[Turbo AL]

  OTL stands for Output Transformer Less.  Usually refers to an all-tube design like the Schiit Valhalla 2 and many others that use only tubes for amplification.  They have a higher output impedance than other amps do and also put out more power into higher impedance cans, so they're usually made for those types of headphones.
 
Hybrid of course, means it uses both one or more tubes along with solid state parts for amplification.  Kinda like a hybrid car uses both a gas engine and an electric motor.  Hybrid amps usually have a low output impedance and play well with low impedance headphones.  Vali 2 does very well with the M50x and Shure SE-215, but those don't sound as good as the K7XX so they're my portable pairs.  

So if the K7XX is at 62 ohms would you call that high or medium resistance?  Where do all solid state amps work best?  I see that the power drops off on them as the resistance goes up pretty quickly but tubes seem to be the opposite and I don't know about the hybrids?  Someone on the Massdrop discussion said that a hybrid would be best for the K7XX but it doesn't sound like it needs to be any warner, it sounds like it is just barely to the warm side to me.

 

[Murphity]

Yeah, I take back everything I've said about these. Now that I actually listen for a good amount of time, they're not that cold (not sure I'd say warm, but it's a weird feeling). They're really bass heavy, but it seems kinda heavy handed. It's like a slightly "wub" type bass. Female vocals sound gorgeous though, but mids are kinda weird. Maybe it's the burn in time? Or maybe the Fiio E18?

 

[kman1211]

  Yeah, I take back everything I've said about these. Now that I actually listen for a good amount of time, they're not that cold (not sure I'd say warm, but it's a weird feeling). They're really bass heavy, but it seems kinda heavy handed. It's like a slightly "wub" type bass. Female vocals sound gorgeous though, but mids are kinda weird. Maybe it's the burn in time? Or maybe the Fiio E18?

I found AKGs need extended listening time to fully grasp their sound, a bit of burn-in does help them warm up a bit. It's a combination of brain burn-in and actual burn-in. AKGs are weird though, but it's how different they are compared to other headphones that I like so much about them. I think it has to do with the varimotion drivers is why they sound so different.

 

[superjawes]

So if the K7XX is at 62 ohms would you call that high or medium resistance?  Where do all solid state amps work best?  I see that the power drops off on them as the resistance goes up pretty quickly but tubes seem to be the opposite and I don't know about the hybrids?  Someone on the Massdrop discussion said that a hybrid would be best for the K7XX but it doesn't sound like it needs to be any warner, it sounds like it is just barely to the warm side to me.

Solid state amps tend to have power dropoffs because they are voltage limited, while tube amps tend to offer a lot more voltage at the expense of current limits. Note, however, that these are tendencies and are not firm rules. With a different circuit design, one could greatly increase the voltage limit of a SS amp. Using a tube hybrid design could greatly boost the current limit as well.

For headphones, 62 Ohms can still be considered low for all intents and purposes. Basically, "high impedance" is 200 Ohms or more because the driver is specifically intended to accept a big voltage swing from an amp. What you want to understand from the K7XX's impedance is that--compared to a high impedance can like the HD600--it wants more current, so you really just want to avoid amps designed specifically for high impedance headphones.

 

[cel4145]

This is true for any new headphones.

I found AKGs need extended listening time to fully grasp their sound, a bit of burn-in does help them warm up a bit. It's a combination of brain burn-in and actual burn-in. AKGs are weird though, but it's how different they are compared to other headphones that I like so much about them. I think it has to do with the varimotion drivers is why they sound so different.

+1

This is so important. Regardless of physical burn in, when coming to a new sound, it does take a while for the brain to adjust. Particularly when one keeps listening to another pair of headphones that they are already familiar with that have a different sound. Try reading speaker reviews from some of the more well know audio magazines, and you'll find speaker reviewers talking about taking time to get familiar with a speaker. I think people here often rush to judgement without realizing how necessary psychological adjustment to a different sounding headphone is.

 

[cel4145]

Should I get the vali 2 then? I don't know what otl is but I don't see it in the schiit website so I'm guessing it's not otl. Also according to schiit logic their stuff is better than the other stuff our there that costs 6 times the price, so the vali 2 should easily be the best tube amo under a thousand xD (lol jk)

But SRS, idk what otl is, I googled it and read a bunch of articles, but I still don't know what otl is.. But I guess I don't want the otl?

I like the idea of vali 2 cus I don't want to spend a ton of Money on something that I don't notice a difference with again, and I like the idea of having one tube to worry about rather than like 50.

Would the vali 2 give me that vintage sound since it's not olt? What tube should I use with it?

I would suggest slowing down. You just got the NFB-11 less than 48 hours ago and you already have an ODAC/O2. Give yourself a chance to adjust to the NFB-11 and wait until you get the K7XX before making a decision. Don't count on DACs/amps to make a big difference in sound. If you want warmer sound from your speakers, then the best bet is to buy warmer speakers.

 

[superjawes]

+1

This is so important. Regardless of physical burn in, when coming to a new sound, it does take a while for the brain to adjust. Particularly when one keeps listening to another pair of headphones that they are already familiar with that have a different sound. Try reading speaker reviews from some of the more well know audio magazines, and you'll find speaker reviewers talking about taking time to get familiar with a speaker. I think people here often rush to judgement without realizing how necessary psychological adjustment to a different sounding headphone is.

To be honest, I'm still in a honeymoon period on the K7XX's comfort, and that probably colors my opinion of how they sound. I can definitely say that they sound "good", and are at least comparable to my HD600, but I am still going to need more time to pick out which is more detailed, how the K7XX's response feels, and whether or not I prefer the signature over the HD600. On top of all of that, I still have a Schiit Valhalla that I enjoy warming up from time to time with the HD600, and then I have multiple pairings to compare.

Psychological burn-in is a helluva drug. Heck, think about how you treat your vehicles. When you first start driving a new car, everything is wonderful (or almost everything). After a few months, you might notice some details that you want to get fixed. After a few years, you're looking at everything that your current vehicle is lacking and planning out your next car purchase...I may or may not be in this exact position right now.

 

[DavidA]

It depends on how you listen and other factors to say that there is psychological / brain burn-in, for me I don't listen to any single headphone long enough to get used to its sound signature, good or bad, who knows.
 
Never had a honeymoon period with any of my headphones, K7XX included since I've kept most of the headphones that I've bought and rarely listen to any one for more that an hour. I just like switching around a lot, I often listening to the same few songs with different headphones and may even switch the DAC or amp also, just to hear the different presentation.
 
Even when I'm on the plane I have 2 or sometimes 3 headphones with me.

 

[MtnMan307]

Now I'm wondering what kind of portable closed headphone sounds like the K7xx. I like the portability and build quality of my M50x, and they sound all right, but nothing like the K7 in most respects.

 

[cel4145]

Now I'm wondering what kind of portable closed headphone sounds like the K7xx.

Most of us would like to know that because I don't think it exists

I like the portability and build quality of my M50x, and they sound all right, but nothing like the K7 in most respects.

I have the NAD HP50s. Definitely better sounding than the M50 series, but a bit darker than the K7XX with less soundstage (of course). Decent for portability (they lay flat in a soft case). Very easy to drive so works well on portable devices. Sometimes good deals pop up for slightly used on the forums here. That's how I got mine.

 

[MtnMan307]

Oh yeah, I know the soundstage of the K7 will probably never happen with a closed headphone. The think sound on1 was on mass drop recently but not enough $$ for now.

 

[Darien]

Oh yeah, I know the soundstage of the K7 will probably never happen with a closed headphone. The think sound on1 was on mass drop recently but not enough $$ for now.

check out the takstar pro 80/hyperx cloud - they have the same soundstage as the open takstar 2050s, and sound really good - can easily compete with cans under 300$ which is the most i would pay for closed cans. takstar lives in some magical fairy land where they can do whatever the hell they want, make closed cans with same sound stage as the open 2050s :O its probably my favorite set of headphones as far as closed go also i find the hyperxcloud version very comfortable! 

 

[FaezFarhan]

I've just placed an order of the Aune T1se while waiting for the arrival of my recently ordered K7XX. Purchased both without auditioning. Hopefully I'll fall in love with both!

Right now I'm coming from the ATH-M50, IM50 (tho I like the IM70 more), and the SE215 LTD. Been a while since I had a proper audiophile headphone. The last was the Beyer DT880 a few years back. Paired that with the TinyTube DAC. I kinda miss the airy vocals of that headphone but now I'm excited to get use to how the K7XX sounds like..

 

[steve12345]

Oppo HA-2 vs. Schiit Modi 2 + Vali 2 for K7XX?

 
 
Narrowed down my DAC/amp choices for the K7XX to those above. Wish I knew how to run a poll on this.
 
Will pull trigger today.
 
Any last minute selection advice from a pure sound quality perspective for the K7XX, ignoring the portability difference?  
 
 

 

[MtnMan307]

Vali 2 kicks ass for the K7xx. I don't have a dac yet but doing a modi 2 uber when cash permits it.