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| Rick, your knowledge of amps/electronics is superb, |
I wish ! Still in the learning stage after 35+ years of "hobby" and the fact that I learn new things almost daily is what keeps it fresh and exciting.
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| where do you recommend I start reading to learn this stuff? |
Build build build and not just audio but
useful toys as well.I was very lucky in a way because there were a number of readily available electronic magazines when I was a youngster and I read them all avidly until some actual knowledge broke into my brain
Popular Electronics,Radio Electronics,Audio Magazine for the nuts and bolts of audio plus five or six I can't remeber the name of off hand.Every month something new to build and with the "this is how it works and why" part.All long gone but not forgotten by me and many others in my age group.
It mattered not that the "thing" was only a simple blinking light or a relay attached to a switch for "something" on and off and I would be hard pressed to actually find something useful to do with most of the projects i built back then but it was the build process from reading a schematic ,laying out the circuit using terminal strips and the controls as tie points or making home made heat sinks that counted.The learning and self toubleshooting the circuit was the important part and the "troubleshooting stage not the least of since a "typo" meant you either
knew why something did not work or spent a month blowing it up until the next months issue came out with the "oops ! We screwed it up ! Part B should have been postivie and not negative ! sorry !".
Today we have the internet and instant gratification,the ability to build damn near anything and have it work,plans available to build just about anything but the simple nuts and bolts projects that teach good electronics practice,the actual learning by doing is not there.
"Designs by committee" where you may accidently come up with something that works then everyone follows and builds the same .
Plug and play electronics that while WAY more sophisticated than any of my early efforts are no more than "kits" where you plug part A into slot B with very little in the way of the "why does this part do this and if I change it to X what then ?" because everyone is in love with the opamp or monolithic buffer and would be hard pressed to design a simple single transistor amplifying stage and not have it be an oscillator intead of amplifier.
I would start with the past and go straight to some of the early articles that got me going when i was thirteen and waiting for the next issue :
Popular Electronics projects online.Some may seem a bit dated and maybe even goofy in this day of high density SMD microchip but all those "minicircuits" on the substrate have an actual discrete base in their past before being miniaturized and many of the building blocks can be fouind here-
http://www.swtpc.com/mholley/Popular...lectronics.htm
Musical intrument and and hi-fi amps,control circuits,gadgets,color organs,test equipemnt,all broken down into the actual stages where you can actually "see" the why of it unlike the closed black box of the I.C. chip.
If you want to learn how to design an audio amp stage about the best information out there is by Dr.Leach.This article/project actually was in Audio Magazine in 1976 and unlike a simple "here it is,here are the PC boards,buy them and go build it" the text explains in detail the how and why of every single stage of the design.You don't need to build the amp to find the text OR parts of the amp (Hint-the front end makes a dandy nalanced/differential gain stage
) and explanations useful.
http://users.ece.gatech.edu/~mleach/...77articles.pdf
for a different take on power amp design this is a great text :
http://www.passdiy.com/pdf/A75p1.pdf
http://www.passdiy.com/pdf/a75p2.pdf
Or maybe class-A from the undisputed champion of.Not the recent single ended single device amps he designs,also cool but not applicable here, but a fully fleshed out "traditional" Class-A power amplifier suited to driving not only a wider range of loudspeakers than the SE designs but is the one I use to drive my Stax Transformer Interface/Stax Cans.Probably would make a kick a*s K1000 amp even with less parallel output devices and again, full blow by blow of the "why" certain choices are made :
http://www.passdiy.com/pdf/classa_amp.pdf
The reason for inclusion of these power amp designs for audio electronics understanding is because there are actual
discrete stages involved.A front end gain stage,a driving stage and an output stage and each can be useful when designing a headphone amp (for instance take it just to before the output and you have a headphone amp,just before the driver a preamp or discrete opamp !)
Actual discrete opamps ? how about the first "audio" opamp design published widely and a fully useable circuit as it is (from 1977 !) :
http://users.ece.gatech.edu/~mleach/...b77article.pdf
then move on to more refined discrete opamp designs but the important part is the WHY,the detailed explanations of each part :
The simple "you finish it to suit your needs,here is the loose outline" type design :
http://www.passdiy.com/pdf/diyopamp.pdf
to the fully finctional with total descriptions as to operational points :
http://www.forsselltech.com/JFET%20Opamp.PDF
and finally everything you ever wanted to know about designing with JFETS (and then some
) from the intput stage to biasing :
http://www.borbelyaudio.com/adobe/ae599bor.pdf
http://www.borbelyaudio.com/adobe/ae699bor.pdf
if you look at every single product/kit on this page
http://www.borbelyaudio.com/special_articles.asp you will see that the "building blocks" are all in the two files above so anything you want is there.
Rather than point you to tecnical texts or advanced electronics pages/content I personally beleive it is far more useful in the long run to do projects that you can actually use that teach the same principals as you build.Screwing up is part of it as is the troubleshooting stage but my opinion is you learn more by building from scratch,from a bare schematic with explanations (and maybe even at first failing) than you do by building a "kit" then looking for a wiring or soldering miscue.
With the above texts once you understand them you can conceivably begin to design your own audio stages to suit your own personal needs.All there man just a matter of implementing the content in real world situations
hope this helps answer the "how can I" question.the rest comes down to listening and keeping the parts that sound good while crap canning the parts that don't.
rickster
