Amplfier testing tutorials please

[KyferEz]

I've done some searching... Maybe not enough, but I am not finding anything promising with the terms "audio amplifier test THD tutorial" (or other combinations of those words) on here or google and couldn't think of any other good search terms...

I digress. Anyway, could someone please point me to one or two *good* tutorials on testing an amplifier for THD, RMS and Peak power output, signal to noise ratio, frequency response, etc. I'm looking to test some amps I have and find out what they *really* do.

Thanks,
KyferEz

 

[jcx]

http://ap.com/library/books.htm

you have to register to download but there is some good stuff spread around the AP site

analog.com, national.com, linear.com. ti.com all have app notes and design guides and some video brodcasts on electronic design, prototyping and measurement

 

[KyferEz]

Thanks for that. I've been reading a lot, but I really need a simpler measurement tutorial. I understand some of the things I've asked about measuring is complicated, so I'll start with whatever is simpler, and work my way from there.

I'm not looking to have to buy a bunch of expensive equipment either. I would like to do the tests with what I have:

200MHz PC-based oscilloscope (sds-200) which also is a frequency analyzer.
Power resistors
Multimeters
PC software used for frequency generator

Thanks,
KyferEz

 

[jcx]

for audio frequency measurements your pc sound card has much higher resolution than any pc 'scope I know of

of course a decent sound card like the $150 ESI Juli@ betters any motherboard card

check out:

http://audio.rightmark.org/index_new.shtml

the fast 'scope is still invaluable in debugging, veriftying stability, slew rate limiting, ...

 

[KyferEz]

I read the entire manual for RightMark, downloaded the software, ran it, and am embarrassingly clueless...

Isn't there any good tutorial written to show how to hook up the amp to the sound card, and then step-by-step explanation of how to use the software and understand what it's doing?

This kind of stuff always drives me crazy until I can have it explained step-by-step: how to do the step, and what that step is for.

Thanks

PS I'm a microcontroller kind of guy; this analog stuff isn't my forte, but I want to learn it!

 

[ppfred]

Hi,
These 2 sites are really great.
The first is a free electronics tutorial:
http://www.bcae1.com/
which does cover some of what your looking for.

The other one is a repair tutorial:
http://www.bcae1.com/repairtutorialcdinfo.htm
which you have to buy but it has everything you need. I purchased the CD and it is excellent with simulated ccts, instrument uses and connections, flash presentations and easy to understand explanations.
The author deals only with car amps, but an amp is an amp....

Also you can download a user manual and/or a tutorial from some of the oscilliscope manufacturers. They have excellent articles on how to make measurements and how to interpert them.

Hope this helps.
fred p.

 

[KyferEz]

Thanks guys. I went back and re-read the RightMark manual this morning. I think I've figured it out now. I must have been too tired last night and not understanding what I was reading...