Hi everyone

I'm looking for an unusual product I know, but here goes anyway... If I don't ask I won't get!

We now have an AV install project that uses a MacBook Pro as the main playback source for presentations and video content. I'd like to have a better quality audio interface than the standard unbalanced on-board analogue audio on a flimsy 3.5mm connector. Optical digital out is available via the same connector, and I guess would be less flimsy over time than relying on metal contacts to stay in the right place/shape for the life of the machine.

I'd like a rackmounted device to plug into the mac, so that the audio output side is wired permanently into our PA system audio patchbay, with some form of digital connection presented to the mac side. Smaller non-rack-mounted devices would do the job and there are many options - but I want a much neater, more obvious and therefore more reliable/hard-wearing solution than a string of disgusting flimsy boxes stuffed out of sight down the back of our racks.

Thinking some more: Having more than 2 channels available gets too complicated for small-brained users. The device is to be primarily used for playback - recording is covered more than adequately elsewhere. I can see three fairly universal ways of connecting such a device to this kind of machine: USB, Firewire, or perhaps even the aforementioned optical digital audio output. As previously hinted, I don't want a multi-box solution - the more devices in the signal chain the more problems we'll have to trace when it goes wrong.

The closest solution I can find is a Sonifex Red-Box DAC, that accepts AES/SPDIF in (XLR or RCA) but that will require an optical-electrical conversion stage so it doesn't really fit the requirements - but it's the right idea if it had an on-board optical input.

Can anyone think of a solution for... (a lot) less than £400?

C

Obviously leaving sound quality to one side for the moment, but won't you have a similar problem with an outboard solution? I.e. you'll be dependent on the metal contacts in a USB or firewire socket staying in the right place/shape for the life of the machine...

It might be desirable to connect external equipment via an optical connection - as this would preclude any interface noise problems often experienced with laptops and 'electrical' interfacing.

However, optical cables have to be fairly short - so the rack unit would have to be physically close to the computer.

Consider the Behringer Ultramatch SRC9624 - which, as far as I am aware, has no competition - certainly not for the sub £100 price of this item. It has a variety of digital inputs (but no USB) - and contains D/A convertors with balanced audio outputs at line level on XLR's.

You must mean the Ultracurve Pro not the Ultramatch (It doesn't exist). It has a Digital S/PDIF, AES/EBU, analogue, midi and World Clock In.

It is a nice unit but not sub £100. The best price I have found is about £219 on Dolphin Music.

Josh

Yes, but experience tells me that the 3.5mm connectors fail more often than pretty much any common connector type I've used with any regularity. And anyways - it's the increased audio quality I'm after, as much as (if not more than) an increased connection reliability.

EDIT: Oh, and no Behringer or similar please...

Oh yes it does. I've got one. Numbers a bit wrong though.
http://www.behringer.com/SRC2496/?lang=ENG
And there it is on their website.

Works pretty well, I'm fairly happy with the quality of it.

I swear that wasn't there 5 minutes ago.

Josh

It does exist - I have one - and paid about £80 including VAT and carriage for it......!
Ultramatch Pro SRC2496
I seldom recommend Behringer stuff for serious applications - but I am using the device as a test signal source for 96kHz sample rate and 16, 20 or 24 bit word generation for a research project - so not 'mission critical'.....

So if you can't find it with google it doesn't exist? Never mind.

Back on topic. What about a rack mount firewire interface? I've had a search and can't find one for less than £300, bit steep but so many extra features.

Failing that (and it's not rack mount without a shelf..) you can pick up Cambridge Audio DAC magic 2 (euggghh, did I just point some one at a hi-fi unit?) specs here http://www.gbaudio.co.uk/data/dac2.htm

But really just look after your kit, don't use heavy mini jacks, a cheap di and you should be fine for years, it's time to employ the KISS principle, and keep your dosh in your pocket (or spend it in the pub...)

The advantage (and disadvantage) of the USB/Firewire option though, is it will work on the digital cliff principal. The audio being carried between the laptop and interface will be in a digital format, so as long as the 1s and 0s get though and can be correctly interpreted at the other end, you get a full quality signal, unlike the jack which may tarnish, pop, crackle or become loose. The downside is the digital either works or it doesn't and you won't really know when its close to failure, it just won't work. The same principle applies to DVI, SDI, AES and other similar systems.

Wait. Optical cables have to be short?! Tell that to Virgin Media

Very funny. Their 20Mb fiber cable is very thin.

Wouldn't a Optical cable be more susceptible to damage tho?

Josh

I'm sure that most people viewing this forum will be well aware of the difference between the plastic fibre driven by a LED used for SPDIF data and 'real' glass fibre used for telecommunications driven by a laser!
I have just checked in a few catalogues and see that TOSlink type fibre cables are available in lengths up to 10 metres - but as this type is normally used for Hi Fi interconnection, much shorter lengths are the norm. Higher quality glass fibre types are also made and several feature gold plated metal bodies. But we won't go there!