I received this amp around two days ago after getting it built from a really quality guy (the "Headamp Builder" on etsy, if anyone was curious). I basically wanted a TotL amp that could power speakers and headphones and had a good deal of versatility. For the most part, I stuck with Victor's build, but I did sub the vcap cutf's in with some Duelund tinned copper to provide some additional warmth, and I also had my builder tinker a bit with the resistor network that goes to the headphone out after hearing that series resistors tend to degrade the sound.
A preliminary warning: this amp has only been burnt in for around 35 hours or so, and it supposedly takes quite a bit more time to burn-in. I've been switching between Tung-Sol and Fivre 12BH7a drivers, with Linlai Elite power tubes. So far, I think this amp is pretty remarkable, albeit with a couple important drawbacks. Firstly, in terms of clarity, layering, sheer sense of space, separation, and microdynamic nuance, it is at least a league better than anything that I have heard before (yes, that includes the ECP 3F and TU-8800). It handles music with an ease and effortlessness I don't think I've ever heard before. In short, it provides a clearer window "into" the music than any other amp I've heard, and I've never once heard it sound remotely congested in a busy passage. Though the stage isn't massive, images are extremely well-localized. Bass, though not particularly slamming, has a supremely nuanced sense of pitch, texture, and control. And the sense of decay, delineation and air around treble notes is at times awe-inspiring: the cymbals in "dreams" seem to run on forever, and one can actually hear with more tangibility the precise changes in volume of these instruments as the strike of the cymbal decays slowly into nothingness. All this is, to say the least, fairly impressive.
That being said, I do have some quibbles with the way that it represents instrument textures in the mid-range. It has a sort of high-end "sheen" to it which tends to lead to a homogenization of mid-range timbres. For what it's worth, this is something I've heard on every amp with Lundahl transformers (including the 3F and 8800), though to a perhaps lesser extent than what is present in the 8900. In short, there's a kind of almost artificial top-end sparkle that crowds out the crunch and presence of mid-range elements like voices and strings while also tending to make their timbres all sound alike. It also is just a tad harsh-sounding, akin to the way that a Focal sounds, albeit without the "metallic" timbre or "edge" to the transients. In fact, the transient edges are, if anything, not adequately well-represented: the amp lacks a certain sense of grunt and bite that even the much cheaper ZMF Pendant OG had. Since this amp also tends to lack any sort of notable warmth or wetness in the mid-range, this can occasionally lead to a sound that is simultaneously sterile and unengaging. For the most part, I don't find myself tapping my foot with this amp despite it having what I think are the best microdynamics I've ever heard - there just isn't enough sense of "realism" and palpability to the instruments or attack in the transients, two things which I think are essential to musical engagement.
For what it's worth, many of these problems have been getting less noticeable as the amp has burnt in, and I also think that they are at least partially due to the pairing with the Soekris 2541, especially since this amp is supposedly quite sensitive to sources. In fact, when I used my loaner r2r Cayin dongle, many of these issues, particularly the timbral ones, entirely disappeared, though the amp did take a hit technically. What I surmise from this is that to a good extent, this amp tends to take on the timbre of the sources that it's used with. In this way, this amp reminds me a good deal of the Focal Utopia - it's extremely revealing and a tad on the thin side, so pairing with the correct components is going to be absolutely essential to getting the most out of it, since its sheer transparency will tend to make it very sensitive to the gear that it is paired with.
I am going to burn-in this amp a good deal more, potentially swap caps, and give it a go with an Abbas 2.3se, since I really do think it would benefit from an aggressive, full-bodied dac (the soekris 2541, which is simultaneously thin, relaxed, and lacking in plankton, seems like exactly the -wrong- kind of pairing for this amp). I will let you all know what I think when I do so, but for now, this amp is not quite the slam dunk which I thought it would be.
