Build Tip: Film Capacitor Polarity Test

Here's a quick and dirty way to test the polarity of film capacitors using only a fuzz pedal and an amplifier. No fancy test equipment needed. This is a MUST for building tube amps where you're running high B+ voltages, especially with heater currents nearby; but it can also help eliminate RF and other noises in stompboxes.

[@nassimkoubeissi5814]

thank you for the great information about capacitors poles this issue is found when assembling a circuit (complex or just a simple circuit ) manually after finish assembly and running a test sometimes the circuit do not behave as it's simulated on a PC this problem is solved on mass production assembly lines by the machine (it's fed by let's say a ceramic capacitor in the way of a chain that have it's printed face up and the left pin is the negative side so when it install the capacitors on the PCB they are installed in the proper polarity based on the PCB circuit ( you can notice this by disssambling 2 radios same brand and model and you notice all the components printed side have exactly the same directionin both radios . I hope to be my information helpful and to keep up the good work .

[@Guttalaser]

THIS is the f****ing way!!!! Damn... tons of YT videos of nerdy guys with $$$$ oscilloscopes ... just for know how i must solder ONCE my 22 uF Sprague Orange Drop to a guitar tone control... and at the end... THIS IS THE WAY!!!! Tnx Man!!!

[@theAristocrap]

This is great! No expensive equipment for us poor amateurs trying to build their first DIY kit! Now I know how to terst for polarity of a capacitor!

[@J.C...]

That's not polarity. Those caps have no polarity. You're only determining where the foil shield is. That IS NOT the same thing.

[@vintagetubeamplifiers]

Best vid on this subject that I've found. Thank you!

[@Alex_Martz]

Awesome!, simple and effective test!, no need to buy an expensive oscilloscope

[@stratdude83]

Simple and effective, best method I've seen this far!

[@gabevee3]

Why not just hook up the scope probe to a 1/4 inch plug? Keeps the test just as simple without the annoying HMMMMMMM.

[@marianmarians6762]

Thanks, how simple trick.

[@choimdachoim9491]

Unbelievably simple !

[@HellcatsUnited]

You are awesome!!! The easiest way to determine polarity!!!

[@martinlicht1969]

Thanks for the great tip!.. or you could wear headphones to not wake up the wife and no need for scope.

[@acidfuzzpedals9986]

Exactly. I added a headphone jack to a lower powered tube amp, exclusively for this reason. In my experience it's much quicker & easier to use this fuzz pedal in to tube amp method than a test jig and scope. Having a tube amp with a headphone jack allowed me to test caps without the fear of being screamed at.

[@RadityoPramAdi]

thank you so much !!

[@Techead78]

Pretty koo😉

[@kilcar]

No Oscilloscope necessary. Love it

[@bigbasil1908]

Cheers.

[@Mario_DiSanto]

Thanks a lot brother

[@jakeallama22]

Very helpful! Question: when building a kinman treble bleed circuit, which end of the cap should the resistor connect to?

[@frederickelectrick6137]

thank you sir. I'm replacing the capacitors in my 1965' champ amp, and this is important for noise reduction in a tube amp circuit, the electrolytics are marked although the orange drops are not. so again thanks for this simple tip. 30+ years working on amps and I learn something new and cool everyday. this is much simpler and faster than connecting to an oscilloscope.

[@acidfuzzpedals9986]

Thanks Frederick. I'm glad you found this tip helpful with your Champ service. I had the same WTF? reaction when I first came across this after pulling some older film caps with the band/mark while servicing a Hitachi amp. For me, life is all about the "ah ha" moments and learning new things.

[@dibyamartandasamanta583]

Can you tell me from where you manufacture your Ge Transistor

[@J.C...]

Determining what side the foil shield is on IS NOT POLARIZATION

[@commieslayer8218]

testing my caps on junior type guitar amplifier but a few of these caps just silenced the sound from disconnected jack at full volume throttle so I can't tell the polarity.

[@EmopunkDr]

Does this polarity matter when soldering a cap on a tone potentiometer in a guitar? Thanks!

[@jasq99]

So cool. For 50’s les paul wiring would it the go foil side to tone pot? Or foil to live lug on the volume pot???

[@sharonlee4773]

Thanks for that,very useful tip! Cheers

[@frankscassi4960]

I'll never install a capacitor without checking it, thank you!

[@swangonzalez4797]

Is this orientation important and applicable to the tone capacitors in a les paul? Thank You

[@mrmaxgain]

Thank you! That does help. I've used a scope to look for the polarity. I never thought of using an amp to boost the signal.

[@terrywho22]

Brilliant!! Many thanks. Now I don't have to head over to my oscilloscope each time I want to check a capacitor.

[@DemonKingOFFICIAL]

Thanks for this vid. I don’t know why I didn’t think to do it like this as opposed to using a scope or doing something complex to find the outer foil.

[@leohobbleohobb3781]

Just what i needed.Have wanted to test all the noploar/bipolar capasitors on a dual riaa stage i am building and do to my left eye had some problems around a little week i had problems with seeing the osilloscope clearly.I play guitar and build hifi high end power amlifier and active dsp controlled speaaker system with planar magnetic technology with push pull neodym magnet bars in front and back of the thin caldex film the voice "coil".A driver like dthis is very senitive one mid they are 6 inch wide and 10 inch high each 96db 1 watt 1 meter. and it is a perfect load for a power amplifier do to the fackt it does not change impedance with frekvens and does not have coil milly henry.So everything in the source and signal chain has to bee quiet quiet.4 of those midrange from 270hz to 1900 with total sensititvity on the 40 inch 6 inch wide planar magnetics drivers in linesource with the 2 upper adjustable angle downwards so they all cross aty listening position.No roof reflectio or florr.The same goes for AMT tweeter section witch is 20inch high and 5 inch wide.tried normal power amplifiers like rotel upper end and nad and higher prized gear.but all off them was negative feedback amps local or global and they made hiss so loud that i could hear it in my listening chair 3.5 meters away easy.with the one i had way back 2000 the end millenium xp i knew it was good.so i build a 4 channel one with 2 double toroidal transformators and 4 full bridge rectifiers and 240 000uf capasitor bank.Have to put my ear against the amt tweeter with around 98db sensistivity to detect the amplfier is on.build as 4 mono inside one cabinett 2 mono modules have one trafo double winded ac42V-042Volt and ac 42volt-042Volt on each trafo.they are 600va each.use autenator on inputs to get unity gain and let the filter run at 0 db on al outputs.when rommcorection or speakersystem frakvens responce is messured all the autenators are at full in.only uses the software to program the ground sound dnc24rpc digital dsp filter stereo 2 way mono with 2 innputs 4 way.i use them in mono config and have 2.One for each side.and man does it work.the customer i know will be a happy guy as the system is similar to the one i am building for him but also things he want that i have to try implement.the best posible soud is the goal.every amp in that system will be small class a near the planar driver for tweeter and midrange with same type filter described earlier.woffer section will have a pwm digital power amp.No switchmode supply alowed in my things

[@dibyamartandasamanta583]

I heard a company from Europe acquired mullard and still making Tropical Fish capacitor. I don't know who they are ...... Any one here know them?

[@ΑργυρηςΚαραπετσας]

Very nice information man! Simple and useful!

[@lesjones7617]

Thanks! will check the Oring drops in my last 2 builds and will get my 3rd correct fro the stars!

[@BadChizzle]

Very useful. Thanks!

[@rayheilman9707]

awesome tip, thank you kindly for sharing!

[@marvinbrando]

Good tip. I was looking for this info and quickly found this video. Thanks.

[@J.C...]

Dude you're misinformed. Or you've mixed up properties from different caps into one big amalgamation and now don't know the difference between them.

[@acidfuzzpedals9986]

“Dude”….., Respectfully, I’ve been building/working with electronics for over 30 years. “Polarized” has many definitions, aside from describing the opposing regions/electrical properties of transistors, batteries, electrolytic capacitors, etc… Here I’m using the term to express the opposite ends of a film capacitor, the outer foil end (typically to ground/lower impedance), and inner foil end(s). Obviously, the term is also used in politics and physics.

[@andrewhutchinson3968]

Awesome I've been looking for info like this for a while . Thankyou

[@robertjackson7160]

This really does help . Thank You .

[@leohobbleohobb3781]

great tip.much easyer than use a osilloscope

[@kilcar]

No oscilloscope needed!

[@AdamSJarrett]

This is great info! So if I have this right, the foil end goes to ground on a tone pot for example, correct? How does this work when doing a treble bleed circuit, specifically the Kinman wiring in series? is there one side that goes to the middle/outer lugs specifically?

[@Technostiel]

So the outer foil wire goes to the top of the potentiometer and the other wire to the lug?

[@aaroneisenstein4663]

Correct, foil end goes to ground, anywhere in the circuit, not just the tone pot.

[@elcochipit]

nice and efective tip! thanks for share

[@SarcastSempervirens]

THANK YOU!

[@psnpacific]

Great tip!!! 👍

[@mikecamps7226]

excellent novel approach to this matter...….nice short cut

[@tomasmaly2588]

nineball26 maybe just u are wrong, if you are little more interesting about this problematic you should know well which is which this manual is really good i go to build fuzz efect only for this :D. And for the question, when is the capacitor connect on the jack the part which is on the top of the jack (position for signal) is positive if the noise is smaller its mean that this end of capacitors must be always on the bigger potencial ( higher voltage or if you vant them typicaly more at end in the signal way) really waste? Sometime is enough if u just know what are you looking for..

[@kerrybayton8356]

That has helped a lot.. A quick & easy way to check direction. Thanks..

[@omarveytia3574]

it would be awesome to get more practical pedal building tips like this!!

[@acidfuzzpedals9986]

Is there anything in particular you would like building tips on?

[@stewps13]

Hmmm, off the top of my head... Well, I pick up a bunch of old distortions and fuzzes and deal with a lot of noise from energy sources, like whenever theres a battery or power supply plugged in. Maybe that could lead up to a video on troubleshooting pedals or somethin

[@dibyamartandasamanta583]

Sir from where you get your germanium transistor. I need them to build some class A headphone amplifier

[@rodolfoamaralguitar]

Does the polarity interfere in the tone on a guitar wiring?

[@acidfuzzpedals9986]

Generally, no. Polarity of tone capacitors in passive guitar wiring does not matter. Incidentally, only the value of the capacitor matters in terms of sound. Dielectric type, or what the capacitor looks like, does not matter. If you're restoring a high value vintage guitar and want to maintain originality, that's one thing. Paying a lot of money for Bumble Bee or other vintage capacitors thinking it will make a difference in sound is ~snake oil.

[@rodolfoamaralguitar]

@@acidfuzzpedals9986 thank you

[@jeeplvr2000]

How do you set up your scope to do this test?

[@zer0b0t]

I thought those didn't have polarity, btw how about replacing those with electrolytics? Will it be less noisy?

[@watcher818]

I doubt there are electrolytics in the small values caps here. those look like they are under .1uf The polarity he speaks of is really the outside foil lead. Technically the old marked caps were not polarized either. Marked line denoted outside foil. The outside wrap will pick up the hum in your finger, that way you know which lead is the outside one.

[@justgrant2022]

Great video, how's the acid fuzz Wah Wah pedal coming?

[@acidfuzzpedals9986]

We prototyped it back in ~2012-13 and it's been ready for production since then. We're not releasing it until at least fall of 2017.

[@JosefRosam]

@@acidfuzzpedals9986 hey, was this cancelled? i wish i could purchase an acid fuzz wah!

[@michaelhiggins6223]

I am not an expert. However, I bought a HoneyTone mini-amp to try this. It did not work - period. I bought a fuzz pedal to increase sensitivity, gain, and supply a different signal. It did not work - period. Fool me once shame on you. Fool me twice shame on me.

[@acidfuzzpedals9986]

Sounds like you're not testing foil film caps or: kzbin.info/www/bejne/m3zKgYxnlsmWZqM

[@michaelhiggins6223]

Could be. All the caps I tried look exactly like the first brown dip you tested. I tried 0.0022uF to 0.1uF 630V caps I was prepping for a Hallicrafters S-85 restoration. I can test capacitance/ESR with my $8 Chinese LCR meter. I can test capacitance and leakage with my rebuilt/calibrated Heathkit IT-28 no problem. I cannot get any hum from the setup you show with the amp and pedal, unless I touch the lead that is on the cable tip. Perhaps if you provided some more details like the type of amp you use - tube? Three prong or two AC cord? Amp and fuzz pedal settings? Just grasping at fooling me thrice...I think if I get an o-scope that has voltage scale sensitive enough to my 98.6Hz hum, I might be able to see the diff.Thanks for trying though.

[@lingcod91]

Wondering if you ever got that problem worked out . . . since I've had the same results. I'd ask Fuzzy but I expect to go the same answer you did . . . Nothing. Any help would be appreciated.

[@gabevee3]

Where were you when you tried it? Inside a home one picks up the EM from the electrical system. Not as much in a garage or outdoors. No one is trying to fool you. This is correct information. Plus, make sure you are holding the capacitor the way he is.

[@markdelvecchio9316]

Where can I buy one

[@acidfuzzpedals9986]

Mark, I'm not sure what you're asking to buy. If you just want a fuzz to bump the gain of your amp to make it easier to discern polarity, ~any dirt pedal should work. If you're interested in one of our pedals you can check our website acidfuzz.com or email us at [e-mail]. Thanks!