Calling all super sleuths!

[digi2t]

Tracing out an old Royal Cosmo Wah, but these three components have me stumped. Apparently, it's a ringmod / wah pedal.

They have the Matsushita/Panasonic logo, but the nomenclature doesn't seem to ring the Google bell. I'm thinking maaaaaybe inductors, but I'm not sure.

Best pictures I have at the moment...

[italianguy63]

how big are they?

[Nitefly182]

Where are they in the circuit? They look small for inductors unless they're very small values. Only two legs?

[Gus]

I have seen electro caps that were in plastic packages that somewhat look like the picture show however they were not Pansonics
Do they have a polarity mark on them?

EDIT I did not find a picture of the old hard plastic radial lead Mallory electrolytic caps I was thinking of but I did find this it looks like a hard plastic case
https://www.mouser.com/datasheet/2/427/036rsp-1762297.pdf

[vigilante397]

I'm leaning toward capacitors, but I would love more infor like size, number of pins, location in circuit. Do you have a capacitance meter? That would be a pretty easy way to rule some things out.

[anotherjim]

I'd say caps too - they even have the cranked out legs option of those Vishay ones linked. Also first time I seen components classed as semi-professional - do they have a day job?

[Mark Hammer]

I'd say caps too - they even have the cranked out legs option of those Vishay ones linked. Also first time I seen components classed as semi-professional - do they have a day job?

They used to, but they've been laid off recently, because of you know what.

[Rob Strand]

The hard plastic case makes me think inductors.   Nearly all the crazy looking parts with hard plastic casings I found when I was a kid turned out to be inductors (big/small/round/square).   However, I have seen non-polar caps from with plastic casings, large round 20uF to 100uF ones from the 70's  and some square 2n to 20n Rifa polystyrenes from the 80's.

Inductors will obviously have a DC resistance (typ. below 100R).  Caps will be open circuit.   Measuring in-circuit can put you off the scent but the low inductor resistance helps.

When you trace the ckt it should be obvious from the circuit arrangement.   Those parts could be inductors in series, or, caps/inductors that are switched.

EDIT 1: another trick is to look for PCB pics on-line, funky parts on some units look normal on others.

http://electricpartslibrary.hatenadiary.jp/category/Japanese%20Vintage%20BIZARRE%20Effect%20collections%20by%20TIX

I'm seeing three  green ceramic devices in a row near a transistor, but I'm not sure it's in the right place. 

EDIT 2: I'm leaning towards caps based on the size.

[digi2t]

You guys were right for the most part. Caps they are. Bart was nice enough to take a pic of the backside of them. 0.47u/25v.



Many thanks to one and all!

[Rob Strand]

Bart was nice enough to take a pic of the backside of them. 0.47u/25v.

Perhaps caps for a phase-shift oscillator.

[digi2t]

Bart was nice enough to take a pic of the backside of them. 0.47u/25v.

Perhaps caps for a phase-shift oscillator.

I'll post a schemo as soon as I have it all traced out. He's sent me more pics, I'm still piecing it together.

[duck_arse]

they must be chockas with wicked mojo.

doesn't seem quite right to me, usually the low low value electros (0u47) are big voltage rating, whereas a 47uF 25V would be about right. maybe film types?

[digi2t]

they must be chockas with wicked mojo.

doesn't seem quite right to me, usually the low low value electros (0u47) are big voltage rating, whereas a 47uF 25V would be about right. maybe film types?

Bart wrote that it's "0,47/25". If I look at the pictures he's sent, I can clearly see the "0" in one angle, and the "47" in an other. So, they're 0,47uF.

Got more pics last night, and just some outstanding questions remain on some components and wiring. Developing the schemo today.

[Rob Strand]

doesn't seem quite right to me, usually the low low value electros (0u47) are big voltage rating, whereas a 47uF 25V would be about right. maybe film types?

It's hard to know if they are films but they do look a bit small.  The plastic encased caps I saw from the 70's were high value, they were non-polar electrolytics, and had larger packages (like a 100uF 35V electro).  The pics in the link I posted earlier show three green ceramic caps and 0u47 makes a lot of sense there.

[anotherjim]

If they are non-polar, couldn't they be a series pair of electrolytics? That explains the need for a plastic cover since the neg ends are in the middle and can't be common with the outer can of a normal polarized electro.

We're used to caps below 1uF being anything other than electrolytic, but back then, electro caps could be in sub 1uF values. 100nF electro's exist.

[digi2t]

I have pictures of the trace side, and there only seems to be two leads for each component. Besides, as Rob mentioned, there is another unit pictured with the same components in what looks to be a ceramic or poly package.

There's an arrow pointing down to a flat line on one lead side. I think that might be the negative lead.

I've seen sub-1u electros used before in a couple of circuits (Schumann PLL springs to mind), but yeah, not common.

[Rob Strand]

If they are non-polar, couldn't they be a series pair of electrolytics?

There's an arrow pointing down to a flat line on one lead side. I think that might be the negative lead.

I've seen sub-1u electros used before in a couple of circuits (Schumann PLL springs to mind), but yeah, not common.

No doubt a possibility.

Since the thread was put up I remembered I had seen parts like that before.   Probably out of an old radio from the 70's.   I remember because they look like germanium transistors but they aren't.   I probably didn't bother pulling them off the board because a lot of old radios had the legs cut to the PCB thickness and so I never bothered to identify what they were.