analog router patchbay

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

kibadachi

Well-known member
Joined
Mar 25, 2009
Messages
53
Location
The Netherlands
I am interested in buiding an analog router patchbay with presets. Similar like the Z-Sys detangler( in an analog version) or in the early days the Intone\Anatek Maestro.
Purpose would be to switch gear order in a mastering chain without patching cables.
Anyone aware of schematics for a starting point?


Jeffrey
 
The schematics would be quite straightforward, so first look at the block diagrams of the mastering products from Manley and Dangerous.  From there you make your own schemos with the simple building block involving two DPDT relays per device.
No schematics to blindly copy that I know of. . .
Mike
 
The only products I'm aware of that do this with passives are the offerings from Crookwood. Everyone else has a fixed insert order. You would need to know something about programming logic.
 
Thanks for your replies,


I will look in to the Manley,the Dangerous and the Crookwood as you both suggested. Too bad i am not into programming logic. If other folks are interested i will post my findings and progress here.


Grtx,

Jeffrey
 
The Manley and Dangerous offer one pair that can swap position in the otherwise fixed chain, like 1-2-3-4-5 or 1-2-4-3-5.
Paul, would a second swappable pair cover all possible needed mastering equipment chains?
Mike
 
sodderboy said:
Paul, would a second swappable pair cover all possible needed mastering equipment chains?

Mike, I almost never switch the order of my gear but I don't have very much. I don't think you could make something that would satisfy everyone. For routing flexibility and interface design I think the Crookwood wins hands down. It is very customizable. The others are what they are and if they suit your needs then they're great.
 
It's possible to design & build quite a complex router without the use of software or programming.

Just by using logic gates and relays/MUX chips it is possible to make a unit that does, say, switching for 8 effects units placed in any order. (for the logic 8 relates to a 3-bit code).
Front panel controls per effects unit would be a rotary switch to select the position in the chain and a latching pushbutton to select the effect to be in-circuit or bypassed.

As well as the basic logic circuitry, (about a dozen gate chips) you would need either:
a. Purist's hard-switching using a large number of relays.... in the region of 288. This assumes 2-pole relays and a balanced stereo path. All signals could be kept at line level.
b. 32-off 1-into-8 analog MUX chips plus all the input and output buffers to convert to/from virtual earth to line level (which could easily be balanced or unbalanced).

Either way it would be a stimulating challenge.

Gareth.
 
i read the info about the Crookwood. They put a lot of effort into making this a reliable and intuitive solution.
I guess i prefer the purist way with relays although it could be a unique selling point having the best sounding patchbay ever ;D
Do you have any recommendations how to approach the earth connections to prevent groundloops?
 
I'll probably get crucified for this, but the easiest way to avoid ground loops in this situation is to not use them.

Sounds kinda outlandish, but I can be almost 100% certain that if all of your kit is using balanced line inputs and outputs you can get away with not using them. Works the world over in TV and Radio stations.

If you don't like the idea of having all your audio paths unshielded (understandable in a mastering situation) you can connect the shield at the equipment end only, and leave it disconnected where your equipment connects to your router/matrix.

This only works on balanced line level audio. It does kinda work with dynamic mics, but the noise you pick up is brutal. It will never work with phantom powered mics.

Usual caveat....under no circumstances should you disconnect the mains earth/ground. This is there to help you avoid death, don't risk it.
 
I think to some extent the rule of KISS applies.  When you factor in design time, build time, build troubleshooting (now and potentially down the road), small patchbay would be FAR simpler, and probably at least as easy/fast if not easier/faster.  Is a more "elegant" solution really more elegant if it's not better in any way other than being more complicated?  Not trying to talk you out of this, necessarily, and there are very likely things I'm overlooking.  Just playing devil's advocate.
 
bahrens said:
small patchbay would be FAR simpler,.

I agree. I'm a big fan of 5 pin xlr's. Patch everything in stereo.

You could also use rotary switches. Each piece of equipment would need a position on the switch and you would need as many rotary switches as pieces of equipment. You could then choose any piece in any position. Watch out for feedback loops...
 
I agree with the idea of keeping it as simple as possible. The reason why i would like to accomplish this way of patching is to have less technical distraction. If i can realise an insert by the push\turn of a button i can stay in my listening spot and continue feeling the music instead of putting focus on technical issues. I realise getting distracted is my own problem but there is no DIY project to bypass this.
So for now i will look into the suggestion to use rotary switches. I guess i can always expand with relays later or combine both.
Any recommendations for rotary switches and relays?
When i use relays would you recommend to use a separate board for each channel(having the oppurtunity to expand to multichannel) or would it be better to keep both channels on one board?
 
It;s doable with a LOT of relays and works great! I have mine running for some time now and it still works great.
Check this page for more info and pics: http://www.groupdiy.com/index.php?topic=8360.80
I don'tg have any schematics, just out of head building and logical thinking
 
I did mastering for several years as a profession, nowadays a bit more sporadically, and never felt the need for a router like you describe. I use an xlr patchbay. Simple, robust, and adequate. I like Paul's idea of 5-pin xlrs! I might have to get with that.
 
Back
Top