Can you help identify these strange capacitors?

atomicmg · Post by **atomicmg** » 29 Jan 2011, 03:22

Hi everyone. New to the forum - hope to learn a lot.

Trying to duplicate a current pedal schematic. Just hung up on a few strange "capacitors". At least that's what I think they are.

Look at this pic, and at the top, below the two normal resistors, you see two pink components, a green one, and then a small mustard-seed looking thing. They all have a "CXX" designation on the board, so I'm assuming they're caps. Yet I don't know how to get the value on them. The mustard seed has some numbers, but nothing close to a cap value designation?

Any help?

Much appreciated!

atomicmg · Post by **atomicmg** » 29 Jan 2011, 03:56

Ok, I've discovered that the small yellow ones are "multilayered ceramic capacitors." Still trying to decode the value from what is printed on it.

Any info on the others?

RnFR · Post by **RnFR** » 29 Jan 2011, 11:40

they look like resistors to me. silk screens aren't always right. if you can't read the cap, just desolder and measure it.

h8mtv · Post by **h8mtv** » 29 Jan 2011, 11:52

The bottom one, marked C4 is def a cap. I have some 220n that look like that. You prob will have to remove and measure it though.

Dirk_Hendrik · Post by **Dirk_Hendrik** » 29 Jan 2011, 12:07

Correct me if wrong. Is that a Marshall board?

Hides-His-Eyes · Post by **Hides-His-Eyes** » 29 Jan 2011, 13:53

Looks like an axial ceramic to me.

DrNomis · Post by **DrNomis** » 29 Jan 2011, 14:45

I have a PCB that originally came out of an old Trace Elliot Tramp Head,it has some of those on it,they are most deffinitely capacitors,to read the values marked on them,you read the numbers as you would for surface mount chip resistors,but in this case,the values are in Nano-Farads,here are some examples:

102= 1000 (one,zero,and two more zeros).

This is equal to 1000 pF,or 1 nF....

472=4700 (four,seven,and two zeros).

This is equal to 4700 pF,or 4.7nF.....

474=470000 (four,seven,and four zeros).

This is equal to 470,000pF,or 470nF....

RnFR · Post by **RnFR** » 29 Jan 2011, 16:12

yes fellas, that's an axial ceramic. he figured that one out on his own, and it doesnt have the value clearly marked. i can pretty much guarantee that the 9419 shown on the part has nothing to do with cap's value. it may be on the other side. regardless, he'll have to desolder.

now, what the op wants to know is, what are the components marked C1, C2, and C3- which are obviously resistors, albeit a bit fruity looking.

atomicmg · Post by **atomicmg** » 29 Jan 2011, 16:18

Wow thanks everyone!

I did find the value of the little yellow guys - it is on the opposite side, which was very hard to see. I got values like "K5U 224M" = .22uF

But I still am struggling with the pink and green guys. I don't really want to desolder as I don't want to risk any damage - and I've just sold this pedal, and will be shipping it next week. The colored bands ought to tell me something, right? I have a nice multimeter, but it doesn't measure capacitance. Maybe I should find one that does?

DrNomis · Post by **DrNomis** » 29 Jan 2011, 16:46

atomicmg wrote:Wow thanks everyone!

I did find the value of the little yellow guys - it is on the opposite side, which was very hard to see. I got values like "K5U 224M" = .22uF

But I still am struggling with the pink and green guys. I don't really want to desolder as I don't want to risk any damage - and I've just sold this pedal, and will be shipping it next week. The colored bands ought to tell me something, right? I have a nice multimeter, but it doesn't measure capacitance. Maybe I should find one that does?

The colour bands are read same way as for resistors,I'm guessing that the marked value is either in pF or nF.....

I came across some of those style caps when I was doing some restoration work on an old Peavey TKO 80 Bass amp....

danielzink · Post by **danielzink** » 29 Jan 2011, 16:50

On this page:

http://www.robotroom.com/Big-Trak-2.html

the third paragraph marked "Capacitors" shows one of his pink "resistor looking" capacitors.

This is one of few references I can find to this type of cap.

Dan

atomicmg · Post by **atomicmg** » 29 Jan 2011, 17:09

Thanks everyone. That helps. I'll look into the color bands and try to figure them out. There are only two different varieties on the board, so it shouldn't be to onerous.

Thanks!

RnFR · Post by **RnFR** » 29 Jan 2011, 22:34

well, put me in a dress and call me Sally. you learn something new everyday. I'd bet a search for capacitor color codes will get you a chart for the values. probably the same as tropical fish.

but, don't take my word for it!

Greg · Post by **Greg** » 30 Jan 2011, 12:32

And here you see pink resistors..

http://www.hificollective.co.uk/compone ... stors.html

Hides-His-Eyes · Post by **Hides-His-Eyes** » 30 Jan 2011, 13:19

a truely supreme carbon film resistor, specifically developed for Audio

Why not just use metal film then?

blackbunny · Post by **blackbunny** » 30 Jan 2011, 13:28

Both these types were fairly common in 80's Peavey solid state amps and late 80's - mid 90's Marshall Valvestate amps.

The mustard coloured bead C3 is indeed a multilayer ceramic cap similar to a monolithic.

IIRC, C1 and C2 are 10nF and C3 would be 100pF.

The manufacturer used the pink base colour for values from 1nF and up, and the pale green for values below 1nF.

I don't remember what type of caps these are though...it was a long time ago, I could be dreaming.

blackbunny · Post by **blackbunny** » 30 Jan 2011, 13:38

Erm, the mustard-coloured bead is C4, not C3.

Time to go to bed, methinks.

atomicmg · Post by **atomicmg** » 30 Jan 2011, 19:44

Well I finally just desoldered them and measured them

Blackbunny, you were very close.

C1 and C2 are actually 1nF, and C3 was 150pF.

Thanks everyone for your help!

blackbunny · Post by **blackbunny** » 01 Feb 2011, 08:06

I found some info on these:

http://docs-asia.electrocomponents.com/ ... c1e2fe.pdf

There are still a few values listed on the RS Online UK website.
Haven't seen them anywhere else.

Tonetweaker · Post by **Tonetweaker** » 02 Feb 2011, 04:09

blackbunny wrote:The manufacturer used the pink base colour for values from 1nF and up, and the pale green for values below 1nF.

I don't remember what type of caps these are though...it was a long time ago, I could be dreaming.

I believe you were correct on the values, blackbunny...

They're called "tape and reel" ceramic caps... Some electronics manufacturers used them because they could be fed through the same machinery used to place reels of axial resistors. I've never seen the process in action, by my understanding is that "tape and reel" components are actually placed on a roll of tape and then rolled up onto a reel. The end of the reel is then fed into the machine that populates the board so that it can pick the components off one at a time.

Here's a little Steve-proof toy I use to correctly identify color codes, which includes caps and inductors...

http://www.silentmods.com/modding/color_code.html

Cheers...
Steve