[Southwind]

I Have done a bit of research on the site and decided on the RE-262 + C421 for use with my iphone to listen to pop/techno

I Was reading up on amps and it says that the audio jack is already amplified and using an amp on it is useless as it would just amplify a badly amped signal, I was going to use it with the data port > audio jack adapter > amp  would this give me a clean direct signal from the iphone? 
 
Which is the better of the 2, the site says the OPA-2227 is the better choice, but what do you guys think?
 
What is a DAC? (Just a guess Digital audio converter?) What purpose does it serve? 
 
Also if you guys deem any of my decisions to not be the best for the price I am going to pay please don't hesitate to let me know!
 
Sorry for asking so many questions, I always deeply regret my decision after I buy something if it was not the best choice!
 
Thanks!!

 

[Rath1on]

Hey, I'll try and be of some help since your questions have yet to be addressed. 
 
Firstly, DAC stands for Digital to Analog Converter. The music processed by computing devices, such as an iPhone or computer, is digital. They are made of 1s and 0s called bits. Headphones and earbuds cannot use 1s and 0s to move their drivers to create sound, so you need a DAC to create an actual current or analog stream. Amps simply amplify this stream with voltage to give the listening device more power. 
 
If you're going to be using IEMs, I'm not sure that AMP is well suited. It has a lot of gain and seems more suited for higher impedance headphones. Someone who knows more than me in this subject may correct me, but I would do some research for an amp more suited for the RE-262s specifically.
 
If you're going to be using the Line Out port on the iPhone (I assumed that's what you meant by data port), you'll need a DAC and an AMP, since that will be digital. Something like the FiiO E7 or E17 (they are both DACs and AMPs) with the LOD (Line Out Dock) would do that. And since that wouldn't really cost more than using those amps purely as amps, the quality would be better, so that may be the best direction for you to take. Since the DACs on the FiiOs is likely better than the iPhones.
 
Do some more research. 

I hope this helps. 

 

[mikeaj]

I haven't tried these out, but based on specs these look like some of the last headphones on the planet to need an amp (aside from the fact that maybe the high performance will reveal potential issues with the DAC or amp).  It's got high, almost flat impedance, so it avoids significant output impedance interactions with everything and demands very little current from amplifiers; furthermore, it has medium sensitivity—sensitive enough to run readily off of a common portable device, yet not so sensitive that it will pick up a lot of noise/hiss from noisy sources.
http://www.innerfidelity.com/images/HiFiMANRE262.pdf
 
iPhone internal DAC and headphone amp are not that bad, honestly.  In fact, they're better than a lot of people think.  Just get the IEMs and enjoy.  Furthermore, it's not like you want or need a top-quality system to listen to most pop and techno recordings.  That's not a dig on the music itself but the producers / recording engineers / general market (which has much lower fidelity audio gear than something like RE-262).

 

[tzjin]

Sorry, some of the information above is incorrect.
 
Using the LOD with an iProduct bypasses the internal amp, but not the internal DAC. The LOD can go directly from the iProduct to the amplifier. Trying to plug it into another DAC will not work because the signal is already analog. Using an LOD is highly recommended to avoid double amping the signal (internal + external).
 
Many owners of the RE-262 have expressed that an amp really helps the IEM shine. I feel that the C421 will be more than powerful enough to drive them. To read more about the differences between the two versions, I suggest Clie_OS's recent excellent comparison between many portable amplifiers under $200. It is not necessary, especially if you have an iPhone 4/4s, but it is still recommended.
 
http://www.head-fi.org/t/620775/the-sub-200-portable-amps-shootout-11-8-amps-compared