First off, there is a video that talks about what's inside their boxes. Obviously they have come out with newer generations of their technology and they are now using more surface mount resistors and capacitors and are a little more elegant to look at than their earlier generation.
Secondly, they do not use Zobel networks, per se. They have a patent on their network design. Plus, they are creating LCR networks centered around musical note frequencies and their harmonics. Obviously, the more expensive cables have more networks inside, which is what makes them better and more expensive.
These LCR networks are NOT wired in series like an EQ or "tone control". They are wired in parallel.
Basically what they do is they measure cables for a variety of different things. They look at phase angles to make sure everything is in proper phase. What they do is they take the frequencies associated with musical notes and their relative harmonics.
They look at rise time, decay time and what they found out is that cables don't have a linear response curve for the entire bandwidth so they create these networks that are wired in parallel and they center them around certain musical note frequencies. so they can create a cable that is more linear in the rise and decay time across the bandwidth of audio.
I would recommend watching their video.
https://www.youtube.com/watch?v=yK3WY2bNaqoThey show an example of one of their boxes in one of their higher end models. But they are moving into using surface mount components.
They also use cable wires that are based on three different gauge stands of wire and each gauge is put into bundles of a specific number of wires per bundle. Because they have to be careful about phase, they have to wire them on tubular winders and they twist the wires in a centric manner with something like 10 turns per inch. A regular twisted wire that's sold really cheap use one strand size and they just bunch them up and put on high speed winders and they might twist the wire once every foot. Then there is the purity of the wires, MIT does use the highest purity copper wire. I think it's something like 99.99999% pure or something along those lines. VERY expensive wire compared to cheap copper cables. They also use a specific type of dielectric to insulate them.
I've been using their products for about 30+ years and love them. They are very neutral and they don't have distortions which can cause ear fatigue.
I don't know what's going on with their site as it appears that it's down right now. They might be changing their website which what I think is going on, but they do have a loaner program so you can try them out for a 30 day period with no obligation to purchase. You only have to pay for shipping the demo cables back to them.
The reason for the expense is they use premium materials, they do a lot of hand matching with high resolution impedance testers to ensure they are consistent, and they are made in the US and they are simply expensive to mfg. and they are a small company that sell in small quantities, so they are a niche type product.
Even if you can't afford their more expensive cables, their entry level cables are quite good. They have boxes you can connect standard 12gauge copper wire to if you have in wall cables for your speakers. They are relatively inexpensive.
