Sennheiser HD 597 + Fiio e17

[...] Until now I've been very satisfied, but I feel it's time to change my headphones since the sound has started to decay a bit (less bass, highs are a bit rough, less power, etc.). [...]

uhh the headphone is decaying a bit?

There is a noticeable leap in quality in the 598s over the 555s.  I have the 598s and really love them, not so much the look though.  You'll probably have a much more significant improvement in quality just by upgrading your onboard with an amp/dac.  Fiio has some good entry level stuff; e17 is great and you can plug into pc/laptop but was meant for portability with its battery: ipod, iphone, etc.  I use the e10 which is meant to just be plugged into pc usb 24/7.

Have you removed the tape inside the 555 yet? The 555 and 595 should basically be the same, except that the 555 is nerfed.

If your 555 still works well, I'd say go for an amp before thinking about the 598.

Thanks for the replies.

About the sound decay, it might just be placebo, but in the past year the sound felt duller than usual and the range has also been smaller.

I've looked for Schiit Magni and Modi and they are priced £120 each in UK, and they both are not in stock. Are the DT880s better than HD555/HD598, and can they be driven by a £120 amp (the 600 ohm). I am seriously considering buying those, although I need to find a decent priced amp which is available.

And how do I connect the amp directly to the laptop if I don't have an external DAC? Sorry for the newbie questions.

Also, I haven't modded the HD555. I've read about the mod a while ago, but I was too afraid I would break the headphones. If I decide to go DAC+amp path, and the quality is better, I guess I can stick to the current headphones and upgrade to something better later.
 

Here's waht you should do to get better sound:

1. Change earpads.

2. Do the foam mod- It's very strairtforward buisness if you're careful.

3. if you still feel you're ready to take a quantum leap forward- Go for a better transducer. I recommend Beyerdynamic DT880s for your genres, I remeber upgrading from the HD595 and it was the proverbial "night and day" improvemnt across the board.

4. Upgrade your upstream eqipment, If you have an onboard card then go for a nice desktop amp first.

Good luck and sorry about you wallet.

About the sound decay, it might just be placebo, but in the past year the sound felt duller than usual and the range has also been smaller.

I've looked for Schiit Magni and Modi and they are priced £120 each in UK, and they both are not in stock. Are the DT880s better than HD555/HD598, and can they be driven by a £120 amp (the 600 ohm). I am seriously considering buying those, although I need to find a decent priced amp which is available.

And how do I connect the amp directly to the laptop if I don't have an external DAC? Sorry for the newbie questions.

Also, I haven't modded the HD555. I've read about the mod a while ago, but I was too afraid I would break the headphones. If I decide to go DAC+amp path, and the quality is better, I guess I can stick to the current headphones and upgrade to something better later.

I would say to get the Senn HD558's.

Remove the black rubber tape from inside the cups.

Get the Fiio E10 USB-DAC-Headphone amplifier.

I just did the foam mod. Was quite easy, don't know why I was scared I would break them. Anyway, I haven't noticed much difference in bass like most people claim, perhaps it's just a bit more focused. However, what I did notice was a better soundstage and treble. Especially treble is better defined than it used to be. My only concern is that treble sounds slightly harsh on some songs, but I'll have to adapt the eq. Overall impressed and I will keep the headphones modded.

I've decided I will keep the 555s for the time being. 558/598 sounds as an incremental upgrade and I would rather save for a better set of headphones. It's probably going to be hard to decide between HD650 and DT880. I've read most of the forum threads about those 2, but I'm still confused which one should I get. Any suggestions on which one would mix better with my music genres, and which one has better soundstage? I am also going to try and find both of them to listen to.

And would the Schiit Magni be able to drive HD650/DT880(600 ohm version) well? I've read people complain the 650s being hard to drive.

Thanks everyone for your help.

I, personally, don't think that the HD-598 is really a significant upgrade over the HD-555 at all.  In fact, my modified HD-555 is approximately in the range of 85% the performance of my new HD-600 headphones from Sennheiser.  I've done my fair share of thorough listening to many Sennheisers recently in order to be able to share some input into this area, so I'm not just talking from a paper statistic standpoint.

My HD-555 headphones, had the foam strips removed from the ear cups by the previous owner.  However, I then performed a slight mod variant that took them into a much better direction.  Inside the grill area, I placed about a 1" diamond of craft felt with an adhesive on the back.  This went into the area where the original foam pieces used to reside.  Then, within the cup surrounds, I applied a small layer of newplast, which worked to dampen the plastic that was present around the inside oval areas of the cups.  This really solidified the bass response.  I didn't add more bass, but increased the quality of it.