Black Lion Audio Premium mod with new apollo 8

Ok, I think I can offer some opinions here, as I think I'm the only one here who's both a professional designer, and I've designed a converter system..

There are a few different ways to skin a clock..

Top of the line is an OCXO (Oven compensated crystal oscillator) which self regulates it's own temperature in a little heated box to keep the crystal at a constant temperature and therefor frequency. This is what professional test and measurement equipment use, but the OCXO devices are typically hundreds of dollars just for the part. Layout and supporting components are critical. Most of the time in professional devices, these serve as the master clock for the whole system. Each IC that needs a different clock frequency or type will have some device either divide or multiply the master clock to the correct frequency. Dividing a frequency also divides the jitter, so it's always better. Multiplying a frequency directly will multiply the jitter, so generally a PLL is used to create a new frequency because the loop/feedback can maintain a lower jitter than multiplication alone can (but it's still higher than the master clock). I'm not aware that any audio equipment uses these. Cost is usually 100-1000$+

Next up is the TCXO (Temperature compensated crystal oscillator) which self regulates the output frequency by pushing or pulling the oscillator bias based on some type of temperature reading. It's not quite as good as the OCXO, but it's orders of magnitude cheaper, and still orders of magnitude better than a plain crystal. I know a few higher end audio devices use these. Cost: 15-100$

XO is the third, which is generally a crystal and some kind of driver circuit in a small box. Some have internal feedback to steady the frequency, but they are still pretty temperature sensitive and will move around a lot with the smallest changes in temp. Most audio devices use some variant of these. Cost: 1-50$

A plain crystal is the last. It's generally a piece of quartz between a couple wires inside of a metal can. You add a stimulus signal and the crystal itself will vibrate at a resonant frequency. The manufacturer will cut the quartz in certain ways to trim it's frequency or change the way it resonates so that you get overtones or other attributes. It's cheap and reliable for low performance applications. Only the cheapest audio devices use these, but some use them in conjunction with PLLs or something to create a low cost clock with decent performance. Cost: 0.25-20$


You also have hybrids like DPLLs which will be small PLL systems in a small package that act like a TCXO but usually offer better control and programmable abilities as well as multiple output frequencies, etc.


So these are just the options for clock sources..


So as tonycamphd mentioned..  It could be as cheap as 25-50$ to put a serious clock source in place, but then you add the overhead costs (labor, stocking, placement, higher layer count PCBs, etc) and you're looking more like 50-150$ for a good clock system for a big interface design on a very wide ranging product, when you include all the subsystem and supporting parts.

But then, even with those types of costs, I have to ask, why is BLA asking for 1400$ for their mods?  You're looking at a few hours work and generously assume 200$ worth of parts all-in.. Assume a 50% profit margin and you're still sub 400$..