canyoncruz

I would be interested. I you willing to negotiate some? Thanks CC

Ask Mike when the Cobalt sounded better than their Gen XX

That should be sufficient for music. If you want to stream 4K video, you might want to look at the high end models. For music, you might also want to look at the Pentium quad core models. As far as keeping the same case, I would suggest the PPA be placed above the cooling fan. and wired down the side to the internal USB 2 connector. The lid is plastic so you could 3D print a taller one which would house the PPA. Intel has the mechanical models available for the case. If you need help, I could CAD up a lid and you could shop it out for fabrication.

You best bet would be to polish with a 6 - 8 Deg angle. What this does is push the back reflection away from the LED by use of its lens and also increase the angle of back reflection within the fiber such that is no longer contained by TIR (total Internal Reflection) and escapes the fiber - but you still have the band width problem as far as low jitter is concerned

Toslink has a few problems. The cables" the plastic ones have a very high index of refraction and are not AR (Antireflection) coated and hence a large amount of light entering and leaving the fiber will be reflected, Upward of 10%. With Fused Silica (Quartz) it is about 4%. Though Toslink uses LEDs which are broadband, the back relection sets up an optical cavity causing the LED to favor some discrete wave length with in the their broad line witdh. This can cause modulation of the source and modulation withing the fiber due to Etalon effects. Next the band width of the fiber does not really support the crazy low jitter (ps) in SPDIF transmission. Glass toslink uses bundles wgich is slightly better in bandwidth but now you have multiple signals which can modulate (interefometric effects) at the detector. The core size of these fibers still do not support large bandwidths with the toslink sources. With the so-called AT&T systems, they use single mode optical fiber though some where multimode. Single mode is best. But lasers used in them are sensitive to back reflection. There is a type of laser, the DFB (Distributed Feed Back) that have internal grating to stabilize and reduce reflection effects but they are expensive. With the laser signle mode fiber systems back reflection to the laser are the biggest contributor to jittie. Single mode optical fiber can easily transmit 100 GHz as is the knew state of the are these days. A 2.5 Ghz laser and detector (transmitter and receiver) are commodity devises these days. For audio, the fiber runs are extremely short so back reflections withing the fiber are high. There are solutions: For the fiber purchase one with an "APC" polish (And angled conical polish) with AR coating. for 1.3 um. Here's a 5 meter patch cable with APC polished FC type connectors for $10. AR coating will probably add another $20 to $40. FIS Simplex 3mm SM FC/APC-FC/APC Ultra Fiber 5 Mtr - Fiber Instrument Sales For the Transmitter and Receiver: I would go with the 1.25 GHz 1300 nm (1.3um) FB (Fabry Perot) Laser because this one gives you the choice of PECL or TTL and DC or AC coupling. http://appointech.com/TRX/Tx-Rx/SM%201.25G%20Transmitter-Receiver%20_May%2014_.pdf These are similar to what Theta Digital offered but at a way lower Bandwitdh.

I am glad I found this series. I have been looking into the latest NUC. I have a Theta Gen VIII series three which has every type of SPDIF input, including the Single mode laser (or really ELED). The direction I am going to with extract the audio from the HDMI and convert it to SPDIF. ST Micro amongst others have an IC for this. This will allow transmission up to 192 kHz which the Theta can resolve. Next I plan on taking this signal and reclock with an WM8805 or DIV9001 then into a TTL to PECL converter and finally into a DFB laser module with about 1GHz bandwidth and <.1 nS rise time. I had worked with theta, developed their ST Laser interface. Originally we used and demonstrated a DFB laser at CES. The difference was night an day. The cost for the device was $2k. Impractical for even High End audio. So we went to an ELED which performed well. BTW, DFB lasers have come down in price dramatically. Another issue is the short fiber length and with TOSLIK, high index of refraction for the finer and back reflection at the interfaced and also inside the fiber. During this time I manufactured fiber optic cables for Straightwire and Audiquest. These use a higher bandwidth 50 um graded index fiber with angle polishes. If done right the optical interface can outperform all others. Unfortunately, these high performance lasers (these days up to 40 GHz) are in wavelengths of either 1300 or 1550 nm. Not compatible with TOSLINK's 628 nm. I am photonics packaging engineer by trade and device cooling is one of the main hurdles. Lasers have a high thermal flux than u-processors. on top of this they have to typically be kept to a tenth of a degree of the set point over say the military temperature range (-40 to 85 C). A lot different than making sure an IC doesn't exceed 125 C. So to remove the fan I will go with a thermal electric cooler (TEC). With this instead of the processor being some delta above ambient, I can have it at 10 to 20 C below. A simple supply is needed if there is no set temperature. the Heat sinks will work harder, but that's where you want it to happen. This will still use reflex condensers (heat pipes) Modifications to the NC will be, drill holes for the laser interface and PSU, additions of a heat sink to top or bottom or sides, and separate liner supplies for the HIDM to SPDIF conversion board, the NUC itself and the thermal management system. At first glance it appears all this can fit into the NUC case.