Analysing Power Amplifier circuits-General discussion

[fantabulous68]

My connection resets, so yes service does break and it is most annoying especially when I am almost done downloading something big and that happens ,
speed: 100Mbps
(I had dial up connection before, that was way worse....now I have adsl)
I am going to try again now...

 

[Nigel Goodwin]

My connection resets, so yes service does break and it is most annoying especially when I am almost done downloading something big and that happens ,
speed: 100Mbps
(I had dial up connection before, that was way worse....now I have adsl)
I am going to try again now...

Sorry, but that's not your speed

That's the ethernet speed between the modem and the ethernet card.

Here's a website you may also find helpful?

https://www.ampslab.com/projects.htm

 

[Hero999]

I tried downloading it MR Goodwin but it was corrupted and cant open up......................................

It worked for me in Adobe.

What OS are you using?

I've converted it to a low quality compressed monochrome multi page TIFF file and zipped it so hopefully you'll be able to read it.

The file is much smaller but it is lower quality.

I'm having problems uploading it, perhaps it's too big? I'll try hosting it somewhere else or splitting the file.

 

[fantabulous68]

i tried again... it cant download.

Sorry, but that's not your speed

LOL this is why i love forums, i can ask the silliest things and say the stupidest things without getting toooooooooooo embarrassed


Thanks for the new site, I will check it out now

 

[fantabulous68]

What OS are you using?

Microsoft XP professional version 2002

 

[Hero999]

Why not just download the latest version of Adobe Reader?

I've split it into two files.

You'll need to combine them both, before unzipping.

I've prepaired a batch file to help to if you're not familiar with the command line, rename combine.bat..txt to combine.bat, place in the same folder as the other files, click on it and the files will be combined automatically.

EDIT1:
This is a pain, the forum has automatically renamed the files which will break my batch file. I'll try shortening the file names bear with me.

EDIT2:
The forum renamed the files to ..zip which is still a pain but I modified the batch file so it won't be a problem.

I hope this is sorted now.

Download the files.
Rename combine..txt to combine.bat, run it and you'll be left with a zip file containing the TIFF file which can be extracted. You can then delete the other zip files.

EDIT3:
I find it funny how so many people have downloaded my attachments.

I suggest everyone try the link below before downloading them. Then if you have problems with the PDF, download the attachments. The PDF is better quality than my attachments which are monochrome TIFF files.
https://www.electro-tech-online.com...ate_guitar_amplifiers_teemu_kyttala_v10-1.pdf

 

[fantabulous68]

Wow Thanks alot Hero999. Got the book now

 

[BrownOut]

What are y'all talking about? I can't find any book to download. On the forum? On the site???

 

[Jony130]

What are y'all talking about? I can't find any book to download. On the forum? On the site???

Hmm, https://www.electro-tech-online.com/threads/the-guitar-amplifier-book-by-teemu-kyttälä.36605/

 

[BrownOut]

OK my bad. First, Nigel said "this forum" then later he said "books forum" Duh!

 

[unclejed613]

i seem to remember i posted a link to what is basically a tutorial on amplifier theory. please take the time to absorb some of it. right now you seem to be poking around in the dark, and keep poking yourself in the eye...

a working amplifier isn't made by taking bits and pieces and combining them blindly....

if you study modern amplifier design, you will find a striking similarity to the innards of an op amp. there are some very well thought out building blocks for both that work well together, and learning WHY and HOW they work and work together is a very interesting study.

for some reason you seem enamored with a design that shares some similarity to the Dynaco amp from the mid 60's. as good as the Dynaco amp was for it's time, it had it's limitations. those limitations sprang from the design having a single ended input stage, and the use of a single ended power supply. your latest "design" seems to be a rehash of the one before it, without addressing the questions that have been brought up about it. Audioguru, Nigel, and i have all asked you questions about various problems with the design you posted, and you keep on plowing forward without answering them.

 

[fantabulous68]

Audioguru, Nigel, and i have all asked you questions about various problems with the design you posted, and you keep on plowing forward without answering them.

I just read the thread again. I don't see any questions addressed to me from Audioguru, Nigel and you dealing with the various problems with the design I posted. I saw statements only.

 

[unclejed613]

you never addressed those problems.

1) compensation capacitance keeps the amplifier from becoming an oscillator

2) the amplifier design you have posted two copies of is missing some important components as well as being of an ancient design model which had many limitations.

you also are using a circuit that is over-complicated. Q1 and Q2 in your original circuit were a current source, which was then fed to a current mirror (Q6, Q&) to act as a current source load for Q9. you are using a single ended input stage with nonlinear negative feedback and a transistor connected as a diode to try to correct the nonlinear behavior.... the input stage design cannot cancel any nonlinearities of the input transistor and the input stage has half of the power supply ripple present at it's output. without a compensation cap the circuit will oscillate resulting in the output transistors as well as the driver transistors burnt. i will post this link again for you.... please read up on the subject...
**broken link removed** is where the following articles reside
**broken link removed**
**broken link removed**

they're a lot shorter than the book you're trying to download, and pretty much give you an idea of the WHY and HOW of amplifiers.

 

[fantabulous68]

the amplifier design you have posted two copies of is missing some important components as well as being of an ancient design model which had many limitations.

Sorry about that, i really am just starting to learn about amplifiers. I am not aware of which components are missing. Thanks for the links.......i will use them

 

[Bob Scott]

Looks rubbish to me?, and still VERY badly drawn, with no idication of which wires join and which don't.

Nigel and audioguru,

Why do you guys complain about the schematic style? I have seen this drawing style commonly used in hobby magazine magazine artwork back in the '70s.
There are no connection dots used.
All connections are purposely drawn as a "T" junction. They have 3 wire ends.
All crossovers look like an "X" and have no connection.
There is no ambiguity.

 

[Bob Scott]

for some reason you seem enamored with a design that shares some similarity to the Dynaco amp from the mid 60's. as good as the Dynaco amp was for it's time, it had it's limitations. those limitations sprang from the design having a single ended input stage, and the use of a single ended power supply.

Note that Dynaco was started by David Hafler. (look him up in Wikipedia for the full story https://en.wikipedia.org/wiki/David_Hafler ). David Hafler also started the Hafler company after Dynaco was sold. Hafler is a well noted maker of high end audio amps and kits, in the Dynaco tradition. You might say that Hafler evolved from Dynaco. Even if they no longer market consumer audio, you will find the Hafler co at https://hafler.com
Click on "Tech Support" and then "Library". You will find all of the old Hafler schematics and kit assembly instructions from the '70s and early '80s.

I point this out because you will see that these discrete designs (with a Dynaco pedigree) did indeed look like IC op-amps with differential inputs and dual power supplies. One example with instructions and schematic is the DH200, a 200 watt amp:
https://www.electro-tech-online.com/custompdfs/2010/03/DH-200_amp_man.pdf

 

[unclejed613]

i've seen it a lot and it does speed things up when drawing a schematic freehand. some people aren't used to it, and when the schematic has been through several generations of photocopy, it makes it difficult to read. i use it when drawing freehand, but the software i use uses dots for connections. it's similar to people using a single thickness line for a data bus, it gets confusing. i prefer a triple thickness line for data busses, it makes it easier to follow.

actually the first time i ever saw the simplified method of drawing schematics it was from an MIT grad. he was also very good at laying out the schematics so they were easy to read, so it worked well for him

 

[Nigel Goodwin]

Nigel and audioguru,

Why do you guys complain about the schematic style? I have seen this drawing style commonly used in hobby magazine magazine artwork back in the '70s.
There are no connection dots used.
All connections are purposely drawn as a "T" junction. They have 3 wire ends.
All crossovers look like an "X" and have no connection.
There is no ambiguity.

Old school perhaps, but what's wrong with making absolutely sure it's clear, random crossing lines certainly aren't.

 

[BrownOut]

I have absolutely no problem reading schematics in this style, as long as the style is consistant throughout the schematic. But.... I've seen some that are mixed style. Those should be burned immediatly.

 

[unclejed613]

i suppose it's like differences between drawing circles around transistors and vacuum tubes or not drawing them. the circles add a level of clarity to a schematic, but they're not absolutely necessary.

..or (but this seems to be more commonly a difference between Europe and America) drawing resistors as zigzags or rectangles.