[Sodacose]

​

 
 
First off, I should disclose that I have these headphones on loan from my job.  These are a demo pair, but it’s really not a product category that my company focuses on (we are not in the consumer electronics or hi-fi markets).  I just happen to be an audio enthusiast and occasionally get access to audio enthusiast products through work.
 
So when Blue started marketing headphones with built-in amplifiers, I was a little skeptical. To make a long story short, I think they accomplished what they set out to do (add a useful feature without a crazy price premium for it). Their built-in amps are not the end-all, be-all answer to headphone amplification, but they certainly improve upon the typical headphone output of a mobile device. 
 
The Ellas use a planar magnetic driver (50 ohms) in a sealed enclosure. The amp charges via USB (12 hours claimed life) and has both an Active and Active+ setting (the latter boosting the bass). I was most interested in the performance of the built-in amplifier and so I’m just writing up my thoughts on using the Ellas from a portable device as: passive headphones, Active mode headphones, and passive headphones with a ‘standalone’ amp (see pic). My Moto Z Play is the source used for all comparisons. I’m not going into great detail on the headphones themselves just because I have fewer frames of reference when it comes to headphones in the price bracket ($699) and especially sealed planars.
 
I’ll break it down by thoughts on specific tracks (track names are YT links but I used high bitrate files for listening).  I’m using passive mode as the ‘control’ so descriptions of Active and standalone amp are in reference to it.
 

Zero 7 - In the Waiting Line

Active Mode
Cymbals sound excellent in Active mode. Sustain and decay is very realistic and sweet sounding without some of the grain I get in passive mode through a mobile device. Vocals on this track are more intimate and present than in passive mode. Harmonies especially are more coherent. The synth line is huge and enveloping. In some ways though I feel as though there may be too much bass and it encroaches on the mids. Note this is Active mode, not Active+ (which just adds more weight to the low frequencies). The bass doesn’t sound bloated, there’s just a whole lot of it.
 
Standalone Amp
Vocals maintain their intimate quality with a ‘big’ amp here. They also seem just a little more ‘flesh and blood’ than with the built-in amp in the Ellas. The acoustic guitar gives a lot more detail in its reverberation and string movement. The overall atmosphere with some of the leslie type stereo effects and rhodes keyboard is more pronounced and adds to the feel of the track. Bass is less with my standalone amp than with the built-in amp. 
 

Lemon Jelly - The Staunton Lick

Active Mode
This track opens with an old sample. A decent setup will let you hear some of the recording space and imperfections. I get a much better picture of this in Active mode than in passive mode. When the track switched from the sample to the guitar loop, it’s readily apparent due to the slight timbre change in the guitar. The drums have more impact in Active than in passive, though I feel like the snare is a little recessed. Kick drum sounds very good. 
 
Standalone Amp
Certain little things really jump out on this one. The creaking of the chair in the opening sample, the sound of the recording space, and the crackle throughout is much more apparent. In addition, the snare is still not super snappy (probably the recording, not the amps), but you can hear the whole shell of the drum. In all, there is more detail. 
 

Ray Lamontagne - You Can Bring Me Flowers

 
Active Mode
Really good feel of pace on this track. Again, the cymbals really stand out with a natural tone. I still feel the Active imparts just a bit too much focus on the midbass. The wind instruments are a little tough to separate but it’s obvious that there are both woodwinds and brass playing. Active mode gives this track a much more relaxed feel than passive, which sounds just a bit lifeless by comparison (not surprising, considering the source is a regular phone).
 
Standalone Amp
Somehow the high hat just didn’t catch my attention in Active mode, but now it’s front and center as the track opens. Similarly, the ride cymbal at about 1:10 grabs your attention and the drums at 2:00 or 3:00. At 3:40 that flute comes in out of nowhere. Something about it is just a little more captivating here with the big amp.
 

Yosi Horikawa - Starlings

Active Mode
This track opens with what sounds like steel bearings dropping onto wood. As they drop in increasing numbers, it takes a lot for the system to be able to keep it all intelligible. In passive mode, it quickly turns into white noise. In Active mode, the detail is preserved and offers some hidden gems that otherwise get missed. It sounds like each impact is followed by a reversed playback of itself, adding some interest to the track.  The throbbing synth (or whatever it is) is mind numbing in Active mode. Passive mode does not compare in terms of how big Horikawa paints the picture here.
 
Standalone Amp
The bearings intro has more acoustic information with the standalone amp, but what is more surprising is the sound of each one continuing to bounce as others fall. This is a tiny detail and difficult to resolve as the track progresses.  That the heapdhones are able to do it at all is a point in their favor, I think.  As in other tracks, the bass boost from Active mode is gone, but the throbbing synth sound has a little more texture even if it has a little less weight. Some of the other instruments take on a little more character late in the track as well.
 

Conclusion

I think the Ellas are a very nice pair of headphones with a decent built-in amp. The amp in Active mode adds a lot in comparison to using the headphones in passive mode from a mobile source. Bass is certainly more present and the rest of the frequency range also feels more relaxed and organic. On the other hand, there is more detail that can be wrung out of the drivers with a quality separate amp. Put another way, the headphones themselves scale pretty well with amplification. I don’t think there’s anything wrong with that and I certainly don't consider it a fair apples-to-apples shootout comparison.  The two chassis for the standalone amp probably weigh close to 40lbs together; the fact that the built-in amp gets close in performance is pretty commendable. Not that we're strangers of diminishing returns around these parts.
 
Because the headphones do not fold and are on the bulky side, I can’t see tons of people using them when traveling and so the value of the built-in amplifier is a little tricky. In passive mode the headphones are ok, but who uses $699 headphones without an amp?  So you’ve got a nice pair of headphones that are certainly worthy of a standalone amp, but you’re paying a little extra for a built-in amp that may or may not get used (again, these probably aren't headphones to throw in your carry-on for a flight). That said, the Active mode built-in amp is certainly better than no amp at all. The headphones also get very, very good with a standalone amp. If you have an application for that middle-ground built-in amp, say you find yourself listening primarily from a mobile device or want something for the studio or your desk at work, it’s darn convenient to have one less cord/device to worry about. 
 
 
Note on the pictured standalone amp: this is a single-ended transformer-coupled 6L6 with a choke-loaded 12BH7A driver (right chassis). The power supply (left chassis) uses a tube series regulator to regulate the high voltage. It is adjustable so that 6L6/EL34/6V6/KT88 tube types can all be used and the B+ dialed in appropriately.