[DrNope]

I'm using a set of Grado SR80 at work with a Little Dot II++ and a Denon 755 cd. Since I'm using it about 5hours a day I've started to notice that a lot of CDs, if not all, has a very high trebble which is killing my ears. I thought this was down to CDs being mastered with high average sound-level since this got worse with those records. I did however bring one CD home and it was not even distorting, well, not as much at least (Using MF A3 cd/preamp/power amp and a set of Dynaudio 1.3SE at home).
 
Is this due to tubes getting old (bought second-hand 2-3  years ago, meaning it's been on for about 2000-3000 hours as a guestimate since I got it)?
I've also read that Grados do rise the highs, if so, any idea what other headphones to try? Got the Grados because they sounded nice but mostly because they fit my ears very well. Would the SR225/325 perform smoother in the upper scales?

 

[Uncle Erik]

It could be that you're not well-suited to Grados.

The other problem could be the amp itself. I believe that your amp has an output impedance higher than the impedance of the Grados. When that happens, the low end gets weird and thrown out of balance.

You'd probably be better off with a solid state amp or a tube amp that has output transformers to lower the output impedance.

 

[elrod-tom]

My first reaction when I saw this was Grados don't always mix well with tubes.  As Uncle Erik said, impedance mismatch.  I used to have a MF X-Cans V2 that I loved, but mixed with my 225's it practically made my ears bleed.

 

[Frylock]

few things might be happening here. First, is that you are not suited to the grado sound as stated above. It's more focused on clarity and treble. You could try the 'tape mod' , putting electrical tape around the foam to soften up the treble and increase the bass. search for it here. 2nd is that grado sr80's dont need an amp i think. i plugged it into my mid-level onkyo reciever and it onlly emphasized on the parts i didnt like, mostly the treble. it's fine on my ipod and laptop.
you could try getting a denon d2000. it's supposed to pair well with those little dot amps u already have

 

[DrNope]

Borrowed a SS-amp (supposed to be good, about $300-ish) and this is not easy. At first it sounded so muffled, thick, no spark or glow at all. Hooked up the LD2++ again and it was as clear and nice as ever, but a bit fatigue after a while. From that I'd say the LD2++ is what I really want, just that sound is distorting slightly and my ears start to get tired after a while.
 
Returned to the SS-amp after 1hour or 2 and the muffled thick boring sound is gone, sounds just the same as the LD2++, slightly less precise soundstage perhaps, but it's not that bad. Another proof that you really need to let the amp heat up before auditioning things....
 
Hope I'll be able to audition a few other headphonse instead, don't think SR125/225/325 are any different? I also think my CD is limiting at the moment, when (if) the DAC I'm trying to buy arrives I'll try to listen to it through that one instead, a MF A3.24.