Trying To Take It All In

In order of influence on sound quality, transducer > amp > source  > cables.

So you should prioritize on spending money on a good pair of headphones, then find an amp that matches the needs of your phones (impedance, current and voltage capacity).

And then if you feel your current source is not up to its tasks change the source. And then cables if you have extra money to spend.

Mind you, this is only if your have "upgraded" your CD rips first. So re-ripping files actually takes priority over and amp/source upgrade.

On an IPod, there are three main supported formats, in order of sound quality mp3 < mp4/m4a/aac < alac.
With aac being slightly better than mp3 at equal bitrates, but with mp3 being a more ubiquitous format. Both are transparent in double blind testing above 256 kbps.

Alac is lossless, therefore being equl in quality to Aiff/wav files, ie the original CD.

As for an amp the headamp pico/ pico slim are both solid choices, but most portable amps don't come close to desktop versions at the same price.

I'd personally advise attention to the headphones and source first, followed by the amp.  I've had mixed results with portable amps when used with an iPod.  The results aren't as gratifying as they're made out to be here and with that I'll always stick my head out if the opportunity arises to be careful with that.  A great headphone will give huge returns to one's listening pleasure.  The next thing is the quality of the recordings themselves and the quality encodes... I recommend a minimum of 256Kbps since with great headphones you'll begin hearing issues with some of your music when encoded at 192Kbps.

So if you're looking at going in the cheap, then I highly recommend one of the more efficient pair of cans that do well without amp'ing.  If your headphones will need amp'ing then portable amp'ing is really a hit and miss thing.  Desktop amp'ing is far more likely to yield decent returns in terms of improved sound quality for money spent.

Koss PortaPros are indeed outstanding value. However, in my experience they do not benefit from amping, and can even sound worse that way. This can be good or bad, depending on whether you are looking to see what the fuss about amps is all about, or if you would rather keep things as simple as possible.

The ATH-M50 is another pair of headphones with great value. They have even lower impedance than the PortaPros, meaning they are just as easy to drive without an amp. But the M50 will benefit from amping. These are closed headphones, which are good for blocking out outside noise and stopping your music from leaking out (e.g. like in a library situation). They also fold up for transportation like the Koss ones. ~$100

ATH-AD700 is yet another bang for buck pair of headphones. Have not heard this one myself, but it has a reputation of having a nice soundstage and treble, but being lacking in the bass. cMoy Bass Boost you mentioned can fix that. Open headphones. Not the most portable, but great for FPS gaming. ~$88

If in-ear type of phones are an option for you, the Head-direct RE0 is a good choice too. And again, cMoy BB will be a good pairing in this case. ~$79

FiiO E1 is a headphone amp + Line out cable + iPod remote control all merged into one package. Quite inexpensive too. The amp draws its power from the iPod itself, so no extra batteries needed. Brilliant, in my opinion. Not head and shoulders improvement in sound over the iPod alone, but fully worth the price. Only works with Apple iPods/iPhones. Cable is kind of long, but there are ways to deal with that.. ~$20

At the entry level, don't buy an amp that costs much more than your headphones unless you intend to upgrade your headphones in the foreseeable future. Same with iMod. I don't think it would be worthwhile to pay for that unless you have a good amp and headphones already to be able to hear the improvements.

192kbps AAC/MP3 is fine for portable use. Chances are you won't be able to tell the difference between MP3 and CD quality unless you are actively listening for differences, and are familiar with the song being played, and are using higher end equipment in a quiet environment. Keep your music collection as it is, but opt for higher bitrate / lossless when getting new music. Then compare the lossless against MP3 yourself each time you upgrade your headphones. (And you will upgrade them if you hang out on head-fi, lol.) Only when you find that the MP3s sound bad should you replace them.

Quote:

Originally Posted by REDH0RN 

Thanks for the insight. I am kinda stuck with my current audio files for a while. Whole CD collection is stored in another state. I am almost positive I used 192kbs AAC which is a couple or few clicks above the 128 standard. My whole project has to be done on the cheap. For one my TiBook and it's 40GB drive will not allow larger files in it's current state. As far as headphones I am leaning toward the Koss Porta Pro's since they are purported to be an outstanding value. My main goal now is to have great portable sound for traveling and out-and-about. I have a pair of HD595's also in storage that will demand a solid desktop amp later. The JDS Labs Bass Boost cMoy v2.02 Headphone Amplifier seems like it would serve my purposes. With the boost circuit it should be a little more versatile than other low cost amps. I am however still in the amp and phones selection process. So many choices...

Quote:

Originally Posted by khaos974 

In order of influence on sound quality, transducer > amp > source  > cables.

 

I would say you've listed those in order of magnitude of typical distortion measurements but that's not the same thing as sound quality. Certain large distortions in transducers are harmless, while other tiny distortions in amps can be grating (like intermodulation distortion).

In my opinion, transducer, amp, and source are of equal importance. Cables debatable.

For a tight budget, I would put equal emphasis on transducer and amp, and say that an iPod or equivalent is a fine source.

No, I listed those in the order of what I actually hear, it just happens to be in the same order of typical distortion measurements. About the order, think of it this way, an HD650 or a Denon D5000 out of the headphone out of a laptop (pretty bad source + amp) would sound infinitely better than a pair of ibuds out of a beta 22 + DCS source.

By the way, intermodulation distortion happens with speakers too, even if the amp feeding them didn't have it.
 

Quote:

Originally Posted by mike1127 

I would say you've listed those in order of magnitude of typical distortion measurements but that's not the same thing as sound quality. Certain large distortions in transducers are harmless, while other tiny distortions in amps can be grating (like intermodulation distortion).

In my opinion, transducer, amp, and source are of equal importance. Cables debatable.

For a tight budget, I would put equal emphasis on transducer and amp, and say that an iPod or equivalent is a fine source.

Don't forget that nowadays many onboard sound cards measure well (enough for normal listening imho), unloaded anyway.

Transducers always (should) come first. I agree with khaos here.

Having been there, I would definitely worry about headphones first.  Don't worry about an amp just yet.  While I have one, for my low impedance headphones, it is very hard to hear a difference.  Anything from the linked thread will suit you just fine, including the Koss, which I find hard to beat for their cost.  Some headphones will sound different for the price, but not necessarily better.

http://www.head-fi.org/forum/thread/433318/shootout-45-portable-headphones-compared-aiwa-shellz-added-07-31

Go ahead and get Portapro.  Re-record your music, although, I am pretty happy with anything about 256.  I don't hear enough of a difference to warrant the extra space.  192 is decent as well, depending on the music.  Re-record one, or a few, of your favorite songs/albums and listen to it through 192, 256, 320, and alac.  See what you think about the differences yourself before uncompressing your music.  This will help you decide quality.  I agree with the above posts that cables give the lowest improvement.  I would argue that cables are mostly snake oil; they don't provide any discernable difference over anything less than 10 feet long, as long as they are working correctly.

Get yourself the cmoy, if and when budget allows.  If you hear a noticeable improvement in your Koss, more power to you.  If not, you've saved yourself from having to carry around additional equipment to hear your music.  The important thing in this hobby is to test things; have a healthy amount of objective curiosity.  Try things, and see how you like them.  Don't just do something because someone recommends it.  Obviously, this goes the same for what I say, but try it yourself.  If you buy a $600 cable to connect your source to your amplifier, and you hear a huge night and day difference, then who am I to stop you.  But, I contend that you don't need to jump in head-first to get amazing sound quality, and that you will get diminishing returns on your investment.  My AKG K450, unamped, which cost me $90, sound as good to me as my Ultrasone Pro 650 out of an Audio GD Sparrow ($250 headphones, plus $150 amp).

I think that Audio GD makes good value amps.  Overall, you shouldn't have to ask this question, as the topic has been beat to DEATH.  Go to the desktop amps section, and read read read.  Use the search function.  Anything that works well for the K701 should be fine for your K601.  I come from the camp that you shouldn't have to spend 5 times as much on the amp as the transducer.

For an RCA LOD, as long as it goes through the 30-pin line out plug, and not the headphone jack (which would make it something other than an LOD), it will be fine.  With a cable this short, and the voltage of the signal, even if the cable were 15 feet long, you wouldn't be able to hear a difference between the different brands.  Just go to ebay and get one for $13-$15.  Or, if it will be from home, just grab yourself an ipod dock, either from Apple or whatever 3rd party.  I am pretty sure that they all have a headphone out port, but check to make sure.

A turntable can be connected to your amp if it has the same connectors.  Nothing has to be placed between them.  It should be turntable-->amp--->headphones.