Ok everyone wants to know how it works so ok.... This is NOT a combination single IC USB DAC like many of the others which uses inferior SigmaDelta DAC output conversion. NO the Cosecant like the Cosine uses a Multibit DAC IC with a single Shinko Tantulum resistor as a Passive I/V conversion. Because only a resistor can be a linear device over the entire audio band.
The Cosecant is powered by a external power module using Linear Technologies regulators and Hexfred Rectifiers. The DC-IN is feed into Power Central which has 5 separate regulators for the different parts of the Cosecant and uses 22 Black Gate (7 BGNX HiQ, 7 BGN and 6 Standard) capacitors for the best sonics available.
The USB Controller is told by the Computer that the system is Active which wakes up the Tube output. When the Computer is off or a sleep the USB Controller tells Power Central to turn off the High Voltage section and the tube's filament.
The Tube (6GM8/ECC86) output is parallel feed and has an output impedance that is 500 ohms. Both the Audio Choke and Output step down transformers are made by MagneQuest.
In designing this product I looked at allot of the available USB Audio DAC chips. These really did not excite me much at all. Most of them where one bit Sigma-Delta units. So I stuck with the Transcendental DAC we use in the Cosine. There was no need for the Caffeine options since jitter was so low. This DAC is basically a multibit 16 unit with passive I/V and does not have any analog or digital filtering. As well it does not adhere to up or oversampling. The tube output does filter the output in it's own way and the transformer coupled output assures both isolation and good drive capabilities. So we use a USB receiver for this DAC to our Transcendental DAC technologies to the 6GM8/ECC86 tube with parallel feed transformer output.
If you have more questions please give me a call or an email.
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