Wavelength Cosecant v3 USB digital/analog converter Manufacturer's Comment
Editor: I want to thank both Art Dudley and John Atkinson for all their hard work. There is a lot more done by both of these men than what you see in these pages, and they should be thanked for that.
I had sent the Cosecant to John after he used it at the 2008 Rocky Mountain Audio Fest to give several demonstrations of resolution of audio files. I had put the unit in balanced mode, and that, I think, is why Art had the hum problems he had. Simply switching the internal DIP switches will result in the ground wire he used being no longer necessary; this is how all units are shipped from the factory.
I was surprised by the Cosecant's inversion of phase, as all tests had indicated it did not. The good news is that the Numerator's MCU controller (the single dotted socketed part in the exposed picture of the Cosecant on the Numerator module) can be replaced with a new one that will initialize the Wolfson DAC chip to the correct phase. Any current owner can request this; it is a very simple operation, or have your local dealer help you out. All new Cosecants will be fitted with the revised MCU.
People seem to find themselves listening to more music with computer audio. It is probably the one thing most people say, and the early comment about Art leaving the Cosecant on and playing for eight hours seems to indicate that he agrees.
I am glad that John found the jitter of the asynchronous USB to be the best he had ever tested. As Art noted, it took almost a year to develop. While I was working on that, I was also working on the required low-jitter oscillators to ensure that the jitter going into the USB audio receiver (TAS1020B) was as low as possible. I would like to thank a few people who helped with the discrete power supplies and transformers, and whom I often bounce ideas around with: Pat DiGiacomo from Analog Research; Clarke Green and Mike LaFevre of MagneQuest; and Charlie Hansen of Ayre Acoustics. Thanks, guys; I could not have done it without you. Also thanks to Kelly, Nutmeg, and Riley for all their support.
Many people who don't know who I am or what I have done in the past have asked why I use tubes. I explain that I prefer their character of sound and the simplicity of the circuit. A product line is something that has to be the same throughout. Sure, I could have done this all in solid-state, but then it would not sound the way it should to fit the Wavelength Audio name. I appreciate Art's kind words in his "Conclusions"; he must have heard what I was after.Gordon Rankin, Chief Scientist, Wavelength Audio