Whoever adviced me that Grado SR80i's do not need to be amped is a liar!

I think the problem is that a lot of people equate volume to quality.

Especially in phones like the Grados where the rudimentary nature of the driver is made up by it being much closer to the ear than many other more capable phones, and firing directly into your ear canal... and consequently sounding much more 'exciting'. In this case, with a relatively inefficient phone like the SR80 which can be driven to common-sense levels by most portable gear (but at the upper end of the volume scale), an amp can seem to make a major difference. However that aural assault might prove to be an issue down the line.

But try it like this:

- Buy an audio switch. A cheap one will do.

- Connect one input to the headphone socket, and the other to the amped output, and the common output to your phones.

- Switch to the headphone socket, set volume to reasonable listening level. Don't move the volume after this.

- Using something like RMAA on a PC - doesn't matter about the quality of the soundcard you're using it with - use the calibration part of RMAA to match the volumes of both outputs, using the headphone output as the baseline.

- Now while listening to music from the headphone, switch the output.

Grados sound good unamped, awesome when amped. :)

I think the advice is based on the margin of diminishing returns... 

Another victim of the Head-Fi 'carved in stone' phenomenon. Someone posts that Grados 'dont need an amp' and its repeated ad nauseam, often by people who have owned a pair of SR60s for a week, returned them and bought the M50. Lollygaggers, basically.

I started a thread a short time back asking how many have been deterred from buying a specific pair of headphones based on what they had read on Head-Fi - perhaps I should have broadened it to include sources and amps. Even my little iBasso T3 gave my Grados more air, extension and improved detail - I also find the bass tighter and punchier (no, thats not a contradiction) with an amp. Whether you can get good results with low impedance phones hooked to an amp designed for 600 ohm monsters is a question for someone else, but Grados definitely benefit from the portable amps I have owned.

I always recommend an amp to potential Grado buyers. I usually say that they don't need an amp, but they really want one. I can't stand to listen to my SR325's unamped.

Noobs and their "you dont need an amp for low impedance headphones" "advice" 

Glad to hear your enjoying the cans.

Sorry about your wallet :p

I would say that ipod is no good this way. You need something like Hifiman to drive big headphones.

And driving depends on more than dependence only, sensitivity does play an important role here. (You could refer to the tech specs of shure e5c)

Well,

1. Grados don't NEED an amp.

2. Every headphone sounds better with a good/descent amp.

3. Despite the virus-like pervasiveness of the ipod,the ipod is a poor source for anything.Highly overrated IMO.

4. "Need" is mostly a relative concept.

The source is mp3's *cringes* on an iPod created with the cheapest and smallest components by the lowest possible bidder in Taiwan and assembled by the lowest possible bidder in China and the concern is whether it sounds better with an additional amplifier stage?

I think I missed something along the way.

All else being equal, a different amp giving you more bass is due to less dampening of the transducers which means less control of those transducers which translates to sloppy response and less detail for your ears to revel in.

Brumagician99 said, "If im using my ipod i use ALAC which is apples version of FLAC."

Any "lossless" codec is better than mp3.  Still, I would have concerns about evaluating the merits of any piece of gear if an iPod is the start of the chain.

I'm no elitist but I do a lot of pro level work.  The iPod just doesn't pass the sniff test when they specify 20-20,000Hz response without bothering to specify a +/- range for it.  (The same as they do for their earbuds)  They don't even bother to specify a dynamic range or signal to noise ratio much less a distortion measurement.

When you are trying to evaluate which amp provides the balance that's right for you, it might be better to try an FM radio rather than an AM one.

Can an amp make a difference?

Absolutely.

Let's remember that you are testing the output of an amp whose input is connected to an iPod.  How is that iPod responding to the various loads that it's seeing? 

Is that headphone amp designed to handle the relatively high level/high current/very low impedance output from the iPod that was originally designed to drive speakers?

Those are just a few of the questions/concerns I have for the conclusions being arrived at.