human hearing

[IanHarvey]

To Ian (post #100)

However, any cirsuit with a feed-back loop can oscillate, provided that there is more than unity gain at resonance frequency. This does not depend on input LF filtering, but solely on the nature of phase lags and feed-back loops. Hence, I disregard the input LF filter, as most (proper) designs will be able to do without it.

I'm not disagreeing, but if you don't impose an HF limit with some nice, linear, input filter, the actual limit will be when the amp runs out of (open-loop) gain. Obviously, when this happens you have no NFB, so it could look pretty nasty.

If your gear is well designed, you will not apply HF signals ( >> 20 kHz) to an amp input, which makes the input LF filter somewhat academic if the rest is designed appropriately).

...and if the user is not stupid, doesn't use a mobile phone, has perfect cables, etc. In such an ideal world, you could also calculate your stability margins assuming the load was an 8 ohm resistor.

Cheers
IH

 

[sss]

Thats one of reasons for going ahead. After all, the technology behind the CD is already a quarter of a century old !!
Regards
Charles

yup
today we got our phono freaks , 10 years from now we'll have our "compact disc" freaks 🙂

 

[purplepeople]

Infrasound

Just saw this today...

http://asia.reuters.com/newsArticle.jhtml?type=scienceNews&storyID=3401200

Audible might be 20-20K but "sound" may be a much wider range.

🙂ensen

 

[sss]

we kney that 🙂