by Y-my-R » Sat Sep 19, 2020 9:16 pm
Looks like you already have some ideas going where you’d like to take this, so I don’t want to roll this up from the beginning… a couple of notes, though:
1. To “control” Logic from the D8B, the ProBox you said you have is the ticket. This works the same way, as if you had a Mackie Control Universal with two Extenders. In regular operation, the D8B does not “control” Logic, but you can route audio between the D8B and Logic, of course… that’s what this thread was all about so far. It IS possible to use the D8B as a controller AND as a mixer at the same time. The “official” way is to just use the D8B’s built-in HUI emulation (see manual), but this will only allow you to control 8 tracks at a time, and the Master Fader won’t do anything.
The “unofficial” version, is to connect the D8B to a DB25 serial A/B switch, and have switch A go to the D8B rack unit, and switch B go to the ProBox. This way, you can boot up the desk as a mixer with the switch in position A, then make all the mixer settings you want, and switch over to the ProBox on B, to control Logic.
I have it set up that way, but switching back and forth frequently resets the faders, and the Meters kinda get a mixed bag of information from mixer operation and from the ProBox when doing it this way. So, it’s not really an official way to use it, but it generally works.
2. The problem with buying a USB interface with 3 ADAT ports (apart from there not being a lot of choices) is latency. Latency is a delay between the moment a sound happens, and until it comes out of your speakers. The D8B doesn’t introduce any noticeable latency, but depending on the speed of your computer and how low you can set your audio buffer (the lower, the less latency), a USB audio interface WILL introduce such a delay/latency. Professional musicians usually notice a delay (and get distracted by it), when the latency is higher than 8-10 milliseconds. That’s right around the limit of what a USB device can deliver - but only if you have a very fast computer. So… it better be an i7 processor with at least 16GB of ram… faster/more is always better. Then you might be able to drop the latency down more, to get less of a delay.
The solution to the delay, is to use a Thunderbolt Audio interface. Your results will differ, depending on the computer and the interface/drivers, but the best latency I was able to get personally, out of a PreSonus Quantum interface, was under 1 ms. This is not noticeable to anybody. Unfortunately, the Quantum only has 2 ADAT ports on it… but you can run multiple units cascaded, to get more ADAT ports, if that’s what you need.
Personally, I combined a Quantum and a Universal Audio Apollo 8, to get 3 ADAT pairs, but I do NOT recommend that. The UA latency is much worse than what the Quantum can deliver, and the slower device’s latency will be applied to all devices you connect at the same time. The Apollo is still fast enough so you shouldn’t be able to notice the latency, though. I did also see some deviations when it comes to the placement of the audio on the tracks between the two units, even when synced to the same word clock and SMPTE, so this might result in phasing. Because of that, I NEVER use them at the same time to record anything (but I don’t use the D8B in my setup in a traditional way, anyway).
3. MIDI: It doesn’t matter if it’s via a separate device, or built into the audio interface. The results are the same. I would NOT recommend a Unitor 8 or AMT 8 at this point (even though I’m still using a Unitor 8). There are no official drivers for the latest Mac OS versions for these devices, and you have to install a (free) 3rd party control panel software to get it to work, that is likely to stop functioning with some upcoming macOS update. Besides, in my case, the Unitor 8 never gets recognized after boot up, and I always have to swap USB ports with another device, to instantiate it.
Besides, there’s no more AMT support in macOS - not the device, but the method Emagic used at the time, to have MIDI transmissions not be slowed down by the serial protocol (they sent stuff to the Unitor/AMT a bit early and buffered it there, and then sent it out to all the ports at the right time via MIDI time-stamping). The MOTU interfaces use a similar methodology (buffering and time-stamping), though, that is still supported in current macOS versions. In short, MOTU MIDI interfaces will give you better MIDI timing than a Unitor 8 or AMT (…or any other multi-port interface, for that matter).
I’d strongly recommend a MOTU MIDI interface for that reason.
…oh, and if you want to go on the cheap… I’m not sure what “MIDI cable” you were looking at, but something like an M-Audio Uno does pass SysEx without problems, so this would work fine. If you go even cheaper than that, then I’m not sure if such manufacturers test their devices for less common stuff like SysEx or RPN/NRPN messages, etc.
4. A word clock generator like a Big Ben is always a good idea, but not a requirement. If your setup is simple (e.g. audio interface and D8b), then you can just connect word clock between the two and have one be the word clock master, and one be the word clock slave. Once you add more devices that need to be connected digitally, a Master Clock like a Big Ben is recommendable, if you don’t want to deal with the inherit complications of daisy-chaining devices that need to be synced via word-clock. I daisy-chained everything for a long time, but eventually caved and bought a used Lucid Genx192 for $200 (and traded a stagebox I had lying around for $100 of that)… so, if you can get a Master Clock cheap, great! But it isn’t needed to get everything going to start out.
5. An old Mac Pro will not allow you to run the latest version of Logic, since you can’t upgrade it to the latest operating system. Logic added a whole bunch of really useful features in updates over the last few years - you’ll get none of these features if you use an old Mac Pro. I’d recommend against that at this point.
Having said that, you also need to be careful about newer Mac offerings. The company I work for bought me a new Mac mini, for example, and if you use it with high monitor/screen resolutions, this sucks up so much of the computer’s performance and makes it run hot (which results in CPU throttling), that you can’t achieve the low latencies via Thunderbolt, that I was talking about before. In order to get the latency down to around 6 ms, so I can play an electronic drum kit through a virtual drum-instrument in real-time, without noticeable delay, I have to reduce my screen resolution to 1080p. Trying to run the monitors at 4k, would force me to increase the latency up WAY to high to avoid pops and clicks in the audio, to a point where I can’t play the drums anymore, since the sound comes out so much later than when I hit the drum(s).
In short - unless you want to invest in an eGPU (an external graphics card enclosure with a higher performing graphics card it it), you can forget about a Mac mini as your DAW computer - at least if you want to use higher screen resolutions than 1080p.
…sorry, if you’re relatively new to the audio world, then some of the above is probably a bit hard to follow.
My recommendation for now, if you mainly want to CONTROL Logic, would be to use the ProBox with your D8B, and use it as a MIDI controller (i.e. like a Mackie Control Universal with 2 Extenders). When you got that going, that’s when I’d look into what all the other stuff I’m mentioning above means, and how to solve all the inherit potential trouble that you may not yet be anticipating.
Anyway… sorry that I spam this forum yet again with another “novel” like this. I guess that’s just how my mind works. I hope it’s still useful in some way.