Capacitor type for simple headphone amp

[GianLorenzo]

Hi there,

I am putting together a simple headphone amp based on the MAX4299 IC 'typical circuit', and I am not sure what type of capacitors I should use. I have seen a few sites on the web that say aluminium electrolytic are best for 'audio applications', others that say tantalums are even better, but in the MAX4299 evaluation kit you can get from Maxim they use surface mount X5R ceramics for all but one of the caps.

Any suggestions? You can probably tell from the post that I am pretty new to this game, so I apologise if I have posted this in the wrong area or asked a question so stupid it doesn't even deserve an answer.

Peace out

Bernini

[jcx]

http://www6.head-fi.org/forums/showp...15&postcount=4

for the big output coupling caps non-polar Al electrolytics are the best choice for low distortion at reasonable size/cost, highest V rating you're willing to fit

the 1 uF bypass could be be X7R ceramic, some of the higer k materials are noticably piezoelectric, I might use film caps, esp for the bias bypass, metallized mylar is ok if you don't want to make room for polypropylene (physically smaller is better for bypass caps)

cruise this site for lots of info:
http://headwize.com/projects/index.htm

op amp projects ~ 1/2 way down
(many more pages, articles, diy forum...)

[GianLorenzo]

Thanks heaps for that!

Does anyone have any suggestions for the 220uF, 10uF and 0.1 uF bypass caps?

Also, it is going to be pretty hard for me to get hold of some 220uF non polar Al electrolytics, what sort of a difference do you think it would make if I used some 200uF ones instead?

Thanks again,

Bernini

p.s. the schematic I am working off is available here:

http://pdfserv.maxim-ic.com/en/ds/MAX4299EVKIT.pdf

[Geek]

Here's another good page:

http://members.aol.com/sbench102/caps.html