It's a DIY design, and a new one at that, so there aren't any commercial units available.
That's mostly correct, the stacker II is not a commercial product. The DIY part is a big confusing since there's no official schematic for the design, technically it isn't finished yet although I think the builder of these two amps has an inside line on that.
a little late to the party but I am well pleased that you both ( E & J ) have identified why I once mad the brash statement that I was listening to the best amp I had ever heard. My opinions have not yet changed and it has been a few years. enjoy ..dB
I have owned some great amps (Dynahi, Moth 2a3 and Eddie Current HD2) as well have listened pretty extensively to many/most high end (expensive amps) and the Stacker is right there sonically with them. It embodies the best attributes of tube and solid state sound and frankly sounds like neither designs stereo typical sound.
So far my headphone listening has been limited to the Audio Technica ad2000, brief listen with a PS-1 and the senn 650s. The amp sounds like it was made for the Audio Technica AD2ks as I have not heard them sound any better (maybe the balancing act). Sense of space, detail and texture were all world class. There was plenty of PRat with dynamics done really well.
It is going to be a treat to get more ears around this amp as it is a game changer. It further goes on to prove (at least to me) that the DIY community can design and implement amps that are as good as and in most cases better than commercial offerings. Both Earl and my build were on the upper end from a cost perspective but I am certain that similar sonic results could be had with a more economical build as well.
Thanks to Cavalli Audio for a stellar design and thanks to Donald for taking this build on. I'm not sure many here realize the work that goes into building a DIY design amp for someone and I owe him a debt of gratitude for taking this on.
After a few weeks I'll do a more in depth review/impressions but I've kind of spoiled it as I already love this amp. Any one coming to CanJam will be able to hear it in my rig at the event.
Yeah, maybe when the final designs are ready for public release, my funds for a new amp will be ready! New amp, new headphones, new cables last few months, jeesh. Now gotta start saving again after this review.