I'm a proud owner of the Fireface 800 and I'm starting to build up my first professional recording-studio - but now I need more output-channels. Does anybody know, if it's possible (and a good solution) to extend the Fireface 800 with e.g. a Focusrite Scarlett OctoPre Dynamic (I used it once and I really liked the quality)? And if so, could I use its inputs too? For now I want to stay with the Fireface as my master-interface.

(I don't want explicitly ask for better recommendations on extending the Fireface which would be off-topic, but if you have any, feel free to let me know)

  • 1
    Owenm's answer put a doubt in my mind... The title says you need more outputs but the octoPre is a preamp, so will add inputs only. I considered the title to have a typo for my answer, is that the case?
    – Tom
    Aug 25, 2022 at 5:35
  • @Tom you're right. I thought "easy, has adat in and adat out, so should work both" - hell no, just input does work... so I still will have to search for another way... :( - sorry, need to remove the "accept" Aug 25, 2022 at 19:36
  • That's normal, I got confused by the text and didn't consider there was an ambiguity there as it was a preamp, I hope you did not buy unneeded gear because of me...
    – Tom
    Aug 25, 2022 at 20:05
  • @Tom haha sry I'm a noob ... nope, wanted the Scarlett anyways.. :D so I use it now as preamp via adat to Fireface :) but need to check if sounds better with Scarlett inbetween or without and if there's a difference Aug 25, 2022 at 20:08
  • 1
    The only limitation of adat will be sampling at 48k, otherwise it should be completely equivalent as the signal is already digital, hence does not degrade with repetition :)
    – Tom
    Aug 25, 2022 at 20:22

3 Answers 3


I don’t know why it is repeatedly asserted here that you cannot send Adat out to an octopre. There are multiple versions of the board that have both Adat and line ins and outs, though possibly not capable of 96khz

update from OP: you can use ins and outs simultaneously by activating the ADAT -> Line button.

  • so you mean, it is possible to send both, ins and outs? I don't need 96kHz, I think (since my mac always struggles a bit with this) I stay with 44.1kHz anyway. and can we use ins and outs at the same time? Feb 1, 2023 at 10:45
  • @MatthiasBurger yes it appears to be the case, sorry I potentially mislead, I have used several octopres of all different ages and never seen the model with the adat in addition. Yes it appears you can use them simultaneously with the inputs in ‘Adat to line’ mode. I’ll edit my answer above to make sure there’s reference of the version of the octopre with both ins and outs.
    – OwenM
    Feb 1, 2023 at 13:47
  • @Jim so I will give it another try... that'd be really cool - I didn't buy the ADA8200 yet :D... Feb 1, 2023 at 15:05
  • @Jim thanks for your answer, this actually made me to take a look again. it works! I just missed to press that little button "ADAT -> Line" ... ohhh so cool, you don't know how happy I am.. - you mind to update your answer to make it as a "real answer"? so I can take this as the accepted one :) Feb 1, 2023 at 16:51

The Fireface 800 has two ADAT port, each of them can be used to add 8 audio channels in to your interface. The OctoPre Dynamic will interface perfectly with that as it also has ADAT out connection.


The standard Octopre or similar things by Audient or even Behringer are a great way to add more inputs. And have only ADAT outs, meaning they can't accept digital audio inputs from your master interface, they are just used to add more A/D inputs to your system.

However some models of the Octopre also accept ADAT inputs which can be routed to the units analog line outputs on the rear panel via the 'ADAT > line' button. These can be used simultaneously to the units ADAT outputs > recording interface. Such versions of the octopre (eg. the Claret+ Octopre) can add 8 additional inputs and 8 additional outputs to an interface equipped with ADAT ins and outs.

Apart from the higher end Octopre's with this feature the only other device I know of (though there may well be more) is the RME ADI-8 MkIII which is also a 2 way expansion to the RME fireface, but should work with any other ADAT equipped device.

One ADAT cable will carry 8 channels of audio at lower sample rates (44.1Khz, 48Khz), each cable only carries 4 channels of audio at higher sample rates, hence they tend to get provided in pairs, and you will need to use both for 8 channels at higher sample rates in either direction.

Each ADI-8 or suitably equipped Octopre would add 8 inputs and 8 outputs via two ADAT cables (one in, one out) ADAT at lower sample rates, and 8 inputs and outputs via dual ADAT cables (two in, two out) at higher sample rates. Unfortunately you can't use both ADAT's at lower sample rates to get 16 channels of audio in a given direction because at that point you are limited by the physical number of analog connectors these two particular devices have.

You also have the option of getting an extra couple of outputs from the SPDIF I/O's, on top of the analog I/O's and ADAT. If an interface has both SPDIF and AES/EBU then often they are tied, so the same signal goes to both.


As pointed out by one of the other answers, things have moved on, in terms of features of the gear available compared to my experience when I first wrote this answer. I wouldn't be surprised if there are more standalone ADAT D/A A/D converters around now other than the RME unit and the higher end Octopre's, it's not before time too!

  • somehow the max sample rate that works currently is 48k .. when I go higher I don't get a signal. With the OctoPre I get more inputs, but seems like outputs don't work. ADI-8 MkIII blows budget (yeah it's rme... great and expensive) and the only option I could find is Behringer PowerPlay 16... and that's Behringer.. :D I will need to check for other solutions - or could I just add another Fireface 800 via adat for more outputs? Would still be in budget... Aug 25, 2022 at 19:52
  • 1
    No, the RME Adat outputs will not do anything plugged into the Octopre output, that’s just jamming random data in some socket where it shouldn’t go! The octopre is an A/D converter, for outputs you need a D/A converter. The octopre has 2 Adat outputs, you will need to use both at the same time and set it up correctly to use sample rates over 48k. The Behringer you mention isn’t Adat, it’s Ethernet, designed to interface their mixing desks, that wouldn’t help! You could buy another fireface, but you can stack them so if you had two you may as well run them together and ignore the Adat outs!
    – OwenM
    Aug 27, 2022 at 13:38
  • 1
    The behringer ADA8200 ultragain has long been considered one of the best options for this. I know it’s behringer, but this is one unit that’s generally accepted, do a gearslutz search for more info. It has ADAT ins and outs, and is less than £200. It’s at a price where its worth a look, its a bit of an oddity, as as you can see most solutions will be getting nearer the pro end of the market and be very expensive. Don’t think of this as a product recommendation, but it really is the only thing I’ve ever came across that will work for this job at this price point!
    – OwenM
    Aug 27, 2022 at 13:56
  • 1
    Yeah, I understood the intention, but there’s no real benefit to having a second fireface 800 connected as a relatively dumb ADAT slave, to get 8 extra I/o, when you can just daisy chain the two interfaces and use the analog I/o of both to achieve the same thing. Plus the octopre pre on the first fireface to get 8 MORE inputs. Using the second as an ADAT converter will work, but may require you to plug into the second, configure it in the software, unplug and plug into the first, configure that etc. whenever you want to set-up. I’m sure you can do some kind of state-save on the second though…
    – OwenM
    Aug 29, 2022 at 21:18
  • 1
    If you just stacked the two interfaces you would still get 16 I/o +8 for the octopre, except both fireface would be configurable from the software. You could even get a second octopre and get TONNES of inputs. What I mean is if you have two fireface 800’s then you would get the same extra I/o wether you used it as an ADAT slave or as a generic second interface, and the latter allows much more options for easy config.. No, tbh I think you’ll be fine on a 48k max setup… I’ve rarely felt the need to use a higher rate, maybe once or twice in my ‘career’!
    – OwenM
    Aug 29, 2022 at 21:19

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.