Options for getting more inputs in on DM4800

[551Studios]

Howdy.

As the title suggests, I'm looking for more ways to get more than 24 tracks of simultaneous recording on my DM4800. I've tried to do as much research as can but admittedly I'm a bit of a dolt on some of the technical aspects of some of these things so there's a few "grey spots" for me in terms of "will this work or not" (I just know how to plug stuff in and press record for the most part...").

Anyhow, my board came with the IF-AN/DM and IF-AE/DM cards... I also just recently became aware of the expansion feature via the IF-AD/DM card and possibly the built in ADAT port on the back of the mixer.

It seems for the most part, recording at 44.1 or 48 these expansions will be pretty cut and dry (which is nice), but I'm interested in starting to record at 96 for future projects, and it appears with some of these mediums your available track inputs are cut in half due to the limitations/higher resolution of each device. Ostenstibly as well, it seems that the board is limited to recording at 96, despite some of the components being capable of 192... lol... did I miss anything here?

That being said, I wanted to try and have the best understanding of each method to try and figure out what's the best way to achieve what I'm looking for.

I understand that with the IF-AN/DM, the stuff that's coming into the board thru the DB25 connector is an analog signal, for which I figured I could neatly get that sound through a TASCAM 8p Dyna 8 Mixer (which has the DB25 port on the back of it as well as 2 ADAT ports). That would give me 8 extra channels (albeit via analog) of inputs through the DB25, in your opinion what are the drawbacks/limitations of this route compared to the other methods? It appears according to Cmaffia that this would still be 96 capable.

The IF-AE/DM has the same DB25 port on the back of it, but honestly I could not find much info on it at all, what I could find didn't seem to suggest it worked the same as the IF-AN/DM, am I wrong? Is this a way to get 8 extra channels as well? I read in this Gearspace thread that it can take up to 4 channels of 96 (which I would assume mean 8 channels of 44.1/48); or rather the the AES/EBU method generally can...
https://gearspace.com/board/audio-s...on-question-zone/955189-aes-ebu-question.html

Lastly, we come to the ADAT method via the IF-AD/DM card and the built in port... I was able to dig up more on this method, parts seem straight forward about it, some I'm still a little cloudy on. If sticking with 44.1/48, I can get 8 channels of audio into the board via the built-in ADAT port, or 4 @ 96 according to Cmaffia in a different post. In that same post, Cmaffia elaborates that the expansion card seems useless for recording any higher than 44.1/48, and further (I'm a little confused by this statement) that "In addition, when you check SLOT information screen for the ADAT expansion card, it will tell you 44.1/48kHz are only supported when the console is configured for 88.1 or 96kHz."... That seems sort of backwards if it means anything at all...? Why would the resolution of the board have to be increased in order for that card to allow recording at 44.1/48? Thread:
https://www.tascamforums.com/threads/does-the-if-ad-dm-card-do-96k.4982/

Expanding on the ADAT options, it appears the TASCAM 8P Dyna 8 Mixer is capable of sending through 8 channels @ 96 via S/MUX (2 ADAT cables from what I can gather, 1 for 1-4 and 1 for 5-8) - however, this seems a bit useless as the only way to get 96 into the board via ADAT is the built-in port, and there's only one of those...

So that being said, it appears the only "easy" or direct way of getting 8 extra channels of 96 is via the ID-AN/DM card...? Up to the point of typing this all up I was under the belief that the board could pass through more than 32 channels of audio into my DAW, and it appears from what I've gathered that it's futile to attempt any more channels than that simultaneously via the IF-FW/DM MkII... this is true, correct? Not that I really need more than 32 desperately, I just thought it would've been neat to maximize the board's net-input capabilities for either 44.1/48 or 96.

Out of curiosity, my Mac Pro does have multiple firewire ports... w/ 2 DM4800's w/ FW cards (I'm assuming cascading off of each other..?) and connected to the back of my Mac Pro, is that the only way to achieve more than 32 channels of recording? Not entirely sure if my machine would handle it, I would imagine it could possibly, it's a 2.93 12 Core, 128 GB Ram, SSD drives... Anyhow, just wanted to get the expert's take on options here. Thanks in advance

 

[mixerizer]

AWESOME POST! I learned a lot, thank you.

I think you are on to the best solution.

I assume you are using 32ch of Firewire at 96k as you mention.

The Dyna 8P in an expansion slot is a really good choice for adding 8 analog inputs. If you are using the DM’s analog inputs 1-24 as well, that’s 32 more channels.

So with two slots used, you have 32ch of 96k analog and 32 of 96k FireWire if so.

While TDIF, AES-EBU and ADAT protocols can all technically carry streams at 96k and 48/44.1 as u observe, for the DM only the AES card and internal TDIF and ADAT can operate at 8 channels / 96k and the internal ADAT provides 4 channels. DM ADAT cards do not have that high speed SMUX mode (not sure about TDIF cards). I don’t know if the AES card works at 96k w 4 or 8 channels, but I suspect it’s 8. Using ADAT cards at 96k is therefore limited, as you describe. Not only do you only get 4 channels, you can’t use clock sync as the super helpful image from the manual Cmaffia posted in the linked post makes clear.

So if you can snag 2 AES-EBU cards, and use the internal ADAT, you will have 12-20 more digital channels, giving you 12-20 96k external digital inputs and 32 96k FireWire inputs. If you wanted to give up the 8 analog inputs from the 8p you could use another AES card for a total of 16-24 external digital inputs, 24 analog inputs and 32 FireWire inputs, all Mixable and or routable via the various banks of output. If you can find a way to use the TDIF ports as well that means 40-48 digital inputs.

Alternately, you may want to consider using another interface as an aggregate device (Mac terminology), which will allow you to route audio from that interface to your DAW along w all or some of those 32 FireWire channels. I’m not sure if you would want two DMs w FireWire on one Mac but possibly!

 

[Arjan P]

it appears from what I've gathered that it's futile to attempt any more channels than that simultaneously via the IF-FW/DM MkII... this is true, correct?

There is nothing to attempt here, the card has a limit of 32 channels in and out (any sample rate, 44.1, 48, 88.2, 96k) - and can be set to only send or receive 16 channels. This stems from the olden days, as the IF-FW/DM Manual says: "This allows restricting the number of channels coming from the computer to 16 for reduced host load, or setting the full channel count of 32. Especially at high sampling rates, if you don’t need the full 32 channel count from the computer to the mixer for a project, you will get better performance from your computer by setting this to 16."

 

[551Studios]

@Arjan P That being said, I've just now thought about the possibility of cascading 2 DM4800s together... I haven't been able to find much thus far, but if the 2nd machine is equipped with the firewire cable, is it possible to get another 24 inputs/tracks into the DAW via a separate Firewire chain...? My Mac Pro DOES have at least 2 Firewire ports, or does it not really work that way...? I've never had a problem with 24 channels of simultaneous recording, figured if there's a machine able to handle 48 channels of that, it'd be mine!

 

[Arjan P]

@551Studios I don't know anything Apple - and am limited in my knowledge about cascading two DMs, but if it would work the way you describe, you'd have 64 channels with two firewire cards (but indeed 48 analog mixer inputs). Maybe @cmaffia can tell you more, he has two DMs cascaded.

 

[551Studios]

Yeah, I'll have to do a little more reading on the Mac and DAW side of things I suppose, from what I've come across so far it appears that all 4 of the Firewire ports on my Mac are the same "bus", not sure if that would lend towards independent in/out for each Firewire channel and audio, or if the DAWs (Logic & Cubase) are capable of allowing and recognizing 32 Channels in from each independent Firewire port.

To piggy back on your post @Arjan P, I'd definitely make sure to add the IF-AN/DM for both boards if I end up with 2, mo' channels mo' betta ; )

 

[551Studios]

Can anyone comment on cascading? Or if it’s possible to get 2 FireWire ports taking in 32 channels each of audio simultaneously?

 

[mixerizer]

Just wanted to clarify - the title of your post is about getting more inputs into the DM4800. Your followup questions are about getting more simultaneous recorded tracks into the DAW from the DM - obviously related but a very different issue.

Higher speed Thunderbolt systems like MOTU and many others can serve 64-100+ channels to and from the DAW, but besides bandwidth the number of recording tracks is most dependent on disk speed and CPU. Given all the limitations I wouldn’t expect one FireWire Mac to be able to do the same using two simultaneous FireWire busses. If you need to track that much at once, perhaps grab an x48 to stay vintage or a thunderbolt interface compatible w your choice of DM ports and cards, and set up an aggregate device with it and the firewire card.

Thanks again for the info you found on the inputs issue.

 

[Arjan P]

I wouldn't worry too much about how taxing 64 channels of audio would be to a (relatively) current setup. Just a quick example: FW800 represents a max bandwidth of 98 MB/sec. At 96 kHz and 24 bits, that would allow for 358 channels of audio. Very theoretical ofcourse, but 64 is nowhere near this value.

 

[mixerizer]

Yup. How many tracks recording at once chokes the system will depend on a lot of factors. Also, max RAM helps always.

As an example, my MOTU 112d allows over 100 channels to and from the DAW, so big channel counts are definitely possible.

 

[mixerizer]

Quick update on 96khz recording and practical input/output maximums on the DM-4800:

1. DM TDIF-1 ports 1-3
- ( 24/24 @ 96kHz )
- can be used with an X-48, IF-AE8HR or other format converter(s).

2. DM expansion slots: IF-AE/DM (AES/EBU) , IF-TD/DM (TDIF) or IF-AN/DM (Analog) card
- ( 3 slots - 24/24 @ 96kHz )
- all three cards can provide 8/8 channels at 96kHz when used with compatible devices such as X-48, IF-AE8HR, other format converter(s) and interfaces
- Note: IF-AD/DM (ADAT) card apparently only supports 44.1-48kHz.
- could use a fourth slot as well, but reserving one for Firewire leaves 3 slots

3. IF-FW/DM FireWire card in slot 1 or 3
- ( 16-32/16-32 @ 96kHz )
- DAW returns from host

4. DM internal ADAT port
- ( 4/4 @ 96kHz )
- it’s there, and it’s four more channels at least

5. DM mic/line inputs (analog)
- ( 24/24 @ 96kHz )
- analog sources

6. Last, in a pinch, one can make use of the DM’s assignable sends and returns (analog).
- ( 8/8+ @ 96kHz )

Total:
- When recording at 96kHz, up to 108 96kHz inputs and outputs (~76 digital, 24+ analog) within the DM-4800’s max of 64 input channels.
- (Digital only) Using TDIF, internal ADAT and four slots (no FireWire), that’s 60 physical 96kHz digital inputs, with a total of 64 including the DM’s DIGITAL IN 1 & 2 inputs (or its two stereo internal FX returns). Reserving one slot for FireWire means u have 52 physical 96kHz digital inputs.
- Based on the board’s FS CONVERT settings, if you use ADAT cards those 44.1 or 48khz inputs will be converted up to the board’s sample rate.

192kHz:
- Given the board’s longevity, I am okay with 192kHz not being available.

 

[Arjan P]

- Given the board’s longevity, I am okay with 192kHz not being available.

192 kHz is for dogs and snobs anyway...