rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on May 8, 2006 23:40:02 GMT
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rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on May 8, 2006 23:40:54 GMT
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rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on May 8, 2006 23:56:31 GMT
A "trend" is to mate Op-Amps with high bias AB or full Class-A output stages and the signs are everywhere. This is not a new thing but a very old technique used since the inception of the original Op-Amps (both the discrete Philbricks and later on monolithic devices) to get real drive power from the gain stage. The reason this is an apparent new thing to some is the recent years use of a buffer chip to perform the discrete stage duties and not because they are better but because they are EASIER to use and even a moron can tie one on to the output of an opamp and call it a "headphone amp". Full circle audio where the old timers figured out the best way to do a thing,the puppies come along and make it "better" because we all know anything new must be better than what went before then someone "discovers" the very thing they formerly called out of date crap. This is a good thing and it is only surprising to me sooo many took sooo long to discover what was under their nose the whole time
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Post by gns on May 10, 2006 3:07:37 GMT
I have to agree with Rick. It's the way we did it in the old days before they gave you the easy option. Take a look at the PDF. For you to do it discretely you need an understanding in transistor biasing, "miller-effect", thermal runaway, thermal drift in diodes, transistor SOAr (safe operating area), impedance matching, DC current matching, ......, etc. Not any old op-amp and transistor pair is going to work well or work at all. Then there's the other bits that you have to know about and add to make it hang-in-there. The beauty of the buffer chip is, as Rick says, any moron can do it. Why are there so many morons? You know, the guy who's reading this may be a moron in Electronic terms, and may be feeling a bit sad about his lot. The problem we have caused (WE meaning the Electronics industry, industry in general, progress, super-power governments, greedy shareholders, etc), is that we, in our rush for all things good, forgot to educate the next generation!!! How did we get to know what we do? The generation before us told us!!!! But we're too damn greedy and selfish to educate the young guy, AREN'T WE? So we couch around complaining about them destroying our (hey man that's really cool) lives with their boom-boom mobile discotheques destroying their hearing and any chance of us selling them anything that sounds good!!! No, I'm not having a go at you Rick - I'm having a real punch-up with society - the society of today - the SHIT society we're so bloody proud of. I for one apologize to the young people of today who don't have a chance in hell of learning a fraction of what we were taught or had the learning infrastructure to be able to glean it for ourselves. The society of the western world is so damn greedy and selfish that it has made it impossible for people like us to pass-on our talents to anyone (we have to work so darn hard on the Wicked Witch of the West's treadmill that there's no time to help you - productivity - productivity - productivity dear presidents and prime ministers!!!) - but for one saving grace - we have this forum. Thanks Mike - let's start putting it to good use (nobody else will). Graham.
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rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on May 10, 2006 4:50:30 GMT
can't punch any holes in that one ! Passion is the engine and if we lose that we lose all caring and my attitude is if i don't care enough about something to be passionate about it and weigh in with EXACTLY how i feel then I am wasting my time and would be better off doing something else because in the end I am not just wasting my time but the time of anyone reading the meaningless words on a screen " Thanks Mike - let's start putting it to good use (nobody else will)." Step A and seconded Step B is for the few who give a shit to keep things at least interesting enough for others to take notice and even if they do not agree at least give a good accounting as to why not LET THE GAMES BEGIN ! HUP !
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tomo
250+
DIY Supremo
Posts: 368
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Post by tomo on May 13, 2006 2:39:56 GMT
Yeah, That's true. One of my very very best headphone amp is made out of a factory-made evaluation board. (Plus it's a single opamp style LAN cable driver!) It's really hard to beat it. I think we feel ok people using opamps. What gets us real annoyed is questions like ... "What's pin layout for opamp so-so?" I am a hard-liner in having a small library of specification sheets and refer to them whenever in doubt. (I know there are erusive things, but pin-layout? It's written on the first page!) I am a moron. But I know I am a moron and keep a miniture "Merlin" under my desk. ... Everyone should too. Especially now with 100GB harddrives. Tomo P.S. I don't mind having miniture-rickster under my table, too. Do you come in a mailable package? With modern compression technology, I think you can fit into a shoe box.
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rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on May 13, 2006 4:27:34 GMT
I'm a bit over 6'3" so you would have to mash me down real good with a 12 pound sledge to get me in a box.A couple of well placed shots should do 'er
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