[MiRaCL]

Hello

Been out of the whole headphone game for a year it seems. Still happy with my millett hybrid + 770 pro setup

Im now thinking of building a portable amp for use with my 770's (250ohms) and ipod touch..

Anyone got a diy portable amp to recommend?

 

[beer]

I like Mini3.
You can check it from AMB website:http://www.amb.org/audio/mini3/

 

[joneeboi]

There are loads of choices.

http://headwize.com/ubb/showpage.php?fnum=3&tid=6339

PIMETA, Mini3 get a lot of good press.

 

[nikongod]

a cmoy with an integrated silsose class ab buffer on the board. thats a worthy amp.

 

[Seaside]

You mean, sijosae's class AB amp?
I agree that's a worthy portable amp.

 

[jcx]

get ahead of the curve - build a portable balanced amp (its the easiest way to get the V those cans need anyway)

 

[MASantos]

Mini3 high performance version. The AD8397 has lots of output power for a portable amp.

 

[NelsonVandal]

Whatever you build, make sure to make room for an active ground channel, it's worth the effort.

 

[wui223]

Quote:

Originally Posted by NelsonVandal /img/forum/go_quote.gif Whatever you build, make sure to make room for an active ground channel, it's worth the effort.

active ground means?

 

[MiRaCL]

Thanks for all the answers. Im looking at the Mini m3 now, looks nice

 

[Yen]

Quote:

Originally Posted by wui223 /img/forum/go_quote.gif active ground means?

Means it's active, just like left and right channel...?-D

 

[NelsonVandal]

Quote:

Originally Posted by wui223 /img/forum/go_quote.gif active ground means?

The way used in LISAIII, PPA, PIMETA, Mini3, PINT etc - look at the schematics. You have a virtual/input ground (often by a TLE2426) and an output ground to sink the current from the headphones. Compare this to a simple voltage divider (resistors or TLE2426) and capacitors from positive and negative rail to ground, sinking the current from the headphones and acting as a virtual ground, as used in CMOY. I've found that the ground channel is equally, or almost, equally important as left/rigth channel.

If you care for a good sound (and I think we all do) this is the way to go in a battery powered amp.

But... is there a line out from iPod touch? Connecting an amp to headphones out, I doubt there will be any improvement amping high impedance phones like the DT770 mentioned above.

 

[wui223]

Quote:

Originally Posted by NelsonVandal /img/forum/go_quote.gif The way used in LISAIII, PPA, PIMETA, Mini3, PINT etc - look at the schematics. You have a virtual/input ground (often by a TLE2426) and an output ground to sink the current from the headphones. Compare this to a simple voltage divider (resistors or TLE2426) and capacitors from positive and negative rail to ground, sinking the current from the headphones and acting as a virtual ground, as used in CMOY. I've found that the ground channel is equally, or almost, equally important as left/rigth channel. If you care for a good sound (and I think we all do) this is the way to go in a battery powered amp. But... is there a line out from iPod touch? Connecting an amp to headphones out, I doubt there will be any improvement amping high impedance phones like the DT770 mentioned above.

Is the Sijosae classAB headphone amp has the active ground? since it use discrete buffer for the virtual ground part.

If my headphone amp (CMOY) uses wall mart regulated DC supply most of the time, is the active ground or virtual ground circuit contributes much to the sound?

 

[TzeYang]

nah, the Class AB uses conventional two channel. The discrete rail splitter is there to replace the TLE2426. By how it's implemented (caps after splitter) i'd say use TLE2426 instead of it. Size is smaller, current draw is much LOWER, and it probably sounds the same.