I wanted to add the following: In case it helps anyone with a decision. They are now broken in. With a Forza Balanced rewire. I had the wires made of pure Silver and Pure Gold from Mundorf. My dedicated laptop is feeding a MSB Select DAC II, into a Woo Audio WA33 Elite/JPS. It seems that the k872 will scale to anything. The higher quality the frontend the better they sound. If there was better equipment to be had currently, I would not hesitate to provide it for the headphones. This is coincidently the best I have ever heard. I like it much better than the HE90,Shangri-LA,SR009. This is a fair comparison now I feel because even the headphones are only $1665.00, the electronics and all cabling comes to about $168,000 in my "little" system. Other than the K872 is dynamic and the others just mentioned are all electrostatic or planar-magnetic. That says a lot about the K872 right there.
More about the sound
:
Given the above circumstances, They went from a Mercedes to a Rolls Royce. The level of refinement and polish is true refence class. These could be used without second guessing to master any genre of multi platinum music. These are that versatile of a Chameleon as to offer accolades of justice to any music. Be it Tchaikovsky or Ted Nugent.
The background is ink black. Adding to this and helping tremendously is their very superior mechanical seal that has been implemented. The isolation is spectacular. The soundstage is now exactly as it is recorded. The dynamic range is exactly as recorded as well. Nothing is hyped or veiled. they are ruler flat. They do measure very well but they sound even more correct,natural,organic and polite. They are now very fast, however they never step on themselves or get ahead of themselves. They keep outstanding timing. The resolution opened up even more. These are precise in the manner of a surgeon's scalpel. Moreover, With a robust enough front end these will allow one to hear music exactly as it has been recorded. Be it great or poor recordings. These can and wills show you the Good, Bad and Ugly. Which is why many people dismiss these as rubbish. Either they find them too clinical and sterile. Well, that is one way of explaining heir sound signature. The proper explanation in that regard would be, that they do not beautify anything. What you have is what you get.
I know of no other headphones or loudspeakers for that matter that are this true to the source. They are highly resoling and exceptionally accurate. The other reason people may discount these headphones is not having enough of a front-end ahead of them. These were designed to be plugged into the finest Pro Audio equipment, such as Apogee, SSL and Avalone. Granted, them being so efficient they will play out of an Iphone. They will also sound considerably worse than DRE's Beats in that scenario. Quite frankly the finest DAPs could not possibly power them correctly. I would say as a rule of thumb, as a very entry level system with these it is really adamant that one invest in about a $2,500 DAC and $3-4K headphone amplifier for these. Otherwise they are just going to waste and you will most likely be another statistic complaining how much you despise them. I kept the Sony as well. A completely different animal. Very hyped and tuned. Does not care a lot about electronics. If you are reading this thinking gee those AKG's are truly horrible, the Sony may be right up your alley. I personally think the K872 with $168,000 of electronics ahead of it is the best I have ever heard. No one needs to spend that much but it will make usage of it indeed. It just keeps getting better up the food chain. I have tried so much electronics and headphones too. This was just my personal favorite. YMMV of course. At least I hope this provides a lot of information about the K872 in case anyone is researching it.