Digital audio patchbays?

Hi,

I'm beginning to find myself with a significant number of ADAT and S/PDIF connections that need to be re-routed from time to time and some sort of patchbay would be ideal for the job, so I've been looking around to see what's available. The answer seems to be: not very much. There are two older devices that come up second hand from time to time in the shape of the Fostex DP-8 and the Midiman/M-Audio Digipatch, either of which would do the trick nicely. However what I've read seems to suggest that neither will handle 24 bit signals (though it's rather difficult to be sure since the published specs for both are totally silent on the subject).

I have two questions if anyone can help. First, does anyone know whether either the DP-8 or the Digipatch will handle 24 bits? Second, what else is out there in the way of such patch bays.

TIA,

Chris

Found this, FWIW: Note: The Litepipe protocol used by the Digipatch, known as DT-16, is a format intended to support 16-bit Type I ADAT devices. Other Litepipe formats are not guaranteed to work reliably. All coaxial S/PDIF and Optical S/PDIF (TosLink) are fully supported.

Chris

the digipatch works better than the DP8 though..... (i've had both) also look up frontier designs product range.... can;t recall the name of it offhand, but they do a 24 bit jobbie.... and it's very good.

The lack of affordable patchbays is one of the great mysteries in digital audio. How do people connect their gear? Do they constantly unplug and reconnect the leads?

Only in desperation. TBH, there's been quite a few times when I've been transferring old material from a hardware disk recorder, where hooking up the digital and dealing with sync and all that is just a PITA. So I just transfer it analog- and it sounds fine, extra conversions and all !

idris y draig wrote:the digipatch works better than the DP8 though..... (i've had both) also look up frontier designs product range.... can;t recall the name of it offhand, but they do a 24 bit jobbie.... and it's very good.

Thanks for this. I looked up the Frontier Designs thing - at's called the Apache. Only downsides are that it's ADAT only and out of production .

Strangely enough a Digipatch came up on ebay tonight and I bought it for 90 quid. My reasoning was that I've probably got ADAT reasonably well covered by the Profire Lightbridge I bought recently, but the Digipatch is still, as well as ADAT, a six-way S/PDIF matrix. And that is going to be sooo useful. So thanks for your help, it did help me make up my mind.

Cheers,

Chris

I've got a Digipatch I tracked down on ebay a few years back, but it's broke - note - do not use a power supply that isn't the correct one - it blows up a chip on the motherboard.

I need to get it fixed just haven't got around to it yet. While it was great and really useful (changing the routing of various gear from buttons in Logic was super cool), there was some gear that just didn't seem to work, and I have less need to interconnect loads of digital gear (back then I had a stand alone hard disk recorder, dat machine, reverb unit, computer audio interface, couple of modules with digital I/O and so on)

It's probably more practical to have an audio interface with multiple digi I/O for most of use these days, I expect.

I might have one of those chips knocking around Desmond... from the last time i bought some to repair a mates one.... it's yours if i can find it and you're happy fitting it....

desmond wrote:It's probably more practical to have an audio interface with multiple digi I/O for most of use these days, I expect.

I agree, which was why I went for the Lightbridge. But it isn't very good on SPDIF, which is where I hope the Digipatch would help. Hadn't thought of controlling it from Logic. Done by sending it messages over MIDI, I presume. Thanks for the thought.

Cheers,

Chris

For anyone else looking for a digital router, for small/medium sized units (8-256 i/o), I usually look first at Z-Systems who make a very useful range of products covering various combinations of Lightpipe, S/PDIF, and AES/EBU i/o, including some combination jobbies with mixed i/o.

Another favourite is the Crookwood range. These products can be used to build routers/format converters and incorporate monitor controllers and A-D/D-A functions. They're not cheap (though not expensive for what they do and the quality involved) but are capable of top notch results and often find use in high end mastering rooms.

Once you get above needing about 128 or 256 i/o you're really getting into grown up stuff. These tend to be quite expensive but there are plenty of choices around. Try looking at the catalogues of companies which specialise in broadcast products like Kramer, Calrec, StageTec, etc..

One thing about a lot of this stuff is that it's relatively expensive to buy new as it's the kind of thing you either need, in which case you really need and will pay for it, or you don't, in which case you ...er... don't. When it's replaced/updated/liquidated, depreciation bites hard and it tends to be worth very little. Larger routers with new costs in the tens (maybe hundreds) of thousands can be picked up secondhand for small fractions of this (though it's rarely worth it as they tend to be rather cumbersome with installation costs commensurate with their new prices!). Products like the smaller Z-Systems stuff hold their value rather better but it's still possible to make a substantial saving buying secondhand.

On the discontinued/secondhand market, AKAI did a range of very useful digital (and analogue) routers, including at least one with a mixture of i/o types (DP88 iirr).

In some cases other options might work better; RME do a big range of boxes for routing/converting different formats. Often, routing isn't their primary role, and they're not perhaps as flexible as some dedicated routers, but they might allow one to combine routing with some other function like format conversion. e.g. Their ADI-648 MADI-Lightpipe converter incorporates an 8x8 lightpipe router (which can also split lightpipe signals), the ADI-642 AES-MADI converter has a full 72 point crosspoint router capable of reconfiguring MADI streams as well as routing signals to and/from the 8 AES/EBU ins and outs. (It's actually a 72x74 point as it allows pairs of signals to be routed to the headphone output for quick listen checks.) There's also the option in the RME TotalMix software to use a crosspoint router and/or mixer to move signals around.

Also, some multi i/o computer interfaces incorporate routing functions (either deliberately or as a by-product of other things). e.g. Lynx AES16. Given the ever falling prices and growing capabilities of computer hardware and software, it can be cheaper/more flexible/ergonomic to build some types of routers out of cheap computers filled with interface cards. Depends what one needs really.

To some extent, as people move to working more 'in the box' the need for dedicated routers is reducing, added to which, multichannel interfaces, often incorporating different i/o formats are becoming more common, so routing takes place more in the box too. That said, I still like hardware routers for some things, and if you want a quick way flexibly to 'patch' a few bits of kit, dedicated hardware routers can be hard to beat. Especially if they include other tricks like signal splitting and format conversion.

0VU wrote: One thing about a lot of this stuff is that it's relatively expensive to buy new as it's the kind of thing you either need, in which case you really need and will pay for it, or you don't, in which case you ...er... don't. When it's replaced/updated/liquidated, depreciation bites hard and it tends to be worth very little.

... Which tells us the gear was vastly overpriced to begin with - no?

How difficult can it be to make a box that has, say, 8 optical i/o and 8 SPDIF coax i/o, and write the software to interconnect between them?

Not as easy as you would think!

If those optical IO are optical spdif then it is not too bad, but if they are adat then you need some fairly sophisticated firmware (probably a gate array) to unpack the 8 channels and re format them if you are patching to spdif.

If everything is on spdif/AES3 in the same clock domain then it is relatively easy, but for anything else it gets hairy fast.

The majority of the cost in a facility router (I like the Grass Valley & Probel products, also SAS, broadcast tools) is in making something that is very highly reliable, these things get used in situations where being off the air costs north of a million an hour in lost revenue.
And no, I don't think they are over priced, you are talking about kit with redundant power, redundant processors and very heavy construction, that sells into a tiny market, these are not mass market 'prosumer' devices.
I will grant that they are so highly optimised for what they do, that they are of limited use outside a broadcast facility.

There is a small 16 * 16 AES3 effort from Probel that sometimes turns up on ebay for cheap that can be worth a look if you are running that format.

Regards, Dan.

No offence intended, but i gotta say that there are days Tui, when your complete naivety and ignorance about manufacturing and commerce amazes me.

it's a tiny specialist market, where very few buyers exist.... making production relatively expensive because of low numbers, and high investment and development costs, and resale value small because there are more potentially used items than buyers... especially given the number of closures the studio market has endured...

that does NOT translate in to "how hard can it be" , and "they're too expensive in the first place"

no matter what way you look at it....

1) it is NOT spectacularly easy.... especially without introducing clock jitter and drop outs...

2) aside from the R&D costs , tooling up a factory to produce these things, does not cost pennies...

a largely simplified scenario

for example, let's say a team of 3 people do all the R&D , and they each cost £40K per year, and it takes 1 year....

add the cost of premises, and facilities to that , and materials and what not, and you easily have a research/design cost of £200K

if you're only going to sell 1000 of them in total, that means a loading of £200 on the price of each unit.

it might cost £400K to tool a factory to produce them.

the materials per unit might only cost £40 ... but so far, before shipping and taxes, that's a loading of £640 per unit to be borne....

and , shock horror, companies are in business to make a profit... preferably a larger one.

so for something containing £40 of materials.... £1000 would not be an unreasonable trade cost.... then the reseller must make their profit.... and whammo you're at £1500 for what amounts to £40 of materials.

without anyone putting a gun to the buyers head, or ripping anyone off.

if you're lucky, then it becomes more popular, the market expands, and in the long run you sell more than the original target , at which point, the price can either come down, or the maker can enhance their profit margins .. provided it happens before the factory has to be re-tooled for other products.

the fact that the used market for outdated obsolete products (for example those that do not support higher sample rates) is worth very little has absolutely no bearing on the cost of new product.

+1 for the Z-systems stuff. use it myself and very impressed by it. Optipatch, Optipatch Plus and Z-8.8 are all strong contenders.

hugh

idris y draig wrote:No offence intended, but i gotta say that there are days Tui, when your complete naivety and ignorance about manufacturing and commerce amazes me.

I'm sorry to disappoint you. However, I think you're quite mistaken.

I used to own a device, similar to what I described earlier. I can't remember the make of it, all I do remember is, it was a blue, 1 RU box. I think it was manufactured in Korea, or something. It had optical and SPDIF i/o at the back, and various buttons at the front for changing connectivity. It was a neat little box, really, quite simple in terms of functionality, but pretty much what I was looking for at the time. It was cheap, too. I can't remember exactly, but certainly not more than a few hundred dollars.

If only...

... The thing would have been more stable. I remember that it worked OK for a few minutes, then crashed. I had to restart it, wait for a couple of minutes, until it crashed again. Very frustrating.

In the end, I sent it back. What a shame, since the basic idea of the device was brilliant. However, execution was obviously lousy.

That was nearly 10 years ago, when I was still living in NZ.

So, to my mind, it can be done, yet, for some reason, none of the established brands have decided to give it a go.

I do not believe such a device would be difficult to conceive or costly to make, considering that many audio interfaces have digital routers built in as well.

In fact, I'm currently using my Eventide Eclipse as some sort of a patchbay. For FX, it is hooked up via ADAT, but for routing the digital signal from my Apogee Rosetta AD into my RME Multiface 2, I regularly use the AES input on the Eclipse.

To be practical, a digital patchbay wouldn't necessarily need to provide an unlimited number of choices for routing the signal, or fancy mixing capabilities. All it would have to do is allow the user to select one of 8 inputs, and route the signal to any of the 8 outputs.

Tui wrote:If only...

... The thing would have been more stable. I remember that it worked OK for a few minutes, then crashed. I had to restart it, wait for a couple of minutes, until it crashed again. Very frustrating.

Well I rather think you've answered your own point!

Otherwise, thank you gentlemen. This has been an illuminating discussion. Hopefully the Digipatch will meet my immediate needs, but I've bookmarked this in case a time comes when it no longer cuts the mustard.

Cheers,

Chris

Our (now retired) detangler is a fantastic box for all sorts of annoying connection stuff. They can be bought for less that a grand now, I believe.

We stopped using the z-sys when converters reached a reasonable standard and tend to just D/A-A/D these days, it's faster.

On rare occasions it comes out from the storeroom so we're keeping it but it seems we don't need it as much as we used to.

ConcertinaChap wrote: Well I rather think you've answered your own point!

I know.

Still, I can't see why there are no simple and affordable patchbays on the market.

It used to be the same with hardware DAW controllers. I remember getting an earful at this very place for suggesting it should be quite possible to build affordable devices that don't cost thousands. That was a few years ago, when the Mackie Control was considered affordable and a bargain by some.

Today, you can choose between a whole range of reasonably well-built and truly affordable controllers.

It is true, though, that more and more mixing is done entirely ITB, and hardware FX units - prime candidates for connecting via patchbays - are being phased out. Think Lexicon, for example.

Tui wrote:
Still, I can't see why there are no simple and affordable patchbays on the market.

If there was really a market for them then a consumer electronics company would have had Glenn Zelnicker design them a unit that they could manufacture cheaply (in the same way that Focusrite took Mike Kemp's dynamic convolution and turned it into the Liquid range).

Cheers

James.

For completeness, here is one other bit of kit that I have found: TC Electronic Konnekt x32. Combination of digital patchbay and audio interface with a few extra bells and whistles. Cost about 1k. Looks pretty neat. Currently out of my price range but one day, who knows?

Chris

I was on a similar search a couple of years ago - looked at the Frontier Apache, but ended up with a Friendchip Digimax; much more flexible system as you can swap out modules to cover ADAT, SPDIF, AES etc. Full recall of patching setups from my PC desktop via MIDI. I got the rack unit itself from eBay, but all of the modules were freely available on Thomann.
Worth a look.

James Perrett wrote:

Tui wrote:
Still, I can't see why there are no simple and affordable patchbays on the market.

If there was really a market for them then a consumer electronics company would have had Glenn Zelnicker design them a unit that they could manufacture cheaply (in the same way that Focusrite took Mike Kemp's dynamic convolution and turned it into the Liquid range).

Cheers

James.

Up till very recently, I'm confident there would have been a market for it. Not so much now, I guess.

Still, if you have a couple of FX boxes, external AD/DA converters, and perhaps an ADAT machine you keep for location recording, most interfaces won't allow you to connect all of it. You'll either end up unplugging and reconnecting a lot, or you throw in the towel and use some spare analogue i/o, which, of course, defies the purpose.

I can imagine there is still a number of people that own more digital boxes than could be simultaneously connected to their interface, yet not enough to justify purchasing a $1-2000 router that has all bells and whistles.

Personally, I'd hate spending that amount of money on something that doesn't make a sound.

Tui wrote:Personally, I'd hate spending that amount of money on something that doesn't make a sound.

Chris

Clever boxes aside, if all you want to do is route signals from place to place, without changing them from one type to another or splitting them to multiple destinations, you could just use an appropriate passive patchbay, e.g. BNC for S/PDIF, XLR for AES (or even PO316 - it's less 'to spec' but ime works fine in almost every circumstance), or TOSLink for Lightpipe signals (though TOSLink connectors tend to be crap and wear out very quickly). They won't format convert, etc., but they'll let you route digital around in the same way as analogue. If you're running long lines or have finicky/sensitive equipment you might run into problems with the extra connections and/or cable lengths involved but in a typically smallish home studio you should be able to make it work.

I know that in several places I've built/worked we've routed AES/EBU and optical signals over tens/hundreds of metres without problems (PO316/XLR patching for AES/EBU and LC/SC with an appropriate glass fibre for opticals). One mastering facility contained over 4000m of AES/EBU cabling, with all but one room using PO316 patchbays for internal routing and access to tie-lines (the other room used XLRs) and about 1500m of optical fibre. You can also patch AES/EBU using RJ45 Cat5/6 data patchbays but I've only done this a few times (so far without problems) and don't know how common a practice it is.