# have I been installing capacitors backwards?



## Lincoln (Jun 2, 2008)

This is news to me. I didn't know that there was a right and a wrong way to install non-electrolytic capacitors until I stumbled upon this video:

[video=youtube;BnR_DLd1PDI]https://www.youtube.com/watch?v=BnR_DLd1PDI[/video]

apparently one lead of every capacitor is attached to an outer layer that acts as a shield, and this lead needs to be on the lowest impedance side of the circuit. Makes sense.

I'd really like to hear from the experts on this. Is this something I should be concerned about on a guitar amp? Should I be concerned enough to tear apart everything I've already done and start over? Are there areas in a circuit where it is more important/less important? :confusion:


----------



## blam (Feb 18, 2011)

i tried this with orange drop caps and some random PIOs and i didn't find a difference foreward or backwards....but i may have built the rig incorrectly...


----------



## jb welder (Sep 14, 2010)

Many are not marked in any way. I can guarantee you that no major manufacturers of guitar amps pay any attention to this detail.
Most of your favorite classic tracks were made by amps with capacitors installed "backwards" :sSig_busted:.

I'm sure I'll hear some arguements on this one.


----------



## Lincoln (Jun 2, 2008)

jb welder said:


> Many are not marked in any way. I can guarantee you that no major manufacturers of guitar amps pay any attention to this detail.
> Most of your favorite classic tracks were made by amps with capacitors installed "backwards" :sSig_busted:.
> 
> I'm sure I'll hear some arguments on this one.


Like carbon comps? Just adds to the mojo!

I panic'd at first but I'm starting to realize it's a bunch of bunk. 

and What's with that guy's test equipment? Does he really need or even use all that stuff he has around him?


----------



## greco (Jul 15, 2007)

Lincoln said:


> What's with that guy's test equipment? Does he really need or even use all that stuff he has around him?


Amazing...maybe he has some sort of Electronics Test/Measure GAS??

If the orientation of caps is of any real importance, why is this the first time it has been mentioned... AFAIK (after reading quite a few electronics texts and many, many sites/forums on the internet).

Interesting thread. Thanks Lincoln.

Cheers

Dave


----------



## 5732 (Jul 30, 2009)

All the tone is in the correct combination of forward and backward caps.


----------



## dtsaudio (Apr 15, 2009)

About the only truth in that was that there is an outer and inner foil. The cap doesn't care which direction it's placed. You might find benefit of the shielding of the outer foil at RF frequencies but certainly not at audio frequencies. 
Now electrolytics placed backwards can be mildly spectacular.


----------



## nonreverb (Sep 19, 2006)

Actually majorly spectacular!! 



dtsaudio said:


> About the only truth in that was that there is an outer and inner foil. The cap doesn't care which direction it's placed. You might find benefit of the shielding of the outer foil at RF frequencies but certainly not at audio frequencies.
> Now electrolytics placed backwards can be mildly spectacular.


----------



## Lincoln (Jun 2, 2008)

blam said:


> i tried this with orange drop caps and some random PIOs and i didn't find a difference foreward or backwards....but i may have built the rig incorrectly...


I'm thinking that's because on the caps you tested there was no difference. The guy probably spent years finding just the right "random" caps for his little demo.


----------



## knight_yyz (Mar 14, 2015)

Some of the larger power supply caps do have arrows for direction, but I was always under the impression that no arrows meant it didn;t matter




















it does matter which way these go
.


----------



## parkhead (Aug 14, 2009)

"apparently one lead of every capacitor is attached to an outer layer that acts as a shield, and this lead needs to be on the lowest impedance side of the circuit. Makes sense."

this has very little application for guitars amps 
as someone noted None of the vintage amp MFG paid attention to the foil markings during assembly 

the HI FI guys like to replace every capacitor in an amp, 
however in guitar amps unless they are leaking DC the older cap are part of the sound 
there is distinct warmth and swirl imparted by mullard mustards in Marshalls and the old blue molded and yellow astron caps in fenders 

the bumble bee aka sprague 160p is essential to the tone of the burst les pauls 
again you see them installed both ways in old les pauls 

finally in tone control circuits in guitars 
they do actually sound different forwards vs backwards 
with the foil side toward the volume control imparting more sizzle 

p


----------

