Question about values of ceramic caps

[pete1729]

Can anyone ID these caps? They do not appear on the schematic for my Pilot SA-232.

 

[pete1729]

Here are some gore shots of the filter caps.

 

[Mumbles]

First one is 10 pF, or 0.00001 uF. Next ones are 2 pF and 15 pF.

 

[pete1729]

First one is 10 pF, or 0.00001 uF. Next ones are 2 pF and 15 pF.

Thank you so very much.

 

[gadget73]

values are in picofarads, but there is no decimal or multiplier on these old ones.

100pf
20pf
150pf

they are also unlikely to be bad, so unless a leg breaks off I'd probably leave them alone.

 

[Mumbles]

values are in picofarads, but there is no decimal or multiplier on these old ones.

100pf
20pf
150pf

they are also unlikely to be bad, so unless a leg breaks off I'd probably leave them alone.

Not according to this tool:

Capacitor Reader

Capacitor Code Reader. You can enter the 3-digit value codes found on some capacitors to convert it to it's respective farads and vice versa. You are also able to see all these values in microdfarads (uf), picofarads (pf), or/and nanofarads (nf).

leeselectronic.com

 

[heyraz]

They do not appear on the schematic for my Pilot SA-232.

I know of 2 versions of the SA-232. One has 2 speaker taps (8 Ohms & 16 ohms), the other has 3 speaker taps (4-8-16).

The 2 schematics have subtle differences. Make sure you're looking at the appropriate schematic.

 

[mrwood200]

Not according to this tool

values are in picofarads, but there is no decimal or multiplier on these old ones.

100pf
20pf
150pf

they are also unlikely to be bad, so unless a leg breaks off I'd probably leave them alone.

Maybe this tool is for newer capacitors..?
I type in the capacitor info to Google & get https://www.tedss.com/2020117590
Similar cap & 100pf
YMMV but I find gadget73 is very rarely wrong. We might have a difference of opinion, but not with facts.

.....one example! These caps unlikely to bad, AOK to leave them alone...but I have heard that they sound bad. If I am doing a recap for me & these are in the signal path, I would probably replace them.

 

[Mumbles]

Maybe this tool is for newer capacitors..?

I've used lees tool for several years now when buying ceramics without any problems. I'm getting the same results with this tool to.

I thought one of the big three, Mouser, Digikey, or Newark had a tool to but I can't find it.

Capacitor Value Calculator

This Ceramic Capacitor Value Calculator calculates the capacitance value of a ceramic capacitor if the capacitor code is provided in the input field, or vice versa.

circuitdigest.com

 

[gadget73]

That style of cap marking is a newer thing. Surface mount and the like use it. Stuff from the 50s didn't use it. Not going to say its impossible I'm wrong on this, but experience with this old stuff tells me the number printed on the cap is the value.

 

[pete1729]

I know of 2 versions of the SA-232. One has 2 speaker taps (8 Ohms & 16 ohms), the other has 3 speaker taps (4-8-16).

The 2 schematics have subtle differences. Make sure you're looking at the appropriate schematic.

Ok then, my amp has three taps per channel; 4, 8, and 16 ohms.

Both of the schematics I have, one from SAMS, the other from Pilot Radio Corporation, have just two taps; 8, and 16 ohm.

 

[heyraz]

Try this...

 

[pete1729]

Try this...
View attachment 3349209

Well, there it is. Thanks!

 

[pete1729]

Try this...
View attachment 3349209

The noted values confirm what Gadget said.

 

[Mumbles]

That style of cap marking is a newer thing.

Thanks for pointing this out as I wasn't aware. Is there a specific year the change was made or would it have been something gradual, over several years?

 

[gadget73]

that I don't know. I've seen it on 80s gear for sure. May have been around in the 70s too. I wouldn't be too surprised it it appeared outside the US quite a lot earlier.