The new A12t incorporates as the first model aside from the flagships the TIA technology, but contrary to the 18t and Fourté it also implements 64’s new Linear Impedance Design (LID).
The LID is, as the name spoils, able to make the A12t unaffected by output impedance, which enables it to have the same sound with any gear. This linear impedance behaviour makes the A12t the perfect monitor for audiophiles, audio engineers and musicians alike. Professional gear usually has higher output impedance than audiophile gear.
Vitaliy, 64 Audio’s CTO, was kind enough to give me a little insight on this new technology introduced with the A12t and Tia Trió. The LID tech is a specially designed circuit that selectively loads certain areas of the earphone. It sits parallel „on top“ of the crossover network and flattens out the problem areas of the impedance curve of an IEM. That made it possible for the IEM to have the same frequency response (+/- 0.5dB) no matter what it is connected to.
Apart from impressive technology used, the A12t looks gorgeous throughout. It’s my very first CIEM to have a clear shell. To be honest, I saw this exact design on 64’s Facebook page and it looked so good that I had to steal it. Designing a new custom IEM is the toughest part in my opinion. So I’m happy I found something I like that someone else took already 😉 Clear shells, aluminium face plates and white print on them. They look even better in real. I hope my pictures somehow can do them justice, but I don’t feel they do. The clear shells let me peek at the open TIA balanced armature drivers, though it is hard to get a good look. Since the nozzle is of round shape the acrylic breaks the light in such an unpleasant way that the picture of it gets bent… still cool to look at them though.
The A12t has a smooth midrange with sweet vocals, throws a punch that could knock out Mike Tyson with one touch and gives you all the TIA treble extension you need. It is rich, organic and has very high resolution and a sound stage to dive into. It matches very well with a wide array of DAPs, DAC/Amps and amplifiers. On top of that you will also get two APEX modules to change the signature to your taste.
One of the things that wowed me from first listen was the incredible sub-bass. It has an authority like I’ve not heard from any in ear around. It reaches deep and renders at a very high rate. The coolest though, is that it gets completely hidden when it is not needed. Most monitors I know have sub-bass bleeding into mid-bass, which is fine. The 64 approach though makes it seem that it is completely separated from the rest of the bass response. It makes me re-listen to so many songs to experience that bass, it lets me rediscover them in a completely new way.
If you own a pair of A/U12t’s, listen to Kraftwerk’s ‘The Robots’ or Siriusmo’s ‘Plastic Hips’ to see what I’m talking about… Those still give me goose-bumps.
By the way: Vitaliy also told me that implementing LID into the A18t and Tia Fourté is something they’re considering 😉