Soldato
In 8 years of ownership I have never felt the need to change my 650's. That's not to say there arent better headphones that have more detail, or a stronger bottom end or wider sound stage, but the 650's just do everything so well.
I've just been sat here for 2 hours listening to all the lossless hi res music i can find. Just listening to music. Don't think I've done that since the early 90's.
Was quite taken by this.
Well as your main use is gaming it really boils down to whether you want to use virtual surround because if you do then you are pretty much stuck with using a sound card anyway as external DACs don't have this feature.
Your options would be:
1) keep the Soundblaster and plug the HD650s into it
2) Keep the sound blaster and connect it to an external DAC optically, which would retain the surround feature.
3) ditch the sound blaster and buy an external DAC & Amp, which would give you straight stereo only
4) ditch the sound blaster and get an Asus Xonar Essence STX which has a much stronger amp and higher spec DAC.
A stronger amp not only allows you to increase the volume but an amp capable of providing a higher output voltage will bring the HD650s to life as they can sound a little dull on a lower spec amp.
I personally took steps 3 and 4, using the STX for gaming and the external DAC & Amp for music to get the best of both worlds. It does mean spending more but to me the results justified the expenditure.
Something you will come up against rather quickly is the law of diminishing returns, in that as you move up the scale of DACs and amps, the improvement in sound quality becomes ever smaller until you get into the region of hyper-fi where all sorts of audiophile nonsense is spouted and none of it is verifiable via measurements.
I have a relatively low end system, a Schiit Vali DAC (£95), Schiit Magni 2 (£95) amp and Schiit Vali (£150 for v2) tube hybrid amp. For just a little more you could get a Chord Mojo, which is a world class DAC and amp in a tiny package - Ryan swears by his.
Does this sound better than my sound blaster Z? Yes it does, specially with the HD650 and my AKG K702 as the amp is able to provide a lot more power than the sound card and both of these headphones need more power in order to sound their best, volts in the case of the Sennheisers and amps in the case of the AKGs. Is the improvement in sound quality a "night and day" difference (I hate that term)? Nope, any differences are quite subtle and don't believe anyone who tells you different.
Same goes for the STX, it drives the HD650s a lot better than the sound blaster but the main thing you notice is how much easier it is to get LOUD, whereas sound quality differences will be quite small and subtle, such as sharper imaging, more realistic sound stage, etc but due to the extra voltage the STX gives you, you also get a cleaner, fuller sound.
So should you upgrade from your sound blaster? It's entirely up to you to be honest, you may be lucky and not have overly sensitive hearing, in which case there is little point in getting expensive equipment but on the other hand you could have very sensitive hearing which can mean an expensive future as you strive for better and better sound. The safest way is to try before you buy, either take your headphones to a store and try better DACs and amps or order from somewhere like Amazon that has a good, no quibble return policy. The point being that they are your ears and your hearing will be different to anybody else, so only you can make this decision - which is why so many posts on Head-fi finish with YMMV (your mileage may vary).
ps. probably 80~90% of the sound quality will come from the headphones themselves and as you have a very good pair, then you are off to a flying start. Also and this is very important, the HD650 scales like no other headphone, meaning that the better amp you use, the better they will sound, while a headphone like the Philips Fidelio X2 will plateau, meaning that after a point it just won't sound any better and you will be wasting your money trying to improve it.
....wow
My exact reaction when I went from UE6000, which I thought were good anyway, to the SoundMAGIC HP200's
Some say the HP200's have a very similar signature to the HD650 with a slightly brighter top end. I've never heard the HD650's so I can't comment
I thought my AD700's were good but in hearing stuff I haven't heard before. I redownloaded all my Radiohead collection in level 8 flac and it's so good. 3000kbps
650's need an OTL tube amp to shine you have to factor the cost of an amp in.
I certainly prefer my fidelio x1 over my 650's but I don't have a good otl amp or solid state amp the 650's are meant to scale upwards with amps but sound their best on an OTL like the expensive bottlehead crack.
A quibble about that statement. Yes, there is an impedance hump, but that hump is due to diaphragm resonance. You'll see the same sort of thing in speaker drivers too. Resonance, being what it is, means that the driver efficiency at and near those frequencies is much higher, so it doesn't need any more voltage there to reach the same SPL as other frequencies. In fact, if you were to look at the frequency response graph, which is measured using a constant voltage, but sweeping the frequency across the spectrum, you see an essentially flat response ("normal" response variations due to other factors notwithstanding, of course). If the higher impedance at the resonant frequencies required higher voltage, you'd be seeing a dip in the response there.
A good article on amplifier gain by NwAvGuy - who recommends using the lowest gain that will get the job done....
http://nwavguy.blogspot.com/2011/09/all-about-gain.html
it depends on how strong the signal is from the source, if you're getting a good strong 2v signal in then 2x is more than enough considering the HD600 only needs 2.3v.
I get a maximum of 1.5v from the modi 2 and the gain from the magni 2 is either x1.5 (3db) or x6 (15.6db) and I've been switching between the two and frankly I can't tell the difference except for the obvious volume difference, the bass is clean and strong with both.