On another thread I started entitled "Stratotelecaster Build.....odd ducks...old farts..." I mentioned that I used a cap on my first tone control that came on a pot from a guitar that someone "tried" to customize". I just assumed it was a older type .22 cap. I was wrong. Please also note the strange brown cap on the first tone control:



When i built the guitar but when I played it the tone control did little of anything and just slightly shaped the tone. It was very subtle. Now I need some help from you cap experts out there. So I took it off and got out a magnifying glass. It says: .0023M on the back. Do any of you know what this is. And it was made in Mexico! ummmm again.




I like old caps so I dug out a few other ones. I have a YF503 on the left and a 473 on the right. I do not have a clue where I got these or what they would do to a tone control. There are few other oddball ones kicking around there too. Anyone know how to read these weird numbers? I know about the k rating like .22 k on a standard Strat pot, but these???

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Some of those can be hard to figure out, but the "473" for example means 47 and three zeros, 47,000 pF, or .047 uF (u = micro). The first two numbers are the value and the third number is the multiplier (number of zeros) indicating the value, in these cases always in pF. A two digit number is simply the value in pF. Some of the letters before or after the three digits are for tolerance, temperature rating and other ratings. The YF 503, is 50,000 pF or .05 micro, with the F likely meaning a +/- 1% tolerance, the Y maybe a temperature coefficient. But, not all manufacturers use the same layout for the numbers, so sometimes it can be difficult to be sure without actually checking the value with a capacitor tester. For the .0023M, it may be the value in uF, and if the M is tolerance it would be +/- 20%, or it could just stand for micro, and a K could mean a 10% tolerance.

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Thanks! Now I need to do some googling and find out what some of that means. Sure would like to know how these different cap might affect the tone. The .0023 did very little. Kind of like it slightly shaped the tone but not anything like a .22 which takes off a lot of the treble end of the signal.

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Xhefri's Guitars
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Anything that I can clear up?

I assumed that you knew the terminology.

Capacitor values are in farads (F), and are usually in microfarad (uF), nanofarad (nF), or picofarad (pF), the prefixes meaning ten to the negative 6, ten to the negative 9, and ten to the negative 12 farads respectively. So, .000000022 F would be .022 uF, or 22 nF, or 22,000 pF. Although the "u" isn't really the symbol for "micro", it is commonly used, probably because I can't remember how to type the real symbol "μ" on my keyboard (I had to copy and paste the symbol).

A capacitor, or "cap" (C) will pass frequencies above its cutoff frequency depending on the value of the cap, and can be wired with a resistor (R) as an "RC" network to control certain frequencies, as in the tone control in the guitar. The guitar tone control is wired as a low-pass circuit and will pass the higher frequencies to ground more as the pot is rotated, resulting in lower frequencies passing to the amp while the higher frequencies are "cutoff" or "passed" to ground. The lower the value of capacitor and/or resistor, the higher the cutoff frequency will be. So using a lower value capacitor for the tone circuit in a guitar would result in less of the high frequencies being passed to ground. In other words on a guitar tone control circuit, a .022 uF cap would give a higher cutoff frequency, more treble having a brighter sound, than a .047 uF cap.

Here is a neat simple calculator to figure the cutoff frequency of an RC network, also showing two circuits, one low pass and one high-pass.

http://www.muzique.com/schem/filter.htm

_________________
---> "The amp should be SWITCHED OFF AND UNPLUGGED before you do this!" <---

Por favor, disculpe mi español, no se llega a la práctica con mucha frecuencia.

find out what values you want and then search for a vintage paper/oil cap.

Isn't that referred to in the term "treble bleed"?

Cheers

David

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Hi Amerigo,

A "treble bleed" is usually a capacitor with or without a resistor, on a volume pot to prevent losing treble as the volume is turned down by allowing the treble (higher frequencies) to "pass" or "bleed" around the vol pot so that the highs are retained in the signal instead of being passed to ground as they would be in a tone control circuit.

_________________
---> "The amp should be SWITCHED OFF AND UNPLUGGED before you do this!" <---

Por favor, disculpe mi español, no se llega a la práctica con mucha frecuencia.

I know it's just that the term was missing in @shimmilou's perfect post. And I wanted to have it mentioned in this thread so that Google will be able to find it in the future.

Cheers

David

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"Humans think they are smarter than dolphins because we build cars and buildings and start wars etc...and all that dolphins do is swim in the water, eat fish and play around. Dolphins believe that they are smarter for exactly the same reasons."