Sorry, I’m a bit late to the party, but did you end up buying that non-booting d8b?
I don’t have any MDR/HDRs or a Mastertrack, but made one working d8b out of two non-booting ones after I bought them for dirt-cheap. And the usual suspects on here really were an invaluable source of tips and help along the way.
It’s definitely a challenge (I took the boards apart close to 10 times, checking for other ribbon connections I had possibly missed, getting deeper and deeper into the board every single time… total PITA!!!), but it worked out for me in the end. Or I should say… after ongoing digital sync problems, I finally realized that the card cage in my main d8b, didn’t like to have all the slots filled. With only 3 I/O cards in it instead of 4, it works just fine.
BUT, you said a few things about devices with digital connections and wanting to use those, but at the same time kinda pointed out that you don’t care about the different types of digital connections and formats, etc. I think that even if you would get all of those devices to work just fine by themselves, to really make full use of them together (meaning, connected digitally), you have to read up on how digital synchronization works - otherwise, you’ll just run into all kinds of digital audio glitch and noise burst problems.
The most basic rule never to forget about digital connections is that “THERE CAN ONLY BE ONE (digital clock master… nothing to do with Highlander)”. Everything else that is interconnected digitally at the same time, needs to be set to be a digital clock “slave”.
So, the idea to connect the digital output of all these various devices you mentioned to the d8b or to one of those digital recorders, is a bad one, IMO. Any device that doesn’t receive a digital input, but only a digital output ALWAYS wants to act as clock master. And multiple clock masters will result in glitches, crackled, pops, clicks and bursts. Too many cooks, basically.
Essentially, you have to first decide which device will be the clock master and provide word clock to all other digitally connected devices (word clock = synchronization info about all those 44,100 samples per second that you’re sending over each digital audio cables… or 48,000, depending on the sample rate. They need to be synched. If they don’t they sorta collide, and make a noise).
If that d8b you want to buy only has the stock clock card, and not the Apogee clock card, then the decision has already been made. The d8b MUST then be the clock master. This means that anything that you want to digitally connect to an input on the d8b, first must be connected via a digital output on the d8b to the digital input on said device, to send the “word clock information” to that device and allow it to sync to it- and that external device must be configured to synchronize it’s word clock (the digital frequency it runs on) to the incoming word clock from the d8b. Any device that is configured like this (a “slave” to the word clock signal coming out from the d8b), can then be connected to any fitting digital input on the d8b without a problem.
It gets a bit more complicated, once you’re using devices that require word clock sync via dedicated BNC connectors, rather than just via the digital audio connection. Then you’re dealing with having to Terminate the connections in some cases, and not in other cases (depends on if the devices have built-in termination that is switchable or not, etc.).
Anyway, I hope all of this doesn’t confuse more than it helps. But it might give a glimpse how complicated the inter-connection can get when you have multiple digital devices in the chain (not just the d8b and a single digital recorder) that are all being connected with digital audio connections.
But heck, if you can’t get the d8b to work as a mixer, you can always get a ProBox from munkustrap here on this forum. This will turn the d8b into a 24-channel DAW controller. That’s what I did with my second d8b, where the CPU still won’t boot. (In fact, I have two ProBoxes, so I can run them both as controllers, while the “mixer” d8b still passes signals through in that mode).
Sorry… lots of confusing text. But maybe it helps a little. Understanding digital audio isn’t that bad, really. It just takes a moment to wrap your head around, but then that knowledge is really useful to troubleshoot all kinds of odd audio issues on digital devices