This is going to be a review of the Project Ember. I'll start with a general product introduction and then the review itself. The photography takes a variations on a theme approach with versions of an image edited in different fashions. I hope you like it as well as the review.
Now for a product introduction. The idea of the amp, designed by Jeremy and Frans from Garage1217 is not to compete with anything, but to explore what's possible and that is exactly what they did. The amplifier can use most breeds of 6 volt and 12 volt tubes, features gain switches, and output resistance jumpers all of which have a substantial effect on sound. The amp is designed to have "split personalities" as Jeremy likes to say and she does with the ability to sound like a warm and "tubey" sounding amplifier with warmer sounding tubes such as the Telefunken and high output resistance settings and an equal ability to sound almost like a solid state amplifier with a colder tube and low output resistance settings and everything in between. It's predecessor, the Project Sunrise II has been compared by reviewers to the Schiit Lyr and the Ember is a notable improvement over the Sunrise II in that it has more power (enough to power the AKG K1000 and Hifiman HE-6 due to its max of 1.8 watts into 64 ohms), more detail, more customization options, and automatic biasing and voltage selection. In fact, due to the excellent distribution of power through all impedance ranges, the Ember can power 600 ohm headphones (380 mw) and extremely low impedance headphones with equal ease.
As far as how she sounds, it's not as much of a question of what she sounds like, it's what she can sound like. Imagine a clean signal coming from your dac. The amplifier provides multiple filters so to speak to the sound - the first being the gain level (I'd advise using low), the second being the tube, and the third being the output resistance. I'll talk about how the tubes alter the sound first. The circuitry of the amplifier is designed so that the opamp stage produces the smallest amount of distortion so that the only thing that distorts the sound is the tube. The effect of this is that tube rolling makes worlds of difference as far as how the amp sounds (I have a fair amount of them to say the least) . To give a brief description, here are some of the possibilities. With a Sylvania Baldwin 12au7 in, the amp sounds fairly exact and precise -- almost like my o2 except for a bit of roundness to the bass (which stays very snappy) and the smallest amount of lushness to the mids. The presentation is fairly neutral with a moderate sized soundstage. Put a Phillips 5814 in however, and it's an entirely different story - the soundstage becomes wider, the mids develop a more lush sound while also being very airy, a slight treble roll off comes and the bass develops a more round quality. Then try an RCA 12AU7. The first thing you're hit with are mids as they are very forward and vocals are the highlight of the presentation with a sound that's somewhat thick but extraordinarily fast. The sound is very clean, with somewhat bright treble and a slight bass roll off. Then try an Amperex Bugle Boy 6DJ8 and you're greeted with a wonderfully natural albeit a bit dark presentation with excellent soundstage and imagine. The possibilities are absolutely endless as tubes make a world of difference.
Tubes, however, are only one option that you have to adjust sound. The output resistance settings also have a large effect as the second layer of the filter over the tube. Keep in mind that the descriptions that follow are based on change to the tube's sound signature - tube rolling will still make a huge difference no matter the output resistance setting. Want a more airy sound with a more round bass presence that is a bit more stereotypical tubey? The high output resistance setting is for you. Want something that's closer to the solid state degree of precision without the airy lushness? The low setting would work best. Want something in between? There's a setting for that too. I tend to use the middle setting for most of my headphones.
As far as synergy issues go, I'd recommend pairing the Ember with as transparent of a dac as possible so that the tube creates the only audible distortion in the chain as tube rolling makes more of a difference that way. For headphone synergy, pretty much anything works due to the wide array of sounds that the amplifier can produce. There is most certainly a tube and output resistance setting that will make any headphone sing. For example, my Grados prefer something warmer like a Phillips or Mullard tube. The AKG headphones that I have are good with pretty much anything because as I touched on in the K702 review, they pair well with cleaner amplifiers and tubes. With my Fostex and Denon headphones, I generally prefer something mid forward like the RCA or a Bugle Boy because in the case of the Fostex, the mids are its best feature and I like to showcase them and in the case of the Denons, I find the mids slightly recessed so a mid forward tube evens things out.
For the price of $350, I could not recommend this amplifier more due to its flexibility, warranty, quality and overall sound quality.
And for a bonus pic that breaks the theme
Thanks for reading and happy listening! Please post any questions/impressions that you have and suggestions for the review/photography etc. If you'd like to see more of my reviews and content you can find it on my blog here http://musicandlistening.wordpress.com/