Okay, so I couldn't wait the full 14 days for the paint to dry haha, I waited 11 then decided I'd really like to enjoy the amp this weekend. I was very careful about securing the power transformer to the chassis. Like I said I would do before, I held the screw and turned the nut instead of vice versa. Worked out perfectly; no paint chipping or tearing.
The build was super relaxing and it was a lot of fun planning and carefully routing each wire, though the way I did it made me run out of wire about 4/5 of the way through the build. I used 19AWG Kimber copper wire that I had on hand for the headphone jack because of this.
I was originally going to use alligator clips for the output caps for easy rolling, but thanks to Paul (PB), I improved upon this idea. He made it clear that alligator clips aren't the most reliable and could potentially pop off. So, I went with spade connectors—they're both secure and not difficult to detach. Though, I did have to test fit the connectors and use pliers to make the tension just perfect. The cable for the output caps is from an old, standard composite video cable that would otherwise never be used. Glad I could call that benchwarmer into the game after sitting in a dark A/V box for well over a decade. Its flexibility is great for this scenario. Also, I zip-tied these cables to the chassis, so the solder joints won't get stressed when I cap roll.
What else can I say? Everything went smoothly....I took my time and tried my best.
It passed all the resistance and voltage checks, and whoa....
Been listening for a couple hours now....the bass detail and imaging is really getting me excited! Keep in mind, I did A/B compare the Crack and C2a at Bottleheadquarters back in January of 2020. Doing so again brings back a lot of what I remember. The lower registers are more detailed and separated from the mix, and the whole sonic picture has a power and spaciousness about it, but with a sense of ease as well. Similar to what going from a 40WPC to a 120WPC amp did for my inefficient bookshelf speakers.
Tangled Up in Blue by Bob Dylan [HD track] sounds ever more atmospheric—his voice is a little more spaced forward compared to the more closed-in sound of the Crack, and the space around him can be sensed better as well. Same with Nocturn by Kate Bush [vinyl rip], the wind and swooshing sounds seem outside of my headphones. The Sextetts have really good spaciousness, but I haven't heard it anywhere near this level with other amps. And here we go....what it's all about for me, and a good reason why I wanted this amp....to get me closer to this performance....Nirvana Unplugged in NY (DTS track, DVD concert). Pat's guitar is very easy to follow compared to how it gets a bit blurred with Kurt's guitar on the Crack. And Kurt's voice in Come As You Are....man, he sounds so much better here than in the studio version....and the C2a delivers with startling clarity and serious, serious verve.... Kurt's voice grabs my soul as if it were a tangible thing. It has a grip on it and the experience is exhilarating. The C2a delivers all the rasp and all the emotion in his voice, and he's placed very precisely in the soundscape, again with the atmosphere all around him expanded beyond what I'm used to hearing and all the other instruments easy to follow in their precise locations. I'm so happy I discovered OTL amps, they really do drive my 600-ohm AKG K240 Sextetts better than any other amp type I've tried—and the Crackatwoa is a seriously deluxe OTL design. I also tried the C2a as a preamp in my downstairs speaker system with a 6.35mm-to-RCAs cable. The sound projects more into the room, dynamics are greatly improved, the tone overall is very full sounding, and voices especially sound much more full-bodied and lifelike compared to going through just my A/V receiver.
Interestingly, my AudioQuest DragonFly v1.0 is completely silent through the C2a, whereas with every other amp, the USB noise comes through at louder volumes. At max volume with no music playing, the C2a has a bottomless pit of a noise floor. So, it's a USB noise killer along with being a beautiful-sounding amplifier. I'm so, so pleased with this. Also, the Audio Note pot I have is sooooo smooth to use. People often describe weighty pots like butter, but this is more like warm Laffy Taffy haha—the resistance is truly luxurious feeling. Okay, I'm going to go keep listening till the sun rises.
Thank you so much, Dan, Eileen, Paul, and Paul, for everything. I'm really, really happy right now.