the tone cap myth...

[Steve A.]

I have been trying out tone caps for quite a while now. I agree that there is a noticeable difference. If you guy's can find them, any of the old paper and oil caps that have the sealed glass ends are great. Vitamin Q, Good-all, Gudeman, Pyramid etc. They seem to add a vocal quality in my LP's that I can't get out of other caps...Try some and report back guy's. I'm curious to see if you get the same results. Here are some examples.

http://cgi.ebay.com/2-NOS-022-200v-S...QQcmdZViewItem

http://cgi.ebay.com/Capacitor-0-022m...713.m153.l1262

The first link is to NOS Sprague caps at $8 apiece while the second link is to ones made by Good-All at about $1.50 apiece (factoring in shipping).

I was just wondering if you have tried the Good-All caps- are they every bit as Good as they say...? [groan]

I guess that there are 10 lots of 20 caps left but I think I'd want to hear from someone who bought them before plunking down the cash. (I did get the last pair of NOS caps from the first link- thanks for the tip!) With the 100v rating of the Good-Alls its not like I could use them in tube amps but just guitars and stomp boxes...

Steve Ahola

[Mike Sulzer]

250K pot for humbuckers is wrong, Epiphone is probably trying to compensate for crappy shrill pickups. If you're doing tests between cap types a Blues Junior is not an ideal test amp. Ideally where you're going to hear the most differences is through a large stage amp with some power and clarity. The Blues Junior is cathode biased and an amp I totally avoid in testing pickups, I have one. That amp tends to make everything sound way better than it really is, I used to test pickups on it in the beginning, then when I got my '73 deluxe reverb some of my pickups sounded like crap through that, that amp really shows whats going on way better than a BJ......

The post you are referring to says the Epiphone has a Gibson pickup in the bridge position. Too shrill? There is no reason why cathode bias would hide differences between capacitors in a guitar, especially when the amp is played clean, nor is a large amp necessarily more clear. You are making the claim that the value and type of capacitor matter when the tone pot is on 10, a position that isolates the capacitor from the circuit. Try double blind testing.

[Possum]

...

The Blues Junior uses EL84 tubes cathode biased, that amp is not a clean sounding amp; compare to a vintage handwired 6L6 amp or even 6V6 and you'll hear things in your pickups you'll never hear in a Blues Junior, I have all those types of amps, the Blues Junior is a very poor test amplifier, it will take shrill, thin sounding factory wound junk and give it body and even out all its imperfections, the other amps will show the warts right out front :-) When I first started making pickups, almost 7 years ago now, I used my Blues Junior to listen to stuff, then took the products to the jam where alot bettter handwired amps were being used, and let players try my stuff. Well I got my feelings bruised when I heard what was coming out amps that the pro's were playing. I would highly advise anyone making pickups to not use that as a test amp. Now I'm not saying the Blues Junior is a bad amp, I'm just saying its not a good one to hear tiny nuances. Here is a real good example of one set of pickups through a bunch of different amplifiers, including a Blues Junior, scroll down to the PF Star set and the amp demos:
http://www.sdpickups.com/humbuckers.shtml
They all sound good, though the Victoria, which is running power tubes on 300volts, cathode biased is pretty muddy with any buckers, though these got some acceptible tones. The Blues Junior sounds good but is totally out there compared to the other amps where you hear the actual pickup's real character much better. The BJ is almost like playing through pedals or something, I like the amp but I like the Vibrolux best of all, big clear tones, crappy pickups don't sound good in that amp :-)

By common experience most of us here DO hear the difference in cap values when the tone control isn't turned back. I haven't been able to find time to post those audio clips where you can plainly hear it, especially in middle position where every tiny nuance of the pickups shows up when you make a change in parts, magnets, wind, etc. In my new set I"m working on, the middle position is one thing I pay close attention to, sometimes changing one thing in the bridge or neck isn't so apparent but in the middle position the change becomes real obvious; changing cap values shows up really clear here.

[Joe Gwinn]

Question: Do ceramic or other caps get "weird" because of how we solder them?
...
So, to close the circle here, I have noticed that sometimes when I get a little "overenthusiastic" about soldering a ceramic disc cap, that it "sweats". That is, the heat causes what I gather is wax to reflow. I'm assuming that ceramic caps are spec'd for behaviour exhibited when the consistency of the materials inside has NOT been altered.

They are, but reflowing the wax isn't going to matter. Ceramics are made at far higher temperatures, and dipped in wax at the last step.

Of course, because of the aluminum can and plastic surrounding them, I have little idea about what my soldering fervour does to electrolytics or any other type of cap whose construction does not make the consequences as easily visible as they are with ceramic disc types. One can cook electrolytrics, but it's very uncommon for ordinary soldering to do any harm.

So, my question is really "How much of the bad rapping that ceramic (and perhaps some other cap types) caps take is really a result of some of us misusing them and causing them to be off-spec?". You will note that one of the quirks of the famed bumblebee caps is that those are some BIG mothers, and likely to sink any excess heat away more effectively than thin ceramics.

I think the problem is more the subjectivity of audio, not a scourge of bad soldering.

And this "ceramics are microphonic" thing; is that in spite of installation conditions or because of them?

Ceramics are inherently microphonic. No abuse is required. The "high-K" dielectric used in ceramic disk capacitors is barium titanate, which is also used for its piezoelectric properties. http://en.wikipedia.org/wiki/Barium_titanate

[Mark Hammer]

Many thanks for that. Always nice to know what does and what doesn't matter.

[Mike Sulzer]

The Blues Junior uses EL84 tubes cathode biased,

There is nothing wrong with the sound of cathode bias. By the way, this schematic shows that the BJ is grid biased: http://www.blueguitar.org/new/schem/fender/blues_jr.gif. And another one I got off Fender's website a few years ago also shows the same grid bias, -10.7 volts.

Common shared experience means very little. You can find one group of people with a shared experience that is completely inconsistent with the shared experience of another group.

Testing of small differences needs to be double blind. Testing results that are inconsistent with physics need to be checked especially carefully.

[Steve A.]

... You are making the claim that the value and type of capacitor matter when the tone pot is on 10, a position that isolates the capacitor from the circuit. Try double blind testing.

I question your suggestion that a pot set at 10 isolates the capacitor. I have used push-pull pots to remove the tone cap from the circuit and it brightens up the sound considerably. And they do make "no load" pots for tone controls that will do the same when you turn them all of the way up.

As for the suggestion that you would not hear the difference between a 0.022uF cap and a 0.047uF cap with the tone control set to 10, I have one guitar that allows me to switch between those two values and yes, I can hear a subtle difference between the two when the tone control is set to 10. Of course the difference is much more noticeable when you turn the control down.

However, the jury may still be out on the issue of whether you can hear the difference between two different caps of the same value with the tone control dimed... I'm still waiting for the details at 11:00PM...

In any case, there would be no market for no load tone pots if a regular pot completely isolated the tone cap when set to 10.

(Is there an emoticon here for beating a dead horse? Or maybe I should add the disclaimer that no living animals were harmed in the making of this post... )

Steve Ahola

http://www.blueguitar.org/

[Steve A.]

... Ceramics are inherently microphonic. No abuse is required. The "high-K" dielectric used in ceramic disk capacitors is barium titanate, which is also used for its piezoelectric properties.

The Orange Drop caps I use also seem to be very microphonic- whenever I tap on them it is like someone is at the front door!

Steve Ahola

P.S. I have screwed up plenty of mini-switches and pots from overcooking them with my gas grill, er, soldering iron but other than one polystyrene cap in which I managed to unmelt one of the legs I don't believe that I have mangled up any of my caps...

[Mike Sulzer]

it is the resistor (pot) not the capacitor!

I question your suggestion that a pot set at 10 isolates the capacitor. I have used push-pull pots to remove the tone cap from the circuit and it brightens up the sound considerably. And they do make "no load" pots for tone controls that will do the same when you turn them all of the way up.

As for the suggestion that you would not hear the difference between a 0.022uF cap and a 0.047uF cap with the tone control set to 10, I have one guitar that allows me to switch between those two values and yes, I can hear a subtle difference between the two when the tone control is set to 10. Of course the difference is much more noticeable when you turn the control down.

However, the jury may still be out on the issue of whether you can hear the difference between two different caps of the same value with the tone control dimed... I'm still waiting for the details at 11:00PM...

In any case, there would be no market for no load tone pots if a regular pot completely isolated the tone cap when set to 10.

(Is there an emoticon here for beating a dead horse? Or maybe I should add the disclaimer that no living animals were harmed in the making of this post... )

Steve Ahola

http://www.blueguitar.org/

Steve, I am getting tired of writing the same thing over and over again: It is not the capacitor that is causing the effect when you go to a no load tone pot; it is the resistor (pot). Any resistor connected across the pickup with typical values causes a loss of treble. The capacitor acts as a short circuit in this case at the relevant frequencies so that the resistor is in effect connected across the pot. I have written this several times; you have not responded as if you have understood. Do you see what I mean? If not, can you tell me how I can better make this point?

[Possum]

....

Mike did you not look at SK's oscilloscope tests? Its there in black and white, you can plainly see changes in the audio signal by swapping caps with the tone control being inactive. I WILL post those audio clips tonite, I make pickups for a living, I started this thread because I had previously believe caps made little difference and was startled that my cap change had such a dramatic effect, I did not change the pots :-)

[SteveJ]

If you're doing tests between cap types a Blues Junior is not an ideal test amp.

That brings up a good point. The amp is going to make a big difference as well as your style of playing. If you are playing with the controls on 10 and using effects, lots of gain etc. then the caps probably won't make much difference. If you are working your volume and tone controls and playing through a vintage style amp then there are a multitude of tones available. If the amp tends to color the sound of the guitar then you will be just as well of with pretty much any cap. I also use 50's style wiring. It's just a personal preference but I like the way that it helps retain the high end when rolling back the volume. I almost never have my tone control set on 10. Also think about PAF's. When you run the volume control at 10 they start to sound similar to other humbuckers but when you roll back and find the sweet spot it's incredible.

[SteveJ]

The first link is to NOS Sprague caps at $8 apiece while the second link is to ones made by Good-All at about $1.50 apiece (factoring in shipping).

I was just wondering if you have tried the Good-All caps- are they every bit as Good as they say...? [groan]

I guess that there are 10 lots of 20 caps left but I think I'd want to hear from someone who bought them before plunking down the cash. (I did get the last pair of NOS caps from the first link- thanks for the tip!) With the 100v rating of the Good-Alls its not like I could use them in tube amps but just guitars and stomp boxes...

Steve Ahola

Hi Steve,

Your Welcome. Yes I did order the Good-Alls a while back. Calst is a good seller and his descriptions are accurate to the best of my knowledge. I have a couple of sets of 400V Vitamin Q caps that I compared them to. I couldn't tell any difference. I don't know the history of the manufacturers but my guess is that there was a lot of relabeling going on back in those days. Construction looks identical on many of them and a lot of times the label was just a plastic wrap with the print on it. I would guess that construction techniques were pretty similar if made by another manufacturer anyway. The recipes were probably close. I don't think you would here much difference.

So far I have seen good PIO's under several different labels. I don't know which if any were made by Sprague but they all seem to be very good. They are Sangamo, Good-All, Gudeman, Pyramid, Nytronics, Hyrel and others. One thing for sure is I think these are some of the best caps that can be had and at a decent price. It can't hurt anything to use them.

[Possum]

....

OK, here is audio proof for ya Mike:
http://ur.pair.com/shrapnel/caps/
the file "middle new caps" is the change to .022uf the other file is .047uf. As I said before the middle position shows the difference the most but the bridge and neck both sound quite different from the change as well. These were recorded with identical guitar, identical strings, identical pickup height, same microphones, amp left on same settings, no recording changes, everything was identical, and I know from playing through other amps the change in tone is REAL. You can't deny what you're hearing. Tone is is fully open not rolled back any, so supposedly what you're saying is there is no difference in tone due to value change in cap, well sorry, here it is, take a listen.....

[Steve A.]

Steve, I am getting tired of writing the same thing over and over again: It is not the capacitor that is causing the effect when you go to a no load tone pot; it is the resistor (pot). Any resistor connected across the pickup with typical values causes a loss of treble. The capacitor acts as a short circuit in this case at the relevant frequencies so that the resistor is in effect connected across the pot. I have written this several times; you have not responded as if you have understood. Do you see what I mean? If not, can you tell me how I can better make this point?

Mike:

So what exactly are the "relevant frequencies" and who is it that determines that they are relevant? A 0.022uF cap across a pickup (with no resistor) will bleed off many/most of the high frequencies. Change that to a 0.015uF cap (once again with no resistor) and it sounds a bit like a wah pedal kicked to the back position.

In the original telecaster one of the three positions used the rhythm pickup with a 0.1uF cap going from hot to ground, once again with no resistor. Are we to assume that there were no relevant frequencies produced by this guitar when this position was used (since according to your theory they were all bled to ground)?

I base my statements on electronic principles; with a guitar pickup and a tone control we have resistance, capacitance and inductance which will create RC networks and LRC filters. To discard the capacitor as being irrelevant is in direct contradiction to conventional electronic theory. The resistances, capacitances and inductances all work together to create the guitar signal sent to an amp; change one of the parameters and it will change the sound, perhaps a subtle change, perhaps a not so subtle change.

Perhaps you can cite a book or article which supports your rather unique theories on this subject (I first learned electronics by studying the 1974 Radio Electronics Handbook).

Steve Ahola

[Steve A.]

Yes I did order the Good-Alls a while back. Calst is a good seller and his descriptions are accurate to the best of my knowledge. I have a couple of sets of 400V Vitamin Q caps that I compared them to. I couldn't tell any difference...

Sounds good to me so I ordered a 20 lot. For a price like that I can put them in my friends' guitars for free! (I would not be so generous with the more expensive ones- those suckers are for me and me alone!)

Thanks again for the tips! There are like 700 billion capacitors for sale on eBay and it's good to know which ones work well for the people here.

Steve Ahola

P.S. For testing purposes I might build a little switch box to select between a half dozen different capacitors, and could be used with any of my guitars (I would want to disconnect one lead on the tone caps in the guitar being tested.)