Suggestions for a stepup chip for battery powered headphone amp (from OPA134) anyone?

[Morse]

Hi everyone and thanks in advance for any suggestions or advice!

I'd like to toss together another point-to-point wired headphone amp, and am a bit bored with the OPA134. Suggestions on something that's a bit "better"? It had best be a moderate current draw type, since I plan to run it on batteries (for portable use). It should be able to power Sennheiser 600's without flinching, FWIW.

Just for reference, I'll probably tack on a crossfeed adaptor using carbon film resistors, and would like to use Elna Cerrafine or Black Gates as the coupling caps.

Preferable sound qualities (in the best of audio geek-speak tradition) would be "warm and engaging". Since this is a compact/low budget project, please don't suggest valves - I've already got several perfectly nice DIY valve amps (some for headphones) that just don't fit my requirements for small size. Anyway, this is a seriously low budget project!

Thanks again and all the best,
Morse

 

[digi01]

hi buddy,glad to see you again
for portable use,I think low quiescent current opamp plus solid stage buffer(class B,or class AB) is a good way.

wish it is helpful url

 

[tlmadsen]

Try some of ADSL-drivers that are around

Thomas

 

[Morse]

Thanks Digi01;

Glad to be back!

That's a very interesting link - many thanks! You've already inspired me to try my hand at a class B buffered chipamp (with the buffer inside the feedback loop). And you've given me a whole new forum to explore too....

Thanks Thomas;

ADSL? Any suggestions on "must have" chips of the series? Suppliers? Spec sheets (checked at Digikey and they didn't have much in the way of either the ADSL chips or info on 'em).

All the best and thanks again!
Morse

 

[sivan_and]

Try TDA2822 , One Watt Stereo Amp ICworks from 2.5 volts,3 volts typical...
http://www.st.com/stonline/books/ascii/docs/1462.htm
http://www.futurlec.com/Philips/TDA2822pr.shtml
Good luck !!

 

[dx.master]

Hi Sivan,

Try TDA2822 , One Watt Stereo Amp ICworks from 2.5 volts,3 volts typical...
http://www.st.com/stonline/books/ascii/docs/1462.htm
http://www.futurlec.com/Philips/TDA2822pr.shtml
Good luck !!

An externally hosted image should be here but it was not working when we last tested it.

If some one coudn't find or buy a TDA2822 (SGS) or aquivalent KA2209 (Samsung Semiconductor)
I can sold one or two over or Ebay or direct with or without PayPal, see the Infos on my Website:

- TDA2822M
- KA2209

The Website will change soon to http://akadns.de/ebay/?id=3&key=TDA2822M or KA2209

If you want to call me in Germany: +49.(0)2222-948-696956 (FreePhone)

all the best

 

[sklimek]

Hello Morse, you may want to check this out;
http://headwize.com/projects/showfile.php?file=kemhagen_prj.htm
A portable with crossfeed filter and P2P. Also Mahawk just finished offering his version of this with PCB's but w/ OPA627/BUF634 he may still have a couple, check this last post.http://www.diyaudio.com/forums/showthread.php?s=&threadid=40765&pagenumber=3

Best - Stan

 

[DaKi][er]

no one has linked to this, so i'll add it in

http://www.tangentsoft.net/audio/opamps.html

lots of info on opamps, how they sound, power conciderations for them as well

 

[Morse]

Thanks guys!!!

Checking through my odd's 'n ends bins, I see I've got some OPA 2228's that I could try. Other than that it's all OPA2134's, OPA134's, and a few dozen TL072's and TL082's.

Lots of ideas to work with both in your posts and at the links you provided. I can tell I'll be ordering up a variety of opamps from Digikey in the near future....

It was VERY interesting to read the reviews of different opamps at http://www.tangentsoft.net/audio/opamps.html since I use the Senn 570 and Senn 600 as my "good" 'phones - just like the author of that site.

Thanks again and
MERRY CHRISTMAS!!
Morse