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o2 headphone amplifier

t0wer
O2 Amplifier

 

This amp was designed by nwavguy.


 

He doesn't make or sell the amps but they can be bought as a diy kit or fully assembled from https://www.mayflowerelectronics.com/ or http://www.jdslabs.com/

 

 

Build

I'm really not all too happy with the design of this amp.

 

DSCN1029_zpsc825f3ad.jpg

 

 

EVERYTHING is on the front.

(from left to right) power input, power switch, headphone output, led(that can't be left out > :( ), volume potentiometer, gain switch(I reversed it), and lastly the input.

 

 

 

Power Section

 

this can be used with batteries or ac power, but the batteries take up so much space it's extremely hard to reroute the input AND the power to the back, so I opted to not install some of the battery components and only run it off ac.

 

 

The power section of this amp is to the right/bottom of the red line.

This amp uses AC input not DC.

this layout really bothers me, I would have tried to get all the power components as close together in the bottom right as I could have, to avoid any interference caused from the AC input. It baffles me why it stretches all the way from the front to the back of the board.

Fortunately the AC section is all contained on the far right of the board, but rear power would have been nice.

4a86f790-5056-42a0-8c6e-0733bd536a30_zps

 

 

Sound

The power section worried me until I turned it on and turned it up.

Extremely low noise floor, my usb dacs have a higher noise floor(ymmv with usb, it depends on your system)

It may even beat out my m^3 amp which cost me a whole lot more.

 

The potentiometer caused some channel imbalance at low volumes. I think I would have preferred the use of an alps rk27 but those are HUGE in comparison to the small alps pot used.

Channel imbalance is a problem with any multi-channel pot, but with the low gain selected(gain is either 2.5x/6x for mine) I don't think anyone will be listening low enough for channel imbalance to be a problem.(or it could be I just got a lemon of a potentiometer)

 

For straight sound quality, I've not experienced anything out of the ordinary.

All of my amps have < 1ohm output impedance so they aren't causing any frequency response issues with my low impedance headphones.

It seems to be about as close to a 'wire with gain' as you can get.

For it's price it's excellent.

 

DSCN1026_zpsc1e4eeba.jpg

 

 

Final Thoughts

it's easily as clean as my other amps and if I wanted to change the sound to my liking I'd buy new headphones or use an eq.

 

It doesn't have room for multiple inputs or any eq options, but it amplifies a line signal for headphones and isn't that what you buy an amp for?

Will work for electronic components and parts


Reviews: Meelec CC51P - Monoprice 8323 - Koss Porta Pros  - Shure SRH-440 - Shure SRH-550DJShure SRH-840 - Hifiman He-500 - iBasso D4 - o2 Amplifier  -  SkeletonDac

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Built this myself using the schematics that is released as open source by the designer. Loved it ever since. Here's some picture.

 

post-5256-0-10379200-1387721726_thumb.jp

 

post-5256-0-46605800-1387722195_thumb.jp

The Internet is invented by cats. Why? Why else would it have so much cat videos?

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Do you have a part number? Curious :P

 

http://www.radioshack.com/product/index.jsp?productId=2104044&znt_campaign=Category_CMS&znt_source=CAT&znt_medium=RSCOM&znt_content=CT2032231

once I get my case printed, I won't use the strain relief and I'll just screw the jack directly into the case.

I don't think there aren't enough threads to secure it with a nut to one of your metal plates unfortunately.

but a 3d printed plastic plate should be fine.

 

and @Huntsman

that thing looks ridiculous

I like it 

Will work for electronic components and parts


Reviews: Meelec CC51P - Monoprice 8323 - Koss Porta Pros  - Shure SRH-440 - Shure SRH-550DJShure SRH-840 - Hifiman He-500 - iBasso D4 - o2 Amplifier  -  SkeletonDac

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Lol thanks. The only thing inside that I didnt make myself is the ODAC (from JDSLabs, no offence Mayflower). The rest is based off the O2 Amplifier by nwavguy. And yes, there are alot of ghetto things like the PCB for the USB B connector at the back and the cutting work for the main switch is real shitty. But the sound's what's important. Currently have it running off the ODAC, the twin 1/4 mono infront is Auxilliary input while the black 1/8 stereo is Line Out directly from the ODAC. The gain is 1x and 8x through changing some resistor values in the schematic.

The Internet is invented by cats. Why? Why else would it have so much cat videos?

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8x? What are you listening too man?

 

lol that is just in case i needed that kind of amplification.. im on 1x all the time. 

The Internet is invented by cats. Why? Why else would it have so much cat videos?

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See, a case like what Mr Huntsman has is all I want - but since I'm too lazy to make my own I just want to buy it.  :D

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See, a case like what Mr Huntsman has is all I want - but since I'm too lazy to make my own I just want to buy it.  :D

 

What's inside that you want?  :unsure:

The Internet is invented by cats. Why? Why else would it have so much cat videos?

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Mayflower I'm pretty sure is the only Seller who has the power jack on the back of the o2. That minimizes cable clutter to a good degree.

Selling my parts of my 900D rig for a jacked up Ncase M1. PM me for offers if interested (will take some reasonable-low offers because I'm desperate).

Parts that I'm selling: 900D (1 slot cover broken for stealth DVD drive mod) | Asus Z87 Deluxe | Cooler Master 212 Evo | Corsair 4x2GB black ram @1600mhz | EVGA 1000G2 PSU (2 cables with missing heat shrink) | DVD drive | HP membrane keyboard | Ducky Shine 3 YOTS in blue switches (warranty sticker broken)

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