d8b Forum

I have a D8b with 4 Adat cards and 3 AIO 8 cards. The converters are good, but are now over 20 years old. I am interested in using the Apollo x8p or x16 because the converters sound much better. Is this possible if I use D25 cables and the AIO 8 cards to send audio in and out of the D8b? Can I bypass the converters in the D8b?

The 'AIO' in the name of those cards stands for "Analog Input-Output", so, if you're using those, you're not bypassing the converters in the d8b to interface between the Apollo and the desk, but you're converting Digital-to-Analog-to-Digital every time you'd send signal through D25 cables between the two.

You'd have to stay in the digital domain to bypass the converters. But the D25 I/O on those Apollos are always analog, not digital.

You're probably confusing that with either 8 channels of (digital) AES/EBU over D25 connectors, or with the Tascam TDIF digital Format (I don't think new audio hardware uses the TDIF format anymore). Those cables "look" the same, but the signal going over them is different, and the ports on both, the Apollo and the AIO cards are NOT for AES/EBU (digital) or TDIF over D25 - they're just analog (using converters on the way in and out).

So, the short answer is, the equipment combination you mentioned, does NOT do what you're asking.

You could get DIO-8 cards for the d8b instead of the AIO cards, combined with an audio interface that has a couple of ADAT ports (e.g. the RME Digiface USB). Then you'd send 8-channels of digital audio (without using converters) between the two devices per optical ADAT cable (up to 32 channels on that RME interface I mentioned).

But even with a setup like this, there's not really a point to going through the d8b while recording - there's nothing in the d8b, that would add to the quality of the signal, IMO. Not only the converters on the Apollo are better, but also the plug-ins that are available for the Apollo. The Apollo UAD plug-ins are getting pretty close to the real hardware pieces they're emulating. The d8b's plug-ins are from the early days of when plug-ins even became a thing - so you can imagine the improvements and innovation that happened in that area in the last 20 years, too.
Also, Apollo interfaces do a great job at latency compensation when using plug-ins in their Console app on their way in.

Yet another reason not to have the d8b in the chain, is because it's limited to sample rates up to 48 kHz. On the Apollo, you can go higher if you want (up to 192 kHz, I think)... but if you have the d8b digitally tied in, you're stuck with 44.1/48kHz on the Apollo as well. (The ADAT ports on modern audio equipment can do S/MUX for higher sample rates, at the cost of a lower channel count - the d8b can't do that, either).

Long story short, even with all digital cards in the d8b, I don't think you'll really have a benefit out of routing signals between the Apollo and the d8b. It makes everything more complicated, while even having to make other compromises (routing on the d8b becomes a PITA as well, IMO).

I'd record straight to the DAW via the Apollo, and MAYBE route the signals through the d8b during playback, so I can easily adjust the levels via the faders... but for that, you could as well stay in the box, and get a fader-box instead... or the ProBox for the d8b for that matter. In fact, that's what I do with my (older) Apollo 8.

Anyway, good luck with your setup! I hope you find something that works for you!

Btw... I just re-read your post, and realized that I skipped over you also owning 4 ADAT cards for the d8b already (I guess you meant that you could swap out cards because you already have them, since the d8b can't hold 7 I/O cards at a time).

So, you'd already have that half of the setup... then I realized that my Apollo does actually have an ADAT port, so I wondered if the Apollo 16x maybe has two of them and looked it up... but it doesn't. It has (digital) MADI ports instead (lots more channels over a single cable), but there's no MADI option for the d8b, so there's not really a solution to transfer 8 or 16 channels at a time between the d8b and the Apollo 16x in the digital real, since there are no compatible interfaces for it (i.e. no MADI for the d8b).

The Apollo 8x apparently DOES have two ADAT ports, but you can only run up to 8 channels total of ADAT I/O at the same time. The second ADAT port is for S/MUX... if you'd run at 88.2 or 96kHz, each ADAT port can only transfer 4 channels at a time by "S/MUX-ing" the signal. To transfer 8 channels at those sample rates, you'll have to use both ADAT ports on the Apollo 8x. (If you go up to 192kHz, each ADAT cable can only transfer two channels of audio).

But everything else I said still applies. Maybe some others here have a good idea why it would be a good idea to route your signals through the d8b, if you're using an Apollo X interface... but IMO, it just gets complicated for no tangible benefit.