Connecting pre amps to HD I/O

[Timbuck2]

Hey all.

I'm new to the Native/HDX setup. I'm now looking at saving up for a Native system. I know this may sound silly to you guys, but would anyone be so kind as to give some info on how the wiring for connecting preamps to the HD I/O works?

I understand that it uses DB25 for analog ins and outs and AES/EBU for digital, but obviously different preamps have different connections. So for example, a True systems P8, it's clear that I could use a DB25 to DB25. A Focusrite Octopre, I could use a DB25 - TRS 1/4". But what about an API 3124? Or a UA solo? I see XLR outputs on these, but have no idea what cable I'd put between them and the I/O. Or an SSL Alpha Channel, which output seems to be one single jack socket.

Again, apologies if I sound silly, but I'd really appreciate some info.

Thanks guys

[nst7]

You would have to pick and choose and then buy the right cable. Besides DB25 to DB25 and DB25 to TRS 1/4, you can also get DB25 to XLR Male or XLR Female.

The only way you could mix and match would be to get cable adapters. For example, if you had the API 3124 with 4 XLR's, and then you had another 4 channel preamp with TRS, you would get a DB25 to XLR snake, and then add 4 TRS to XLR adapters, or something like that.

So you would need to plan ahead and really think about what you want to use and how to set it up.


It should also be noted that the UAD Solo is not a preamp, it's an interface that has preamps built in. There is no way to use just the preamp portion and then go into an HD IO. If you want their preamp emulation, you would be better off getting an Apollo and going digital Adat into the HD IO.

Also, the SSL Alpha Channel has a digital Spidf out, which you would plug into the Spidf in of the HD IO, giving you better quality than the analog outs.

[Timbuck2]

Thanks for the detailed response, much appreciated.

Yeah I thought it'd be a case of finding the right cable. Something I'm unclear about though is the 8 way DB25 to XLR snakes, I've only ever seen them in 8 way, however I've seen many preamps with less than 8 outputs, like the API 3124 for example. So I just wondered what the remaining XLR's on the snake would be used for, if not to connect to something else? Could they just go unused? Your suggestion of adding an adapter cable makes perfect sense if I had an additional preamp, but what if I didn't have another preamp?

Sorry for straying from the topic!

[nst7]

Yes, the other xlr's can remain unused, or use them with other hardware, like one or two channel preamps, etc.

[mesaone]

Originally Posted by nst7

he only way you could mix and match would be to get cable adapters. For example, if you had the API 3124 with 4 XLR's, and then you had another 4 channel preamp with TRS, you would get a DB25 to XLR snake, and then add 4 TRS to XLR adapters, or something like that.

Or have it custom made. Or remove the connectors that aren't the desired type and solder on new ones of the correct type.

[jbrown7282]

I would go into a Patchbay for all my analog stuff.... Either DB25 to DB25 or DB25 to TRS.... then from the patchbay make all of my hardware connections.... But like someone said.... you will have to plan out how you want to make the connections...

[albee1952]

With an Octopre, I would connect via lightpipe My setup is based around a pair of HD IO boxes in the standard 8x8x8 configuration. First unit gets 8 channels of analog preamps via an XLR-DB25 cable and 8 channels from Octropre MK II Dynamic on lightpipe. second HD IO gets several more analog preamps(again, XLR-DB25 cable) and 8 channels of a Midas XL48 via lightpipe. When adding digital sources(Octopre and Midas), clocking is crucial. The Octopre also has a returning lightpipe connection(which handles 4 headphone mixes) and clocks to that lightpipe input. The Midas is clocked via a BNC WordClock cable from the main HD IO box.

A side-note on this clocking setup, since I usually run everything at 48K, if I open a 44.1K session, the Octopre and Midas don't function unless I set them each to 44.1K

[Timbuck2]

The two pres you mentioned (Octopre and Midas XL48) have both analog AND digital output connections, am I right? So because neither is solely digital, could either be connected to the analog card of the 8x8x8 instead, as analog pre, to free up inputs on the digital card?

Also, let's say I want to use a Midas XL48 with my 8x8x8. Could I use both the analog and digital outputs it simultaneously? If so, what would the benefits be?

I haven't even starting looking into clocking yet. One thing at a time for me!

[mesaone]

Originally Posted by Timbuck2

Also, let's say I want to use a Midas XL48 with my 8x8x8. Could I use both the analog and digital outputs it simultaneously? If so, what would the benefits be?

I own an XL48. It actually can be used as a 4-way 8-channel mic splitter:

1. ADAT outputs ch 1-8 at the optical port (ch 1-4 if using SMUX)
2. AES DB25 outputs 2 copies of each channel (the 25-pin connection is 8x 2-channel outputs, preamp ch1-8 on connectors 1-4, and preamp ch 1-8 again on connectors 5-8)
3. there is an 8-channel analog DB25 output as well

It also comes with a high quality 75 ohm DB25-to-XLRM snake, which can be used for either analog output or AES outputs.

Edit: I'm VERY happy with this thing, it's been road tested and performed admirably. My two complaints: (1) The 40mm fan was loud, I had to replace it - which I don't recommend for everyone, since you will void your warranty. (2) The gain knobs have that common problem with many audio taper pots where the last 10% of the taper represents more gain than it should, so fine-tuning high gain settings can be touchy. But the preamps are quiet, so this isn't such a huge deal, especially if you're recording at 24 bit or higher.

[albee1952]

Yes, the XL48 and Octopre Mk II Dynamic have analog outputs and could feed via analog into an HD IO box with available inputs. Just consider a few details you may not yet be aware of:

#1-HD IO boxes can each pass 16 ins and outs at a time, total.
#2-with Octopre Mk II Dynamic, using the analog outputs will remove the option of using those 8 outputs FROM Pro Tools(these outputs are EITHER the 8 preamps out, OR 8 line outputs from PT).
#3-yes, the Midas can connect via AES(but I see no sonic advantage unless you wish to use high sample rates). Lightpipe works dandy at 44.1 and 48K
#4-there are 3 versions of the HD IO; 16x16 analog(all analog ins and outs on DB25 connections), 8x8x8(8 analog IO and 8 digital IO), and 16x16 digital(which has no analog connections at all)