Are Your Capacitors Installed Backwards?

Discussion in 'The Workbench' started by 67Mopar, Jun 27, 2019.

  1. gldtp99

    gldtp99 Active Member

    Joined:
    Nov 29, 2010
    Messages:
    331
    Likes Received:
    177
    Location:
    Arlington, Texas
    My capacitors are sometimes backwards.

    Sometimes upside down.

    I'm trying to figure out how to get them to be inside out.

    It might be a while on that one. :):):):)

    Go ahead and test for outside foil if you want to, I'm not interested in it.

    Every 4 and 5 gain stage Hi Gain build I've done has worked/sounded just fine without sweating Outside Foil Orientation.

    I put this in the "Run, Forrest" category. :duel:
     
  2. fifteenohms

    fifteenohms Well-Known Member

    Joined:
    Sep 30, 2010
    Messages:
    1,071
    Likes Received:
    537
    Location:
    Los Angeles, CA
    The boss at work has been saying this about me for years.
     
    gldtp99 and jensvonbustenskjol like this.
  3. NewReligion

    NewReligion Well-Known Member VIP Member

    Joined:
    Nov 17, 2009
    Messages:
    10,919
    Likes Received:
    7,761
    Location:
    Paradise

    It is no extra bother for me. I pull a lot of caps on my mods. I'd rather take 5 minutes and test my replacement caps. It is the .0022uf < that are of the greatest concern.

    Attention to detail has served me well.

    David...♫
     
  4. ampmadscientist

    ampmadscientist Well-Known Member

    Joined:
    Jun 26, 2014
    Messages:
    13,350
    Likes Received:
    7,225
    Location:
    Start the reactor... Free Mars!
    In other words your amps are noisy and you pretend that they are not...I understand.
    A lot of people pretend that the noise isn't there.
    But to critical musicians, it's there. They hear it, they hate it.
    I can't stand it and I want to get rid of it. So I'm making the effort.
     
    NewReligion likes this.
  5. ampmadscientist

    ampmadscientist Well-Known Member

    Joined:
    Jun 26, 2014
    Messages:
    13,350
    Likes Received:
    7,225
    Location:
    Start the reactor... Free Mars!
    "...already has zero noise floor for all intents and purposes is silly..."

    There is no amp w/ a "zero" noise floor. Stop yanking the chain I know better.
    It's silly to you.
    To critical listeners it's not so silly.

    Not my first rodeo.
     
    Last edited: Jul 20, 2019
    NewReligion likes this.
  6. FourT6and2

    FourT6and2 Active Member

    Joined:
    Dec 3, 2010
    Messages:
    443
    Likes Received:
    226
    You're cherry picking what you want to respond to in my posts. That's what's really silly. I clearly said right after that sentence that yes I know no amp will have "zero" noise floor. And that's exactly what "for all intents and purposes" means. I don't play amps with test equipment. I play amps with a guitar and my ears. If there is no audible hum/buzz/noise... then there's nothing to fix. Critical listeners? Go hang out at the gear page and talk about how guitar straps alter the tone of an amp with the rest of the "critical listeners." There isn't a single popular guitar amp company out there that takes the time to test the orientation of signal caps in their amps. Marshall, Mesa, Fender, Bogner, Diezel, Soldano, KSR, you name it. Maybe some one-man-shop uber boutique company nobody's heard of. But if a Diezel Herbert or a KSR Gemini or Bogner Uberschall can be noise-free with all those gain stages, then a run of the mill JCM800 or JTM45 or Super Lead can as well.

    Does the outside foil make a difference? Clearly. I'm not debating that. Just that it really isn't worth the trouble to many. Especially if the amp is built well and with proper layout. Not paying attention to the outside foil can lead to the caps picking up noise. But only if there is noise to pick up. If the amp is built properly to begin with, there shouldn't be any noise/interference for the caps to induce into the signal. It's a band-aide fix. If caps are picking up noise, worry about the source of the noise and address it. I trust successful amp designers I've met and conversed with and who have been running their global companies for decades, over some rando on a forum who always rants about aluminum chassis.

    Go to NAMM and ask each and every amp builder there if they test their caps for outside foil. Then you can brag about how many rodeos you've been to.
     
    Last edited: Jul 23, 2019
    J Saw and gldtp99 like this.
  7. gldtp99

    gldtp99 Active Member

    Joined:
    Nov 29, 2010
    Messages:
    331
    Likes Received:
    177
    Location:
    Arlington, Texas
    :blah::blah::blah:


    Next you're probably going to go on and on about $800 power cables:

    https://www.thecableco.com/cables/power-cables/perfectwave-ac-12-power-cord.html
     
    Last edited: Jul 23, 2019
    FourT6and2 likes this.
  8. wakjob

    wakjob Well-Known Member

    Joined:
    Dec 29, 2011
    Messages:
    4,963
    Likes Received:
    3,132
    Location:
    C-137
    I replaced every resistor in my 2204 with 2-3 watt metal film, and every signal cap to Wima MKP/MKS Polypropylene or PET.

    With the Gain and Volume up full, guitar on 10 with the strings muted, going into a 4x12 t75's...you could barely hear a thing coming through the speakers.

    Almost killed my left ear testing that.

    Just thought I'd add to the topic.
    I like caps...chicken.
     
    FourT6and2, 67Mopar and NewReligion like this.
  9. mickeydg5

    mickeydg5 Well-Known Member VIP Member

    Joined:
    Sep 30, 2011
    Messages:
    22,029
    Likes Received:
    9,544
    Location:
    US of A
    [​IMG]
     
    wakjob likes this.
  10. ampmadscientist

    ampmadscientist Well-Known Member

    Joined:
    Jun 26, 2014
    Messages:
    13,350
    Likes Received:
    7,225
    Location:
    Start the reactor... Free Mars!
    "you could barely hear a thing coming through the speakers."

    Your amp is biased cold?
    You turn the volume down to Buddy Holly level?
    You have wimpy preamp tubes?
     
  11. mickeydg5

    mickeydg5 Well-Known Member VIP Member

    Joined:
    Sep 30, 2011
    Messages:
    22,029
    Likes Received:
    9,544
    Location:
    US of A
    It is what it is.
    Do what you like.
    Do not worry about what others think or say.
    Be happy.
     
    Last edited: Jul 24, 2019
    wakjob and NewReligion like this.
  12. wakjob

    wakjob Well-Known Member

    Joined:
    Dec 29, 2011
    Messages:
    4,963
    Likes Received:
    3,132
    Location:
    C-137
    I guess I should have said the floor noise was near zero.
    Almost no hiss at full gain & volume, couldn't tell if the amp was "on" or not.

    NOS 12ax7's and =W= el34's bias 60%.

    As a side note, the amps distortion/clipping texture was horrible with this setup. Very sharp brittle, and it was so sensitive I could hear my cable rubbing across the floor through the speakers.

    I reverted every cap & resistor systematically one by one back the polyester flim/foil & Phier's, and played the amp each time I changed each thing.

    The result was with each step, the amp started sounding less revealing and more "warm". The clipping smoothed back out. An odd increase in midrange frequencies that I'm sure were there before but were lost with the 'Hi-Fi' caps & resistors.

    uh..I'll stop...I get it...people whom haven't experimented with this stuff enough won't believe us because...mAtH.
     
  13. ampmadscientist

    ampmadscientist Well-Known Member

    Joined:
    Jun 26, 2014
    Messages:
    13,350
    Likes Received:
    7,225
    Location:
    Start the reactor... Free Mars!

    The is no amp with a "zero" noise floor. It doesn't exist.

    "NOS 12ax7's and =W= el34's bias 60%."

    Cold Bias. The bias shuts the output tubes off when there is no sound.
    Then, the noise will be reduced greatly.
    The output tubes will work like a noise gate when the bias is cold.

    Test conditions:
    no guitar plugged in, no effects plugged in.
    Bias 70%
    Turn Channel volume to 10.
    Turn Master volume to 10.
    Now you can judge how much noise the amp really has; and there will always be some noise.

    High gain amp: there will be more noise.
    Low gain amp: there will be less noise.
    But there will always be "some" noise.
     
    Last edited: Jul 25, 2019
    wakjob and NewReligion like this.
  14. NewReligion

    NewReligion Well-Known Member VIP Member

    Joined:
    Nov 17, 2009
    Messages:
    10,919
    Likes Received:
    7,761
    Location:
    Paradise
    Agreed.

    But some guys confuse Signal vs Noise vs Power Hiss. But there is always some noise.

    PT's can hum/buzz etc... One thing to remember from my perspective is that some sounds are either Subsonic or Hypersonic out of the range of the human ear. I have read if you can't hear it then it does not matter. I respectfully disagree.

    If I can see it on a scope it is affecting the signal, though one may not realize, just as a poor coplanar layout can add capacitance...It matters to me in addition to .0022uf < caps as they are indicative of passing only higher freq's.

    I take the time to build each amp as if it were mine as they are with my name on them.

    Just my $.02 This is what makes each of us individual builders. I will add that building a medium gain High Clipping Jose is less likely to exhibit exponential hiss/noise/gain than say a 4 stage all tube high gain build. The most problematic are the 4 stage high gain non cathode follower builds regardless of being ENGL, Bogner/Cameron/Roccaforte or my own designs. These builds when done correctly especially with buffered loops and accessories must be given great care IMO.

    Okay, there is $.05 worth lol...Peace out.

    David Hopkins...♫
     
  15. NewReligion

    NewReligion Well-Known Member VIP Member

    Joined:
    Nov 17, 2009
    Messages:
    10,919
    Likes Received:
    7,761
    Location:
    Paradise

    Hey brother John. I hope all is well. The Gen 1 BE 100 #170 is still in the family. I gave it too my oldest Son when he graduated Rose Hulman Masters in Engineering Management. It goes well with his 2011 Custom Blueface Diezel VH4 Peter built for him.

    Thanks bro. Miss not seeing you around. Maybe I will ship you one of my builds round trip to try out sometime.

    Best to you as always.

    David...♫
     
    wakjob likes this.
  16. Ken Underwood

    Ken Underwood Well-Known Member VIP Member

    Joined:
    Oct 16, 2013
    Messages:
    192
    Likes Received:
    617
    Location:
    Annesley, Nottinghamshire UK
    Just come across this thread, and after 56 years then i feel that some one is trying to re-invent the wheel.

    There are mainly two types of capacitors, electrolytic, fixed plate which are un-polarized, ie no polarity.

    Electrolytic capacitors are mainly used for DC decoupling and are polarized so have to be the correct way round ie -/+ terminals.

    If anyone has the basic of electronic theory, and you need too, then a thread like this one would have not been made.

    In a nut shell for you guys who maybe tempted in carrying out minor repairs then dont let a post such as this confuse you.
     
    gldtp99 likes this.
  17. Gunner64

    Gunner64 Well-Known Member Premium Member

    Joined:
    Nov 16, 2013
    Messages:
    4,839
    Likes Received:
    5,393
    Location:
    Midwest, USA
    There you have it. From one of the founding fathers of Marshall Amplification.
     
  18. mickeydg5

    mickeydg5 Well-Known Member VIP Member

    Joined:
    Sep 30, 2011
    Messages:
    22,029
    Likes Received:
    9,544
    Location:
    US of A
    That is not what the thread was about.
     
    NewReligion likes this.
  19. Guitar-Rocker

    Guitar-Rocker Well-Known Member

    Joined:
    Mar 5, 2012
    Messages:
    2,723
    Likes Received:
    2,309
    Location:
    Indianapolis, Indiana
    With all due respect to Ken (which is a lot) there are some that desire that lower noise floor, however it is to be obtained. Granted at full volume, much of the intricacies are lost in the mix, but some of those intricacies still aid the final product
     
  20. Gunner64

    Gunner64 Well-Known Member Premium Member

    Joined:
    Nov 16, 2013
    Messages:
    4,839
    Likes Received:
    5,393
    Location:
    Midwest, USA
    Here's a question. Do the Guitar Amplifier companies install their caps with the correct correlation?

    All this isn't new information, but in the past I always remembered it to be always reserved for hi fi audiophile circles, and not as critical in guitar amps. And Once you add boost, od and/or other pedals, the noise floor usually takes a hit anyway right?

    Someone should install them all backwards, and then correctly in a build and compare just what the actual difference is.
     
    Biddlin likes this.

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice