It's 2017: good amp for AKG K240 DF's?

[RamblinE]

Hey yall. See bottom of post for TLDR. I was super excited to win a pair of these off of eBay but I ran into a problem. For years I have been using a Headroom Micro Amp as my main headphone amp. It delivers for my K701 and doubles as a little preamp. It does struggle to power the K240 DF though, with some songs kicking the amp into distortion. I sure wish specs had been more readily available on the Headroom but at the time of purchase I may not have even known what a 600-ohm headphone was. 
 
Specs are hard to come by for the DF too but from a PDF of Tyll's measurements they are: 
Volts RMS required to reach 90dB SPL: 0.792 Vrms
Impedance @ 1kHz: 613 Ohms
Power Needed for 90d BSPL 1.02 mW
Broadband Isolation in dB (100Hz to 10kHz): -7 dBr
 
So when I'm looking at amps around or under ~$350 how should I interpret those specs? Is this headphone even so much yesterday's news that it'll be hard to find modern amp recommendations? 
 
In my living room is where I've been using the DF in the system shared by my partner and I. The padded resistor output on our Yamaha receiver can drive them, and the eBay dirtball Indeed G2 I bought years ago also does the job, with more detail and better transient response but at the expense of pot noise and a general air of unreliability. 
 
I've been looking at the:
 
Little Bear P8 OTL
Schiit Vali 2 Hybrid
Little Dot Mk II OTL
Schiit Asgard 2 SS
Darkvoice 336SE OTL
Schiit Valhalla 2 OTL
 
I know the OTL's are better optimized for high-impedance cans, of which I do have several, and according to the specs they deliever more power. However the hybrid and solid state amps can also deliever more power to lower impedance cans as well, and I do use my K701 semi-regularly and my K550 for streaming TV (the joys of apartment living). When I'm looking at the Vali and the Asgard though, they deliever 140mW RMS and 190mW RMS respectively at 600-ohm. Tyll's measurements of the DF list 1.02mW required for 90db spl. Am I interpreting it right that even the Vali would be overkill? Or do I NEED to look at the OTL's for their much higher power delievery even though I'm looking for a compromise for high and low impedance? 
 
TLDR; Amp shopping for inefficient 600 ohm K240 DF. Am I reading specs right that even the cheap Vali 2 can drive it or do I need an OTL headphone amp to unlock their full potential? 

 

[PurpleAngel]

The Indeed G2 may not have been full tweeked and balanced to bring out it's best, from the factory.
A DT830 multi-meter and a small philips headphone screwdriver are need to adjust each of the channels 
Here is a forum for Indeed G2 support.
http://rockgrotto.proboards.com/board/8/headphone-amplifier-forum
 
If your willing to budget for the Darkvoice 336SE, go for it.
https://www.massdrop.com/buy/dark-voice-366se
I Darkvoice 336SE works well for me.

 

[RamblinE]

  The Indeed G2 may not have been full tweeked and balanced to bring out it's best, from the factory.
A DT830 multi-meter and a small philips headphone screwdriver are need to adjust each of the channels 
Here is a forum for Indeed G2 support.
http://rockgrotto.proboards.com/board/8/headphone-amplifier-forum
 
If your willing to budget for the Darkvoice 336SE, go for it.
https://www.massdrop.com/buy/dark-voice-366se
I Darkvoice 336SE works well for me.

I have gone through the tweeks for the G2. If I could ask one thing about the Dark Voice, how does it do with the K7XX and other lower impedance headphones? 

 

[PurpleAngel]

  I have gone through the tweeks for the G2. If I could ask one thing about the Dark Voice, how does it do with the K7XX and other lower impedance headphones? 

 
The AKG K700 series headphones are listed as 62-Ohm, but are slightly more power demanding then my 250-Ohm Beyer headphones.
Later today I'll see if i can find my AKG K7XX headphones and test them with the Darkvoice.
 
I'll see what other low impedance headphone i might have around and test them with the Darkvoice.

 

[KyungMin]

I run these three amps..
 
Solid State: Audio-GD Sparrow DAC/AMP
Tube: Schiit Valhalla 2 and Musical Paradise MP301 MK2 using the FiiO E17K/K5 dock as a DAC
 
I just picked up my K240DF of some guy on offerup for $60.. He found them at goodwill and knows nothing about headphones.
 
The musical paradise has ALOT more power than the Schiit does but is a bit more picky with tubes...
To get about the same output my schiit is at 2/3 and the Musical Paradise is just a tad over 1/3.
These cans require more power hungry than my Beyerdynamic DT990 600-OHM
Something really weird is my headphones for some reason play mono in both the right and left channels.
Took them apart and they have never been modded... Weird..
 
Also I do plan on getting a Darkvoice eventually.

 

[RamblinE]

  I run these three amps..
 
Solid State: Audio-GD Sparrow DAC/AMP
Tube: Schiit Valhalla 2 and Musical Paradise MP301 MK2 using the FiiO E17K/K5 dock as a DAC
 
I just picked up my K240DF of some guy on offerup for $60.. He found them at goodwill and knows nothing about headphones.
 
The musical paradise has ALOT more power than the Schiit does but is a bit more picky with tubes...
To get about the same output my schiit is at 2/3 and the Musical Paradise is just a tad over 1/3.
These cans require more power hungry than my Beyerdynamic DT990 600-OHM
Something really weird is my headphones for some reason play mono in both the right and left channels.
Took them apart and they have never been modded... Weird..
 
Also I do plan on getting a Darkvoice eventually.

I never thought about the Musical Paradise actually. I have tried similar products though like the Sound Quest SQ-84 (shop that owns Sound Quest is local), but I was priced out of that pretty quickly. The MP-301 looks like a great compromise. 6.5W is just enough power for my desktop speakers (AR Holo Image M.5). With the Valhalla I'd still need something like the T-amp I'm currently running. 
 
I can't ask specifically about the DFs since yours are running mono, they very well could have been modified ages ago for monitoring use. With your other cans do you like the Valhalla more or the MP-301? 

 

[KyungMin]

Musical paradise has more power.. I ended up getting a fiio e17k/k5 combo which I use as a dac. I have yet to use the mp-301 as a speaker amp.. but is an added plus.. the Valhalla 2 is dead quiet and has low gain setting so I can run these with my lower impedance cans.. but the musical paradise looks a lot better when the lights are off.. both are built pretty solid.. the schist does have a better warranty I believe.. I can't say really which one I like more because I have close to 40 pairs of headphones and run certain ones on certain amps.. but the musical paradise runs the df better. Less gain and is louder... from memory the schist needs to be turned to 3 o'clock to be as loud as the movie-301 at the 12-1 o'clock position

 

[kvik]

I use Zigis Rock’n Glass with my K240DF, and it’s an excellent match (to my ears). I used K701 for at short while with RnG, and thought that pairing worked well also. Same goes for HD650. RnG+Beyer T70 wasn’t to my liking, T5p worked ok with one particular tube.