[Equus]

For your cd player, you should be able to plug M50's directly into most portables (and some component systems with output jacks).  You can insert a DAC, amplifier, or DAC/amp into the middle of the equation if you want to.  Same thing for the iPod and the laptop.  Turntable you do not need a DAC, but you will need some kind of amp or receiver.
 
With M50s, you don't really NEED any of the stuff in between (with the exception of the turntable setup), but can spend money on it if you want.  It all depends on if you're happy with what you're hearing.  Don't let someone else sell you on something that you don't think you really need with the belief it'll somehow turn all of your CD's into gold and give you the magical ability to fart rainbows.  For a rather large amount of people out there, iPod->headphones is more than enough to get them what they want.  I have a very good friend of mine who listened to my rig, acknowledged that it sounded much better than his iPod earbuds out of his Nano, but said that he didn't NEED his music to sound that good and that he was just fine and dandy with what he had.  Long story only slightly longer, for the headphones you are planning on getting, there's only so much you REALLY NEED.  If you want to buy more stuff and get "better" quality, fine.  Your gear, your ears, your decision. 

 

[ckunke002]

Thanks Equus! All great information!
 
What exactly does a "receiver" do in a turntable set up, and why do I need either that or an amp if I decide to get a TT?
 
And where you said "You can insert a DAC, amplifier, or DAC/amp into the middle of the equation if you want to.", I still don't understand why you would ever need to/benefit from putting a Digital to Analog/Audio converter in the middle of the setup. The source device already does the converting, and no matter how hard I try I can't comprehend the reason it would ever be useful to toss another DAC on top of the already audio signal.

 

[Equus]

I'm no expert at turntables (or any of the rest of this stuff, to be really honest...heh), but I think most aren't going to put out enough gain out to really power headphones at any real level...and I'm not sure how many would have a headphone output jack anyway.  Basically the amp/receiver is in there to boost the signal to your speakers or headphones or whatever so they have enough juice to make noises loud enough for you to hear and appreciate.
 
As for DACs, the only reason to have an external DAC if you already have something that has one in it (like an iPod and most transports nowadays) is if you A) are not satisfied with the quality or sound signature of the product's internal DAC, B) need additional gain or volume control to feed an amp or something else in the chain (kinda taking the place of a preamp), C) want to have multiple digital sources inputting into a single amp that lacks multiple input methods (assuming, of course, your DAC has multiple and selectable inputs), or D) want to spend money for giggles and prestige.  Again, all comes down to what you are happy with.  I'm not content with the built-in soundcard on my work laptop, so I use a portable DAC/amp at work.  I'm also not content with the onboard DAC on my Squeezebox Touch at home as far as feeding my amp, so I have an external DAC in between there.  Some folks don't hear much of a difference or even care about any difference in either of those rigs, which is just fine by me.  People look at me weird at work because I have this little black electronic box hooked up to my headphones and it doesn't have "iPod" written on it, which is also just fine by me.
 
Oh, and by the way, the DAC really only comes into play if you have a digital line out signal from your device.  i.e. it doesn't do any good for most mp3 players because many have no way of bypassing the DAC and outputting just a digital signal.  An example of how a DAC can be used is the SB Touch.  It has two different analog outputs (stereo coax and headphones) and two different digital outputs (coax and optical).  If I want to use an external DAC, I use the latter two outputs to feed the DAC, therefore (theoretically) bypassing the DAC in the SB Touch.  If I wanted to feed the SB Touch directly to an amp, I'd use the stereo analog coax output.  Hooking the DAC up to the analog outputs doesn't really do anything.

 

[sridhar3]

Quote:

That was a great explanation, and I really appreciate you taking the time to write it, but it still doesn't make sense why I would need a DAC for a source that is leaving an iPod/CD player. It has already been converted over to audio (or electric signal), so why does a DAC jump into this mix?
 
You had my following perfectly until at the end when you said in the chain we send source (CD/iPod) to a DAC.

So, a DAC can be implemented in one of two ways.  A DAC can be a box that sits on your desk, or it can just be a DAC chip inside a device.  Anything that has a headphone jack has a built-in DAC, as the device has to put out electrical current to move the transducer.
 
However, for a lot of people, built-in DAC chips leave a lot to be desired, as pertains to sound quality or signature.  So if you want to use a separate DAC, you need to figure out a way to bypass the internal DAC chip in the device itself, so you're putting out a digital signal.  You can then send that digital signal (via USB, coaxial or optical out) to a DAC box that sits on your desk.
 
Here's an example.  For people with an iPod, some people want to bypass the DAC chip that's built in.  So they get something like a Wadia 170i (link: http://www.wadia.com/products/transports/170i/).  When the iPod is docked in the Wadia transport, it can output digital data, which can then be sent to an external DAC.
 
If you need any further explanation, feel free to PM me.

 

[ckunke002]

Those were EXACTLY the answers I was looking for regarding why use a DAC after signal is sent from CD/iPod etc. I wasn't aware that you can bypass the amp/dac that's built into them. So I guess my question now is, how effective are amps without any interfering with DACs, and just running a CD player/iPod/laptop through an amp then to headphones?

 

[sridhar3]

Quote:

Those were EXACTLY the answers I was looking for regarding why use a DAC after signal is sent from CD/iPod etc. I wasn't aware that you can bypass the amp/dac that's built into them. So I guess my question now is, how effective are amps without any interfering with DACs, and just running a CD player/iPod/laptop through an amp then to headphones?

In general, amplifiers help.  They can increase soundstage, tighten up response and generally provide better clarity.  This, however, does depend on your headphones.  Some headphones, like Grados, are low impedance and high sensitivity, so they can be driven easily and do not need amplification (though Grado owners do report some small benefits to be gained from amplification).
 
In your case, Sennheiser HD 558 have a 50 ohm impedance, meaning they're harder to drive than Grados.  To be honest, I haven't listened to a pair of 558s, so I don't know to what degree they'll benefit from amplification, though I'm sure they will at least a bit.  I own the HD 650, which definitely needs amplification to sound its best, but that's a different animal altogether.  Hopefully somebody with 558s can comment.
 
Here's the part where I talk about stuff that doesn't pertain to your question.
 
A few other things to keep in mind:
-Garbage in, garbage out.  Hence, you'll gain the most benefits in sound quality from upgrading your source.  That is to say, if the files on your iPod and laptop are in low-bitrate mp3 format, it's not a bad idea to rip from CDs and get your collection in 320kbps mp3 or FLAC (or, in your case, ALAC, which is compatible with your iPod: http://en.wikipedia.org/wiki/Apple_Lossless).  CDs are awesome and have excellent sound quality, so no worry with those (but for the sake of convenience, it might not be a bad idea to rip them to a lossless format, FLAC/ALAC).
-The next most benefit you'll gain is from your headphones.  Upgrade your headphones first before you upgrade the other parts in your chain.  The only thing you'll have to be cognizant of when doing this is to make sure that you don't get headphones that require amplification to sound good, unless you're planning to also invest in an amplifier at the same time.
-After the source and the headphones, the next things that are important to upgrade are your amplifier, and then your DAC.  So, in order from most important to least important: source, headphones, amp, DAC.
-Despite this, however, it's important to note that your audio is the sum of all elements in your chain.  There is always the possibility that one of the elements can hold back the entire system - that is to say, the proverbial "weak link".  When you make your upgrades, always aim to eliminate the weak link in the chain.
-Tweaks like vacuum tubes (for tube-based amplifiers/DACs), cables, power components come at the very end.  Tube-rolling definitely has an effect on the sound, but it's a trial-and-error process to figure out which tubes suit your ears the best.  Cables and power components (line conditioners, etc.) have a questionable effect on sound.  To elaborate, some say they change the sound and others say they don't, and there are large contingents of individuals on both sides of the battle line.  In order to avoid inflaming people and starting yet another skirmish on this topic (and believe me, there have been many), let's just say the topic is controversial and hotly-debated.  At any rate, don't spend money on this stuff until much later.
-Trust your ears.  A lot of people will tell you a lot of things, but you're the final arbiter of auditory truth and justice.  Pick what you like and what works for you, because nobody can tell you that.
 
For your iPod, I'd look into these:
-http://en.wikipedia.org/wiki/Apple_Lossless
-http://redwineaudio.com/products/imod or http://www.whiplashaudio.com/personal-players/whiplash-audio-whipmod-upgrade-service.html (or there's a DIY mod that's similar, if you have the capacity to DIY)
-http://aloaudio.com/alo-audio-imod-cable-v2-lux-fep-18awg-occ.html (Note: This thing is mega expensive, and there are much cheaper versions of these floating around.  Keep an eye out for LODs.)
 
Whatever you end up planning on doing, figure out what you aim to get out of this experience.  You don't necessarily need to spend a lot of money to significantly improve your sound quality, but if you get sucked in there's a good chance you will end up spending a lot more than you initially wanted to.  Set budgets, don't spend outside your means, and don't be reckless.  If you have questions, always feel free to ask, and don't feel your questions are stupid or not worth the time.  This community is a vast resource, so use its existence to your advantage.  And if you can DIY, that's where you'll get the most bang for your buck, hands down.
 
I'm aware I've given you a lot of information above and beyond what you asked for, so feel free to ignore the stuff you feel is not relevant to you.  Whatever IS relevant, I hope it helps.
 
Welcome to Head-Fi, and sorry about your wallet!
 
Edit: Just reread a little bit and noticed you cancelled your Sennheiser HD 558 in favor of Audio-Technica ATH-M50.  They're easy to drive and don't need amplification, but will probably benefit marginally.

 

[Equus]

Quote:

 
Edit: Just reread a little bit and noticed you cancelled your Sennheiser HD 558 in favor of Audio-Technica ATH-M50.  They're easy to drive and don't need amplification, but will probably benefit marginally.

I had a longer reply ready, but for some reason it wasn't posting at all.  I agree with the above, and would say just try it out for a while with the M50 and see if you think you're missing anything.  I tried the M50 through different amps briefly at the last meet, and it didn't seem too sensitive to amplification.  Give your wallet a chance and see if you're happy with that.

 

[ckunke002]

Quote:

Quote:

In general, amplifiers help.  They can increase soundstage, tighten up response and generally provide better clarity.  This, however, does depend on your headphones.  Some headphones, like Grados, are low impedance and high sensitivity, so they can be driven easily and do not need amplification (though Grado owners do report some small benefits to be gained from amplification).
 
In your case, Sennheiser HD 558 have a 50 ohm impedance, meaning they're harder to drive than Grados.  To be honest, I haven't listened to a pair of 558s, so I don't know to what degree they'll benefit from amplification, though I'm sure they will at least a bit.  I own the HD 650, which definitely needs amplification to sound its best, but that's a different animal altogether.  Hopefully somebody with 558s can comment.
 
Here's the part where I talk about stuff that doesn't pertain to your question.
 
A few other things to keep in mind:
-Garbage in, garbage out.  Hence, you'll gain the most benefits in sound quality from upgrading your source.  That is to say, if the files on your iPod and laptop are in low-bitrate mp3 format, it's not a bad idea to rip from CDs and get your collection in 320kbps mp3 or FLAC (or, in your case, ALAC, which is compatible with your iPod: http://en.wikipedia.org/wiki/Apple_Lossless).  CDs are awesome and have excellent sound quality, so no worry with those (but for the sake of convenience, it might not be a bad idea to rip them to a lossless format, FLAC/ALAC).
-The next most benefit you'll gain is from your headphones.  Upgrade your headphones first before you upgrade the other parts in your chain.  The only thing you'll have to be cognizant of when doing this is to make sure that you don't get headphones that require amplification to sound good, unless you're planning to also invest in an amplifier at the same time.
-After the source and the headphones, the next things that are important to upgrade are your amplifier, and then your DAC.  So, in order from most important to least important: source, headphones, amp, DAC.
-Despite this, however, it's important to note that your audio is the sum of all elements in your chain.  There is always the possibility that one of the elements can hold back the entire system - that is to say, the proverbial "weak link".  When you make your upgrades, always aim to eliminate the weak link in the chain.
-Tweaks like vacuum tubes (for tube-based amplifiers/DACs), cables, power components come at the very end.  Tube-rolling definitely has an effect on the sound, but it's a trial-and-error process to figure out which tubes suit your ears the best.  Cables and power components (line conditioners, etc.) have a questionable effect on sound.  To elaborate, some say they change the sound and others say they don't, and there are large contingents of individuals on both sides of the battle line.  In order to avoid inflaming people and starting yet another skirmish on this topic (and believe me, there have been many), let's just say the topic is controversial and hotly-debated.  At any rate, don't spend money on this stuff until much later.
-Trust your ears.  A lot of people will tell you a lot of things, but you're the final arbiter of auditory truth and justice.  Pick what you like and what works for you, because nobody can tell you that.
 
For your iPod, I'd look into these:
-http://en.wikipedia.org/wiki/Apple_Lossless
-http://redwineaudio.com/products/imod or http://www.whiplashaudio.com/personal-players/whiplash-audio-whipmod-upgrade-service.html (or there's a DIY mod that's similar, if you have the capacity to DIY)
-http://aloaudio.com/alo-audio-imod-cable-v2-lux-fep-18awg-occ.html (Note: This thing is mega expensive, and there are much cheaper versions of these floating around.  Keep an eye out for LODs.)
 
Whatever you end up planning on doing, figure out what you aim to get out of this experience.  You don't necessarily need to spend a lot of money to significantly improve your sound quality, but if you get sucked in there's a good chance you will end up spending a lot more than you initially wanted to.  Set budgets, don't spend outside your means, and don't be reckless.  If you have questions, always feel free to ask, and don't feel your questions are stupid or not worth the time.  This community is a vast resource, so use its existence to your advantage.  And if you can DIY, that's where you'll get the most bang for your buck, hands down.
 
I'm aware I've given you a lot of information above and beyond what you asked for, so feel free to ignore the stuff you feel is not relevant to you.  Whatever IS relevant, I hope it helps.
 
Welcome to Head-Fi, and sorry about your wallet!
 
Edit: Just reread a little bit and noticed you cancelled your Sennheiser HD 558 in favor of Audio-Technica ATH-M50.  They're easy to drive and don't need amplification, but will probably benefit marginally.

Thank you for all this! I have learned a lot of this information over the past few months, seeking out ways to get the best audio possible, and basically deleting most of my itunes and reimporting the CD's i have back into it. I basically replaced all of my old low bitrate mp3s to 256 kbps AAC's (slightly lossy but definitely superior to mp3's in my opinion. I couldn't pick up much of a difference from the Apple lossless to AAC with my current headphones). My reason for doing this is mainly because I have no sense of how much space different types of files take up in my iTunes library. Do you guys know the real differences between Wav/Apple Lossless files that are full quality vs. most lossy files in terms of HD space used?
 
And I really appreciate all those links. Chances are, I will never drop 200 on an iPod mod though, especially considering I rarely listen to my iPod through headphones and when I use it in my car on rare occasion (I usually just use CD's), it sounds just fine to me. I'm picky, but I think iPods are overly bashed by high end audiophiles who nitpick at each little detail and like everything just perfect. I think if everything else is right, the iPod does the job (for me at least). Maybe that will change when I start getting some better stuff (lol).
 
I have a feeling though that with these M50's and full quality CD's and AAC files I'm going to be more than happy for the time being.
 
 

 

[ckunke002]

And thanks Equus!

 

[Equus]

You're welcome.
 
To be honest, unless the portable DAP has a line out, the sound is a compromise between quality, power, and size/weight anyway.  If you want serious music, I think you need a little more under the hood.  And while driving in a car, I really don't ask for much either.  If you think audiophiles and their home rigs are crazy, the lengths that some go to for their car audio is nuts.  There's so much noise and sound challenges in a car that you really have to make a concerted effort to get it above a certain point, and given I only spend at most an hour in my car on a trip most times, it really hasn't been a priority for me.

 

[ckunke002]

I actually have put pretty much all of my "audio" spending money into my car instead of headphones and such. I was just saying that I use CDs in it and rarely my iPod. I don't think car audio is too hard to work around, it's just another case of audiophiles never being happy with "great", it has to be "absolutely 100% perfect" lol. I don't spend all that much time driving either, but it's worth it to me to be able to jam out during those times (nothing better than a great song bumpin in the car system while breaking the speed limit dramatically.)