Thanks for the feedback on the DR-100 coax input. I do get some great recordings via the coax on that unit.
The ety's already do the hard work, compensating for human ear linearities, etc. When my mics are set up binaural and I'm recording it's like I'm listening with my ears, no electronics involved. But I'm not a real audio engineer. My thing is psychology and sleep research. Or it was until I retired. So my electronics background is focused on designing specialized EEG amplifiers for research along with hard-core data acquisition. Used to run a metrology lab somewhere back in history, designed and built the data aquisition system for testing and validation of the Titan IV rocket launchpad components, then did medical device engineering for a day job. Audio electronics is for me a passion for sound itself. My ears are my primary sensors. And music is an essential part of my life.
I like to build mics that can 'hear' what my ears hear, i.e., provide a signal that replicates what I hear normally. Of course we know microphones cannot quite match our ears. But they can come close. In my experience most people do not use their ears properly. Detail tends to become filtered by the brain automatically. It's the brain filtering that needs to be tweeked more than anything else. Just my two cents. Consumer electronics is dependent upon brain filtering to create a sound that seems like it's real but it's not. It's called compression. Trained ears are repulsed by it.
Last I heard AudioEngine had some W3's remaining on amazon. I purchased another set recently. The case can be opened if you're careful and longer USB cables soldered in for attaching the unit to a recorder with 3M sticky tape. The boards themselves are very well designed and the circuit represents the simplest implementation of the chips possible. The transmitter requires little current at 5vdc. The receiver even less. Some 5v power bricks require a resistor to be added in parallel to boost the current draw above the point where the power brick senses that there's actually a load. Otherwise the power brick won't run. Just a few milliamps is necessary. The analog signal in and out is in the range of 2v, not sure if that P/P or RMS. The W3 response is suprisingly linear.
The W3 circuit boards can easily be remounted inside other gear and not have to be an addon. It is incredibly unfortunate that the W3 has been made obsolete. The TI chipsets were not a success on the market because they cost more than cheap bluetooth chips. The market in this case is stupid. Paying just a little more for uncompressed sound is too much for the market to bear. Bluetooth had to be compressed and tweaked just to provide the minimum latency necessary for watching a DVD movie or streaming video online. The TI chipset in the W3 is so close to being a wired connection that in most cases it is transparent. In my home I use Ety ER4PT's with a FiiO amp and a W3 receiver in my pocket to listen to everything, pc's, music server, etc. while I work or putter about. Up to three receivers can lock onto one transmitter.
Now I sound like I'm a bloody shill. Well, maybe I am when it comes to innovative semiconducters that should have become mainstream.
Are we off topic yet?