[Morph91]

What cable do i need to connect the O2 amp to the STX? 
 
Here is a link to the amp, thanks in advance. 
 
http://epiphany-acoustics.co.uk/products-page/headphone-amplifiers/ehp-o2-portable-headphone-amplifier/

 

[Solrighal]

A link to the STX would probably be more useful.

 

[Morph91]

http://www.amazon.co.uk/ASUS-Xonar-Essence-STX-sound/dp/B001P9O894

 

[Solrighal]

I'm on my phone right now so it's difficult to see the O2 pics. If it's the normal O2 you'll need a cable with 2 x RCA phono plugs on one end (STX) & one 3.5mm male stereo plug on the other end (O2).

 

[Solrighal]

Something like this...

http://www.amazon.co.uk/gp/aw/d/B001KEVSX8/ref=mp_s_a_1_3?qid=1423827061&sr=8-3&pi=SL75&keywords=3.5mm+to+rca+cable

 

[Morph91]

I think it is the normal O2. I just didn't see many connections on the O2 so i felt confused for a minute, thank you for your reply

 

[Solrighal]

No problem. Have you actually bought the O2 yet?

 

[Morph91]

No i haven't yet. I had the EHP-O2D but returned it because i missed Dolby Headphone. I thought if i buy the O2 and connect it to the STX then i get a better amp and i don't lose Dolby Headphone.

 

[Solrighal]

Ah, that makes sense. I'm selling my Head'n'Hifi O2 if you're interested. It's the Desktop version with proper RCA inputs on the rear...

http://www.headnhifi.com/amplifiers/desktop-headphone-amplifiers/O2-desktop-amplifier

 

[Morph91]

Interesting. What is the difference between the one you're selling and this one in the following link..
 
http://epiphany-acoustics.co.uk/products-page/headphone-amplifiers/ehp-o2-portable-headphone-amplifier/

 

[Solrighal]

There's a couple of differences. On my O2 the power input is on the rear panel as opposed to the front. Having the power going into the front not only looks untidy but really can get in the way too.
 
Also on the rear panel are dual RCA inputs which hook up to your STX outputs and dual RCA outputs which allow it to be used as a pre-amp into a normal stereo amp (as you might use to power loudspeakers). My O2 has a full-size (6.3mm or 1/4") headphone output on the front.
 
My O2 has gains of 1x / 3x. I can't see anywhere on the Epiphany site a mention of what gains it ships with which is strange because that is important. I can only assume it's using the original design gains of 2.5x / 6.5x. That's way over the top unless you're driving some of the expensive planar headphones. !x drives my Sennheiser HD 650 easily and it's a relatively difficult load of 300 Ohms. £x is perfect for my AKG Q701's.
 
Here's a link to a couple of pictures of my O2 as well as my ODAC...
 
http://s1091.photobucket.com/user/heyzorro/media/Headphones/O2%20and%20ODAC/c413142a0d631e9e2d66a94f3c370ae8_zpsa7abc051.jpg.html
 
http://s1091.photobucket.com/user/heyzorro/media/Headphones/O2%20and%20ODAC/265dde32c344829e2e7ee685b71f7ec7_zpsfbf37b86.jpg.html