I think I received the Sonett 2 after Toads was done with it, so I'll share some impressions. Please let me know if you have questions.
In the meantime, I'll say that it's the best headphone amp I've spent time with. It's not in the slightest bit tubey sounding—the S2 is fast, extended, dynamic and highly resolving, the way I like it. And it retains the lit-from-within quality of good tube circuits as well as the beguiling lucidity of transformer-coupled single-ended triode amps. It's also powerful sounding, driving the Senn HD800 and HD650 with unremitting control. I hope to borrow the LCD-2 this week to try with it as well.
Part of my mission with the Sonett 2 was to figure out a way to tame the HD800—to make listening to it pleasant and relaxing rather than a cringe-fest. I'm happy to say it's come a long way. First, I replaced the stock cable with a Cardas cable with 4-pin balanced connector. Balanced drive on the S2 added bass, richness, a slightly wider soundstage and, of course, gain. (I cannot swear how much of the difference was due to the cable itself and how much to XLR drive, but the new cable helped a lot.) Replacing the JJ rectifier tube with a Mullard was another step in that direction—more richness, color and bass. Swapping out interconnects produced very audible differences as well, and the amp highlighted the distinctions between Cardas, Van den Hul, Analysis Plus and Wireworld. The S2 also allowed me hear the sound of different tubes in the buffer section of the DAC I was using, the MHDT Havana. Maybe the most unexpected gain came from lifting the amp off the shelf and letting it sit on 3 Vibrapods—the headstage got much bigger and more of the HD800s wiry tendencies receded. Now, with the latest version of Audirvana Plus providing an almost electron-microscope view of detail, the HD800 floats a huge stage with almost no hardness or brightness apparent. Far less fatigue. It's the sonic equivalent of being at a planetarium for one of those weed-scented rock shows—everything floats around the head. I'm psyched.
Experienced Head-Fiers sometimes refer to the HD650's ability to "scale," and now I know what they mean. They sound insane with the Sonett 2, passing much more detail and ambience than I though the headphone was capable of. Really silly good. If not for the HD800, this combo would make me happy.
I appreciated the impedance and gain switches on the amp, but I didn't use them much. I preferred the impedance on low and gain on normal. Setting it on high softened the sound and added a layer of mist and bloom, which I didn't care for.
I've never heard the original Sonett and listened to the Stratus briefly at a meet, so I can't make meaningful comparisons to those amps. I can say that my Bottlehead Crack, a great little amp, isn't even in the same parking lot as the Sonett 2, which is better in every imaginable way. Same goes for the Matrix M-Stage, but more so. I heard the Bryston amp recently with my HD800 and frankly found it a little boring. While hosting the Sonett 2, I was happy to drop in on a fellow Head-Fier here in Brooklyn and listen to his Decware CSP2+ and EC Zana Deux through my HD800. I was unfamiliar with his (very expensive) DAC and cabling, so take these impressions with a chunk of salt. I did notice that the CSP2+ sounded more traditionally tubey than the Sonett 2, with a more prominent upper bass, more forgiving treble and less apparent power through the Senns. I can understand why the Decware amp is such a popular pairing with the Senn, but I preferred the bigger, clearer sound of the Sonett 2. The Zana sounded powerful, detailed and transparent, much like the S2, but to my ears added a bit of high-frequency etch that I didn't think flattered the already treble-prone Senn. It was also hot as a furnace.
I'm pretty thrilled with Sonett 2. I can't hear any character to it's sound that could be described as a flavor. It' strikes me as pure, transparent, and neutral, but not in the least boring or polite. It's colorful and rich. It has plenty of power and control with the phones I've tried it with. I can, as they say, hear things I've never heard before. It doesn't make me want to do something else after listening for 15 minutes. It makes the HD800 into the most revealing transducer I've heard—and, with the right attention to ancillaries, also makes it fun, something I wasn't sure was possible. It's not too big. I really like the way it looks, and that it's blue. And I can't think of another amp under $2K I'd rather listen to (though admittedly I haven't heard the EC Super 7).
Thank you, Donald North, for the opportunity to live with your new amplifier for a while. It's terrific.
