference changing the 1st coupling cap. 

As far as going from .056 to .06 or .068 using the same brand/type of cap that's not much of a change.

Either I'll hear a "Wow!!" difference or not, and it should be pretty easy to account for a tiny bit more bass in a 0.05uF cap over a 0.047uF cap (if it's even audible).

[Willabe]

But a tone control is a lousy place to reveal the sound of a cap (signal is just being eliminated). Also, the pickup is a coil with inductance, and we're introducing a series cap in the circuit. If there are small differences in each cap's actual capacitance, this will change the sound of the pickup and the inductance resonates with the changed capacitance a little differently than the previous cap, which changes the pickup's sound. So there are explainable reasons for tonal changes if everything is not otherwise identical.

Ken Fisher used this to back saying that changing the tone cap in a guitar will change the tone. Said it was like how a wha wha pedal works. He went as far as to say certain caps won't let you roll off the tone to get 'women tone' like Clapton or Lesli West.   

[HotBluePlates]

Except that C0G ceramic caps don't seem to be huge for a given rating, and they had almost the lowest distortion of any cap tested (but other general-purpose and lower quality cermaics like the X7R were absolutely horrible).

Ok, how do we know which is which if/when we buy some?

Buy them from a reputable seller which identifies the type (and/or temperature coefficient, often +/-30ppm for C0G). Look at a cap data sheet and know the markings for that brand which indicates C0G (which might mean looking for tolerance, as it seems only C0G caps are rated for very tight tolerances of 5% and less).

And are silver mica caps a 3rd type?   

Yep, mica is not ceramic.

[HotBluePlates]

Ken Fisher used this to back saying that changing the tone cap in a guitar will change the tone. Said it was like how a wha wha pedal works. He went as far as to say certain caps won't let you roll off the tone to get 'women tone' like Clapton or Lesli West.

Listen for yourself, just changing the cap values and not type.

https://www.youtube.com/watch?v=8t_eqST1pWQ

[Willabe]

Sorry, I should have been clearer, he (Fisher) was talking about type/brand not value.

[Willabe]

Maybe the cap has a sound, maybe it doesn't (I'm building what I am to hear for myself). Notice Willabe said, "I played another hour or so and I am hearing some differences BUT NOTHING where I can say this cap is the best hands down." Any difference might be very small. Maybe a cap type has an impact one place in the circuit but not in another. For me it's too expensive to buy some of these and not know whether the cost is justified. Also, some types are physically HUGE (see below) and require advance planning to use, as well as being expensive; it seems prudent to know up-front whether they're worth the trouble & expense.

Agreed double-blind is the way to go. Then again, so is playing a pre-recorded passage through the amp to rule out playing variations. I doubt I'll be able to arrange such, and will have to consider "wanting to hear a difference" in the results.


"What I'd like to hear" from testing: large, clear differences between caps to justify selecting one over another in an amp.


"What I expect to hear" from testing: A difference, if any, that's slight and could be overwhelmed by a tone control setting change.

I found this to be true to some extent. Re- adjusting the controls for each cap especially the tone knob did alter/nullify any differences between the caps, some more than others. That's why I left the volume and amps single tone control (5E3) set the same for all tests.

But, I still think some caps were warmer sounding and had more of a 3d depth, this was harder to change by adjusting the volume and tone control. Some if not most of these artifacts/differences in tone still stayed.

Also I wonder how much I'm unconsciously changing my picking attack? I know that I do things with my picking hand all the time without thinking about it at all, after many years of playing you just do it. It's reactionary just like a baseball infielder reacting to a ground ball, instincts take over. If they have to think about it, it's to late, base hit. 

[PRR]

> You're not gonna see caps above 10's- to maybe 100-pF which are insulated by air between the plates.

AM radio tuning caps were 365p+180p air dielectric, variable.

But they were also usually the biggest part in the radio, which rather confirms your point.

And they could be troublesome with vibration.

And at some sense there are no true air caps. Air is lousy at holding the plates in position. There's always a more solid (ceramic, phenolic) dielectric support bridging the plates. The area can be much smaller than the total plate area so it does not add huge loss, but can limit the voltage breakdown and add small loss.

[HotBluePlates]

Yep, shoulda said "few-hundred pF" (which is what I really meant. The big tuning cap in a HP 200CD goes up to 617 pF/sect (more or less because you can bend the plates to fine-tune the capacitance), but it is way-huge compared to any typical coupling cap and really impractical for a guitar amp.

Those mica caps in my picture (the big brownish blocks) are big & heavy, and generally not practical to fit into a guitar amp unless you know you really, really want them and design the amp layout to accomodate them.

[Platefire]

Test results didn't sound to good for Mallory 150 whites, I've used a lot of those last couple of years. Thanks for sharing all the hard work Willabe! Platefire

[Willabe]

Test results didn't sound to good for Mallory 150 whites, I've used a lot of those last couple of years.

I'm not sure on that, it may be just that .02 value?

I have a lot of different values of the yellow and white Mallory 150's and they all are the same size except for the .02 value. It might just be that value or a bad apple?

I have not tried multiple samples of the same cap.   

[jojokeo]

It's reactionary just like a baseball infielder reacting to a ground ball, instincts take over. If they have to think about it, it's to late, base hit.

Unless maybe J Heyward is there backing up to field it & throw him out? 

[Ed_Chambley]

Guys, I know I will get booed for mentioning this.  Here is a link to ceramic caps I prefer over silver mica.  I have had problems with mica caps, especially if they are those glob looking types.  The ones like Doug has and the Cornell Brown seem to be good, but I used these in my AC15 Build and have not used anything else for small value 50pf to 1000pf.

Maybe one of the more technical guys can look at the datasheet and give a clue as to why these may perform well:
https://product.tdk.com/info/en/catalog/datasheets/leadmlcc_conventional_fk_en.pdf

And maybe explain.  I read all the time, get those ceramics out, but we all love those old amps that are just full of them.  Maybe I just like harsh tones , but I am being serious about these caps.  They are tough and the leads are nice.  It is odd the max voltage is 630 which seems low for a ceramic family.

Since we are speaking caps, I thought the ceramic could be included and if other have had good results with ceramic caps.

[jojokeo]

Ed,
I find "cap talk" difficult without a visual of exactly what we're talking about. Sorry, but I need photos of what you are not a fan of/had issues with and what you (and others) find you like or are okay? A lot of ceramic caps do no mark their voltage ratings which is something I dislike. But I'm not prejudiced about ceramics especially 1n and smaller. But IMHO the best and most stable for these values is Styrene. Unfortunately they are expensive if using higher values with the right voltage rating and they can be sensitive to people with a heavy soldering hand as they melt. But if I had my druthers, I'd be using styrene at least for the smaller values.
 
Where do you locate those caps of which you speak of???

[Ed_Chambley]

Ed,
I find "cap talk" difficult without a visual of exactly what we're talking about. Sorry, but I need photos of what you are not a fan of/had issues with and what you (and others) find you like or are okay? A lot of ceramic caps do no mark their voltage ratings which is something I dislike. But I'm not prejudiced about ceramics especially 1n and smaller. But IMHO the best and most stable for these values is Styrene. Unfortunately they are expensive if using higher values with the right voltage rating and they can be sensitive to people with a heavy soldering hand as they melt. But if I had my druthers, I'd be using styrene at least for the smaller values.
 
Where do you locate those caps of which you speak of???

The link will give you the specs.  They come from Mouser.

[PRR]

"Ceramic" covers everything from 99 cent flower-pots to race-engine pistons. They are NOT all the same.

Your link includes C0G and X7R. C0G types are "perfect". X7R is mildly flawed.

> The link will give you the specs.

Only values and sizes. This link does not explain the different formulations.

[Fresh_Start]

Guys - thanks so much for sharing these insights!

Chip

[tubenit]

OK, I ordered 3 Musicaps.  I will replace .02 V1a coupling cap and then notice IF there is any change.  Then I will also replace the post LTPI coupling caps & note the change.  And then report back. 


see reply 22 on thread


With respect, Tubenit

[Ed_Chambley]

"Ceramic" covers everything from 99 cent flower-pots to race-engine pistons. They are NOT all the same.

Your link includes C0G and X7R. C0G types are "perfect". X7R is mildly flawed.

> The link will give you the specs.

Only values and sizes. This link does not explain the different formulations.

I do not know the difference, but I first used the C0G doing the "Seeing Eye Mod" on a Boss pedal.  Robert Keeley wrote an article on modding the pedal and specified these as "class 1 ceramic" in 2 locations and as with anything shipping costs encouraged me to purchase more.  I did not know why he specified these and still do not.  I do remember the article mentioned Class 2 ceramic to not be used for audio.

I have since reading your reply found COG/NPO are multi-layer and a link: http://www.cde.com/resources/catalogs/ceramperf.pdf
I am finding there is way more information on ceramic caps than I first thought and can easily understand why it is common for some ceramic types to cause unpleasant results.  Therefore it is much easier just to stay away from them in audio.

They actually resemble a dipped cap as opposed to the circular type.

[sluckey]

I used quite a few Z5 ceramic disc caps in my AO-63 conversion project, mainly because the original was loaded with them. Some in the trem circuit, but others directly in the signal path. Should I have chosen a different cap?

[Ed_Chambley]

I used quite a few Z5 ceramic disc caps in my AO-63 conversion project, mainly because the original was loaded with them. Some in the trem circuit, but others directly in the signal path. Should I have chosen a different cap?

Only if you want to.  Since they were already in there you really didn't choose them anyway.  You never know tho, replacing them with the correct one may make it play in stereo.  Hell maybe even 7.2 and display a 4K image.

I have a lot of amps with Z5 caps and I did not even know what the difference was until they started this thread.  I think it is funny what you read on amp forums and how a LOT of people say ceramic? Bad?  Then the same person covets their original old Valco.

That is what I meant when I mentioned Robert Keeley specifying the specific type.   Who knows, maybe he knows something about modding the pedal I don't.  I do find it interesting tho, because I never really considered all the different types.

I did not keep using them because I thought they delivered a better quality of sound, I simply like the size of the leads and the pretty blue color.

I also know you you are being genuine in your question being the sensitive guy you are.

[sluckey]

I'm very sensitive Ed. But my hearing suffers. Probably too much hair growing out of them! What's with than anyway?

I depend on you guys to steer me straight on this tone stuff so please drive carefully. 

[jojokeo]

You never know tho, replacing them with the correct one may make it play in stereo.  Hell maybe even 7.2 and display a 4K image.

I have a lot of amps with Z5 caps and I did not even know what the difference was until they started this thread.  I think it is funny what you read on amp forums and how a LOT of people say ceramic? Bad?  Then the same person covets their original old Valco.

That is what I meant when I mentioned Robert Keeley specifying the specific type.   Who knows, maybe he knows something about modding the pedal I don't.  I do find it interesting tho, because I never really considered all the different types.

I did not keep using them because I thought they delivered a better quality of sound, I simply like the size of the leads and the pretty blue color.

I also know you you are being genuine in your question being the sensitive guy you are.

  Loved that Ed! And on Keeley? I don't think so. The pedal mods these guys do are practically highway robbery and the catchy name is just clever marketing preying on the innocents. BTW, if sent me his pedals I'd give him the Stink Eye mod. ;)

[jojokeo]

I'm very sensitive Ed. But my hearing suffers. Probably too much hair growing out of them! What's with than anyway?

I figure the good lord feels we need extra protection in our openings as we grow older? Especially as our wives can get shall we say a little more emboldened with us as we age?

[sluckey]

Hey, I've got a doctor's certificate that I flash occasionally when I've said "huh?" too many times. She still thinks it selective hearing loss though!