Probably not headphones if they want to squeeze out as much acoustic range as possible. Speaker Monitors will be the go-to. Of course they could use STAX...   But my knowledge ends there, and people will need to slot in with their own bits of brain power.   However in this thread our...

  That's far from a newbie set-up! Now you can fiddle around with the amp settings to find your audio nirvana.

  The O2 amp is a very very plain sound signature amp, that does this "plain'ness" in - probably - the best possible way in it's price range. It won't do anything different than most other amps, just very well (balanced-like sound, and almost invisible quiet noise floor). You already have a...

  Almost sounds like you had USB issues, considering that the ODAC Rev.b is designed to improve upon it's USB interface moreso than the choice of DAC chip.

  You may need something more powerful than the Xonar Essence ST. Silver version or Black version, the treble differences won't be enough to give you what you ultimately want.   That being said. The HD650 isn't known for being treble cannons, so jumping from a headphone which has them in any...

  It's not a "veil"! its a cashmere blanket and it's super comfortable!

  Since it's just switches that you can play around with, and no setting is permanent. The only good recommendation is to just play around until something sounds good.

Heavy amounts of current research on children has proven that the best scientific way to raise a child is to give it lots of hugs and attention. No. Seriously.   So I believe that the more we go into this topic, the more it's going to boil back down into "if it sounds good, then it's probably...

  Not to mention "speed".. I forgot what the term was, bit it had something to do with how fast the voltage/current (forgot which one as well) jumps back to nominal value after the volume reaches certain peaks/transients in recordings. I came across this when doing the O2 mod.

  I plug a tiny black box to my big black box. I plug a slightly bigger blue box - with a few dials attached - to the tiny black box. I finally plug my singing headband to the slightly bigger blue box, and singing headband starts singing.   This hobby is as complex as we allow it to be, and...

  I completely mitigated an important detail of my O2 which might be the reason why I sounded so eager to just slap a filter behind it: I forgot that my O2 is modded for boosted output, so my opinion of the O2 right now is skewed at best.   I don't have a stock O2 to compare to, but the...

  With the filtered Amp I'm using, which is in fact a far more rudimentary design than the O2, I've found the soundstaging and detailing to improve by a noticeable amount.   Thanks to that I have lead to believe that all amps do at least one of the following three things well:   filter the...

  If the filter is an active one, then most likely it's under very a similar design as the Kameleon or the active filter over at DIYAH. I'm still curious whether any design improvement/changes has been made, since the forums are currently quiet about the filters.   If it's redesigned to have...

  I use a HD650 with a DIY amp that's filtered purposefully to balance out the HD650 (increase sub bass and lower the mids a smidgen), and I have to say the sound coming out of it is amazing, but it still sounds like a HD650 regardless. Just a HD650 that has better controlled bass -and boy can...

  And those scars will have magnificent 5 O'clock shadows

  aha. I'm not even 30 and my ears are pretty much capped between 14-15k. I suffer from tinnitus though, which could be a contributing factor. You're doing great.

  Being a person that's from a product design background. I was conditioned to hate everything that philippe starck (yes low caps) scribbles out of his sharpie.   But the Parrot Zik may just be that only one exception... I still dislike that French designer though.

  Who are you, and what did you do to poor Matt and his Crack?   *edit: I realised how wrong this sounds out of context... but I'm keeping it this way*

  The O2 is a very "plain" amp, but does this "plain" in the best possible way for such a price point. So the question is more of what type of sound are you looking for?   As for sensitivity, do you mean how much power it requires? I ask this because the K712's are known to be pretty power...

  Whether those are stock pads or not, all HD650 pads have that plastic ring there to keep them in place when attached.   I also wash my pads once every month, and it's working pretty fine. I only use fabric conditioner to do so though.

  The foam pads can be removed by pulling on the pads, they're attached to a plastic ring which just grips/clips onto the headphone cups.     They are just as easily placed back in, just push them in on all "corners", and you should hear/feel a click on each of those corners.

  That's where ADGR's output booster board comes in.

Pay "that" much for a pair of headphones, and still need to mod it?   Something about it doesn't sit logically. Then again the lack of logic gives us great experiences here in this audio venture of ours.

I'd put it on a pedestal.

  Which probably means that the chipset on the DAC wasn't designed for phone use.   I have a Fiio e18 and it has a switch that allows you to select between PC input and Phone input.   Guess it's a price thing.