[8TrackTed]

I happened to arrive here while trying to find specs for my KOSS PRO 4AAA+ headphones, which much to my very recent surprise still work on both channels - after years of believing one was flaky (ie had a bad connection resulting in sporadic performance on that side) until it finally dawned on me to unplug it from the coiled extension cord and plug it directly into my receiver so now I'm going to give them a dozen or so tests I downloaded from http://www.audiocheck.net/soundtests_headphones.php,in addition to seeing (well hearing actually) how some of my CDs (classical and R&R mostly) sound in them. I'm curious to see how these "digital ready" headphones perform after all these years... after buying an iPod many years ago I started using lightweight headphones and earbuds and pretty much forgot all about the much better albeit much heavier and bigger KOSS PRO 4AAA+ headphones - which are at least  about 18 yrs old now (assuming they haven't been made since 1986 if I recall correctly)
 
They actually sound pretty good after all the years of neglect ... however  I'm tempted to  invest in another pair of cheap, but much more up-to-date headphones such as the Superlux HD 668B (circa $40) or not-so-cheap KOSS PRO-4AAs (circa $90)..if anyone's still awake out there after plowing through my semi-coherent prose what headphones would you recommend  (for under $100) as a companion to, or replacement for my good old KOSS headphones?

 

[GREQ]

I wouldn't worry about nonsensical marketing jargon like "Digital Ready" headphones - as most headphones only receive an analogue signal.
That's marketing rubbish from the 90's.
 
The Pro-4AAA's have quite a dark sound with a lot of physical sound pressure.
If you want something that sounds similar I'm thinking a Sennheiser would be a good replacement. You won't get the same feeling of sound pressure, but the generally darker signature should be to your liking.
HD429 or HD449 (if you can find it for cheap) should be to your liking.
 
Those Superlux headphones are A LOT brighter than the Pro-4AAA's and might not be to your liking. Then again, they've got bucket loads more soundstage and detail than the Koss, so you might like to try something new. 
The Presonus HD7 (another K240 clone like the Superlux) is also worth looking at. Slightly better than the Superlux apparently, and after you put some AKG velours on, it performs in some ways like a $200 headphone.

 

[8TrackTed]

Greq thanks for your input.  I seem to recall that when music first came out on  CDs one of the major objections from the Luddites*, er, LP lovers, was that CDs were "too bright" compared to LPs but since they sounded better to me I'm even more encouraged by your comments to buy the Superlux HD 668B headphones (which you described as being "a lot brighter" than my KOSS headphones) especially since the price is right and I'm currently on a tight budget. If I was on a looser budget instead of a loser budget, (pardon the pun) I'd seriously consider buying the Grado-SR225i Headphones: http://reviews.cnet.com/headphones/grado-sr225i/4505-7877_7-33801805.html
 
BTW I was never worried about the "Digital Ready" tag that you correctly classified as "marketing rubbish"  but in this case I thought it was rather charming albeit nonsensical - how do headphones or anything else become "Digital Ready" anyway? Only your ad-writer knows for sure...
 
* Yeah I know this is a mean (and probably inaccurate) way to describe audiophiles who still prefer listening to LPs but tact was never was one of my strong points

 

[GREQ]

If budget can be stretched, a Grado SR80i with medium size bowl pads upgrade, is about 90-95% of the SR225i.

 

[Claritas]

  If budget can be stretched, a Grado SR80i with medium size bowl pads upgrade, is about 90-95% of the SR225i.

 
Or an SR225i with S-cushions is 110% of stock SR80i. (Couldn't resist using the ridiculous expression "110%" for something actually correct. Sorry. But you're right, GREQ.)
 
OP, you'll have to mod the headband with foam or something because it's very thin.