Objective2 O2 Headphone amp

[danielphantom]

I can't believe all these people have read this and not commented--I have made this amp and it is now about 8 months old and it works great, have some grado 225's and use an ipod. Its a great feeling of accomplishment to make something that is so functional

[samwell7]

Looks pretty sick, I'm a 3rd year electrical engineering student this looks like it'd be fun as something to do over holidays,
how does it sound? How long did it take you to make?

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[danielphantom]

Originally Posted by samwell7

Looks pretty sick, I'm a 3rd year electrical engineering student this looks like it'd be fun as something to do over holidays,
how does it sound? How long did it take you to make?

Sent from my Galaxy Nexus using Tapatalk

I bought the parts from Mouser and a couple other places all listed in the BOM (bill of materials), and after getting everything together it took one day to plug and solder together. There are very meticulous instructions to follow and test as you go along. I didn't feel like I was rushing and it worked first time I tried it (amazing.) Make sure you read all his notes because you can upgrade sockets to gold plated if you like, trim part of the pot mounting feet to avoid a possible short etc...

It was a very enjoyable project.

I don't pretend to have measured it against anything else. I just know that I can listen to my headphones from the ipod and hear a real full sound--compared to before where I turned up the ipod all the way and it barely got loud enough--plus the sound was very thin.

There is no sound when you turn the amp on or off which means that its not throwing a big dc voltage during the turn on/turn off phase. I had originally built it with the 2 9volt batteries and occasionally would walk around with it, but now I took the batteries out and it just stays plugged in on my nightstand.

There is so much information that this NWavguy has written about you will probably enjoy going through it, I am a jr EE at heart and mess around with a variety of logic circuits and have a ball.

He is also working on a DAC that will be designed to fit into the O2 and that will require a custom back panel for the case but then I guess you can use it with your computer or what not to improve the sound coming out of that.

have fun,

Daniel

[samwell7]

That sounds like a perfect project for some time off, thanks for your honesty!
Will post in here when I get it done (probably still a couple of months away yet)

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[samwell7]

Ended up getting impatient and ordering a Pre-made one from JDS labs haha,
cost about $165 with shipping to AUS, very much looking forward to hearing it and seeing if it powers the AKG K702's I'm about to get

[danielphantom]

cool, let me know what you think--I got my circuit board and the faceplate all pre-made from JDS. Had to order the enclosure from Allied and then all the parts from Mouser.

So you got it all done in one shot Hope you like it

Daniel

[samwell7]

Just unpacked the amp now
Very happy with it, listening to The Unforgiven by Metallica atm and the presence is huge.
Not sure if this is what it would do but everything sounds more seperated now.
The bass is nicer now too, the headphones feel like they have enough juice behind them now to really crank.
only got the input signal at like 70%, got the amp on low-gain and about 33% of the way up and its plenty loud enough, don't think I'd really need to listen much louder to be honest.

Very happy with it! thanks for showing me this

[danielphantom]

Originally Posted by samwell7

Just unpacked the amp now
Very happy with it, listening to The Unforgiven by Metallica atm and the presence is huge.
Not sure if this is what it would do but everything sounds more seperated now.
The bass is nicer now too, the headphones feel like they have enough juice behind them now to really crank.
only got the input signal at like 70%, got the amp on low-gain and about 33% of the way up and its plenty loud enough, don't think I'd really need to listen much louder to be honest.

Very happy with it! thanks for showing me this

Hey, you're more than welcome, I don't listen to the high gain very much either--it really makes my headphones shine and I enjoy the full sound that it produces.

I forget if you're listening to ipod but if you hook your mp3 player through the dock instead of the headphone jack you will get a better audio signal to amplify

Daniel