Hey, a similar setup to Pietcrux! We really like the Pentaconn connection, as it’s easier to connect to and for designers to fit on an amp, sized good for portable and home use, and thicker so as to be less prone to breaking than a 2.5 mm balanced plug. Both of our new HD 660 S and IE 800 S come with a 4.4 mm Pentaconn terminated cable.
We don’t have an exact date for you, except “soon.” We have been producing them in our Ireland factories and working on getting them shipped in bulk to more countries and authorized dealers! Thank YOU for your interest!
We can’t speak to Tyll’s process specifically, but many in-depth reviewers like to get to know a headphone and take notes (and sometimes measurements) and hone in on what they want to say. On average, they like to spend a month or two with the headphone.
Commenting specifically on our driver designs and the “secret sauce” that goes into making them is not something we will go into detail. However, there are two things we would like to share:
1.) There is definitely a trickle-down benefit of all our research and development in our higher end headphones that we have put into the HD 660 S.
2.) We would recommend focusing exclusively on any singular component, and expect to predict what the full sonic outcome will be. As you have found for yourself, the HD 660 S has quite a different character to it in contrast to the HD 700 or HD 650, despite being designed to have the same frequency curve as the HD 650.
We are glad you have enjoyed the HD 660 S, and in return we enjoyed reading your impressions a couple pages back! We obsess over the design process, and thus are excited to hear people’s first impressions of our new products as much as people get exited to hear new products for themselves!