sfogg Posted February 26, 2004 Share Posted February 26, 2004 Craig, "Were talking about Amplifiers here not what tricks can be done with a cap out of circuit on a test bench." No, we have not been talking about a capacitor in an amplifier. We are talking about the AC coupling capacitor in your scope. " A good cap blocks all DC and when the amp is in its operating state warmed up as you would run the amp or test it THEY ARE CHARGE ALL THE TIME !!" No, it is not charged all the time. Look at you own pictures of the square wave signal you are inputing to the cap and show me where there is a continuous DC voltage flowing to keep the cap fully charged all the time. If you don't know what a continuous DC voltage looks like on the scope hook up a 'D' cell battery to your scope. Just in case...... make sure you set your scope to DC coupling. (Time passes) There is no continuous DC current flowing to that cap all the time when you are playing square waves. The DC component of the square wave flows positive for a little while, then negative, then positive, then negative. That is why depending upon the frequency of the square wave the cap is not always fully charged all the time and that is why it can pass DC. "All this mumbo jumbo is useless !" I'm sorry you think basic electronics is mumbo jumbo and useless..... Shawn Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 26, 2004 Author Share Posted February 26, 2004 Let me clear something up here. I don't think anyone that is truly involved in the technical aspect of this thread has attacked my work in anyway. I do still feel that the way Shawn worded things in the previous thread in a way that made it look like I was in some way trying to decieve people and yes I did take offense. I guess that was just a misunderstanding and all is fogiven. I have never said that I know the in and outs of the working of a scope , function generator or Audio amplifiers completely. My statements about the quality of my work are just trying to put across that this subject has nothing to do with it and I could go on for the rest of my life not understanding what is trying to be explained here and it wouldn't effect for the good or the bad how my work ends up. Others have tried to put across that it would in some way. I do feel that everytime I post some Square Waves certain people (there always the same) join in and start trouble put me on the defensive and the result is others end up getting the brunt of my frustration. If some of the people on this forum knew how the rest of the internet audio community viewed the Klipsch forum and SOME of its membership they would get a rude awakening fast ! I still stand by my question in a WORKING AMPLIFIER how could any DC component pass through it in anyway without raising havoc with the circuit ? The coupling caps in a operating amplifier are charged within seconds of the switch being turn on and in effect are blocking all DC. Craig Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 26, 2004 Author Share Posted February 26, 2004 Shawn the DC from the B+ in a amplifier charge the cap and its constant ! Craig Quote Link to comment Share on other sites More sharing options...
Painful Reality Posted February 26, 2004 Share Posted February 26, 2004 A Quality Cap that is doing its job correctly doesn't allow DC passed at least not in a measureable amount if it did it would induce distortion all by itself ! I suggest you do some more reading. Craig --------------- While this thread is going adrift... Craid, in a gigantic big fat nutshell: a low frequency square wave may be seen as DC for a cap. This explain the slope (filtering) on your signal square wave (from the generator). The slope is the cap charging since the cap will see 1/2 the period as DC. The lower the frequency the worst the filtering. Maybe this question will make you understand. You have a bad 100Hz square wave at the grid of your power tube but a good square wave at the plate of your driver/phase splitter (etc. depending of your amp). The plate is cap coupled to your grid. What's the first simple thing you'll do to try to improve the square wave shape at the grid? Quote Link to comment Share on other sites More sharing options...
alotaklipsch Posted February 26, 2004 Share Posted February 26, 2004 No man I"m FLKlipscher Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 26, 2004 Author Share Posted February 26, 2004 Shawn, I do not understand why you keep reverting back the this AC coupling of a scope subject. I could careless about AC coupling I am never using it for square waves again why should I they look better with DC and I wouldn't want to be accused of decieving anyone. But either way I could use AC or DC and get the same information for my own use. Craig Quote Link to comment Share on other sites More sharing options...
Guy Landau Posted February 26, 2004 Share Posted February 26, 2004 Call Mark. Quote Link to comment Share on other sites More sharing options...
alotaklipsch Posted February 26, 2004 Share Posted February 26, 2004 Call mark what? Quote Link to comment Share on other sites More sharing options...
Painful Reality Posted February 26, 2004 Share Posted February 26, 2004 ---------------- On 2/26/2004 3:18:42 PM NOSValves wrote: Shawn, I do not understand why you keep reverting back the this AC coupling of a scope subject. I could careless about AC coupling I am never using it for square waves again why should I they look better with DC and I wouldn't want to be accused of decieving anyone. But either way I could use AC or DC and get the same information for my own use. Craig ---------------- What Gerbache (much better than me) is explaining you is WHY is that AC coupling should be avoided at low frequency!!!! If you can't care less as wanting to know why (Hey! Who care's I just fix the damn things) then I rest my case. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 26, 2004 Author Share Posted February 26, 2004 Guy, I did !! I bet if Guy and a few others would leave this thread and let us that are truly interested in the topic that has involved here post and try to understand it would all come out in the end. Craig Quote Link to comment Share on other sites More sharing options...
Deang Posted February 26, 2004 Share Posted February 26, 2004 "You have a bad 100Hz square wave at the grid of your power tube but a good square wave at the plate of your driver/phase splitter (etc. depending of your amp). The plate is cap coupled to your grid. What's the first simple thing you'll do to try to improve the square wave shape at the grid?" Check the coupling caps to see if they are passing DC? Quote Link to comment Share on other sites More sharing options...
Parrot Posted February 26, 2004 Share Posted February 26, 2004 ---------------- On 2/26/2004 3:02:21 PM mobile homeless wrote: Paulparrot, you are the biggest troll on this entire forum (and the only one that posts with frequency). And your posts are downright slanderous. I see you as an extremely bitter person as you show little curiosity and even less willingness to see outside your A-Frame. I read Guy's posts and yours look cutting and crass in comparison. Actually, you seem to be the unhappy one (I will never forget your humorless, droll, bitter expression as you opened up your new speakers). After viewing that shot, I told myself never to respond to your rancor and baiting. But reading these latest offerings, really showed what you are made of. If anyone should be removed from the forum, it's you. You have posted more negative comments than any combined with very little positive influence, if you dont count the dog picture threads. Add in your alteregos such as FLKlipscher, and you have a monopoly on the bitter-end of the picture, both figuratively and literally. ---------------- Mobile, Please quit gazing at the photo-collage of me you have on your wall, okay? I would feel better. In virtually every post you've ever made on this forum you pronounce judgment, whether it be someone's wording of a message, the caps they use, the transformers they use, the music they listen to, or their expression. My question for you today is, Who do you think you are? Thank you, and enjoy the rest of your mooching day. Quote Link to comment Share on other sites More sharing options...
TBrennan Posted February 26, 2004 Share Posted February 26, 2004 Interesting watching other people wrangle. Craig, be cool buddy, you're getting a little Parhamish. Quote Link to comment Share on other sites More sharing options...
Parrot Posted February 26, 2004 Share Posted February 26, 2004 ---------------- On 2/26/2004 2:59:54 PM Guy Landau wrote: How exactly do you know what I do for living? I've earned every fr%$^&n single dime that I've made and never got any free meals. (but I don't need to report that to you). ---------------- Yeah, right. LOL! Quote Link to comment Share on other sites More sharing options...
Deang Posted February 26, 2004 Share Posted February 26, 2004 As in "Wayne"? Quote Link to comment Share on other sites More sharing options...
sfogg Posted February 26, 2004 Share Posted February 26, 2004 Craig, "But either way I could use AC or DC and get the same information for my own use." No you can't, at least not accuratly. Not if the amps distortion is lower then that introduced by the distortion from AC coupling. I know you are going to keep saying I'm watching the input and output and all that matters is the difference. I know you still don't see how that is incorrect but that doesn't change the fact that it is. What Marks illustration demonstrated (that I had explained pages ago), which you claimed to understand, was that first you are not looking at the input of the amp. You are seeing the output of the generator into your scopes first channel through a AC coupling filter (say filter 'A') that the amp doesn't see. The amp in effect is its own 'filter' (filter 'B') to the signal of the generator. Then you compare the output of the amp through another AC coupling filter (filter 'C') in your scope. Now what you are looking at is the signal from your scope on channel A through filter 'A'. On channel 'B' on your scope you are looking at the effects of filter 'B' and 'C'. I know you think the effects of 'B' and 'C' will be cumulative but they are not. If the effects of filter 'C' is higher then the effects of 'B' you will not see the effects of 'B'.... all you will see is the effects of filter 'C'. The only time you see what 'B' is doing is when its effects get greater then 'C'. " I do not understand why you keep reverting back the this AC coupling of a scope subject." Because that is what started this discussion. You still don't understand it, I'm trying to help you learn something new. Understand this might lead to understanding something else. The path of discovery can take you to all sorts of unexpected places and be a wonderful thing. Before you stand up and say "I don't get it" spend some time thinking about it and re-read this thread. Shawn Quote Link to comment Share on other sites More sharing options...
Painful Reality Posted February 26, 2004 Share Posted February 26, 2004 Interesting watching other people wrangle. Craig, be cool buddy, you're getting a little Parhamish. ---------------- Is Romy's best friend still around? The Pi forum disapeared from AA at one point. Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 26, 2004 Share Posted February 26, 2004 "...you're getting a little Parhamish" Damn Brennan...heh. Man, I havent seen that name in awhile. The good ole days... I miss the Parham Exchanges and his Russian bride. Almost brings a tear to my eye. The cap coupling blocks DC... But it also partly blocks (or filters) the square wave signals at low frequency as low frequency square waves will have the sufficient time to charge the cap. Perhaps this is off. The only scope I am around is my guitar friends and it's broken but makes the bench look important. Then again, these little guitar amps pass square waves that look like the Italy as viewed on a globe while on psilocybin. Is or is this NOT happening when doing a read? That's one answer that needs to be addressed. It seems so by the measurements. kh Quote Link to comment Share on other sites More sharing options...
Parrot Posted February 26, 2004 Share Posted February 26, 2004 Thanks for clarifying everything for us, Mobile. You wrote one of the standard reference books on circuit analysis, if I'm not mistaken? Quote Link to comment Share on other sites More sharing options...
TBrennan Posted February 26, 2004 Share Posted February 26, 2004 Painful---Parham started his own forum away from AA since nobody at AA would kiss his ***. Parham and 2 or 3 of his syncophantic pals ballwash each other over there. I feel good today, had a nice lunch. One of my pals took me to Magnum's steakhouse. Had grilled scallops and a salad and a 9 oz ribeye, medium rare. I'm enjoying retirement. Quote Link to comment Share on other sites More sharing options...
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