$8000 A2D/32 + D2A/32 or Digital Control of Analog Patch Bay or...?

[velo]

I suppose there's nothing special about the situation I am in. I've got a quality digital interface (RME) and a lot of vintage analog gear that surpasses my current digital ADC I/O.

I would like to figure out a strategy toward full recall of analog routing, at least, before I ponder robotic control of analog pots.

I see RME has a nice $4000 32 A2D and a $4000 32 D2A. If I sunk 8K on these I am sure it would enable me to route anything to anything and I would have a solid RME routing capability via TotalMix FX enabling hardware DSP to do (almost) everything in the analog domain.

But that $8000 may be a bit much for me to stomach so I am pondering other ideas. Boiling this down to a minimum requirement, it would be to enable me to route to/from all analog gear and A2D/D2A without having to rewire anything. I note that such a goal would also still work for direct analog-to-analog routing even if one day I did decide to acquire the extra 32 channels of RME ADC.

But I have a few questions.

1) Do the small delays in the DSP in this kind of routing add up to anything undesirable?
2) Is there any loss of or gain of mojo, heheh totally subjective, in having multiple D2A and A2D zig-zagging?
3) Would I be better off looking for a way to route analog gear with some kind of digital controlled patchbay that might minimize the number of ADC hops?
3b) What are the common solutions for digital control of analog routing?
4) What other questions should I be asking?

 

[velo]

Should I be looking into mercury wetted reed relays?

 

[velo]

https://hackaday.io/project/46280-muffsy-stereo-relay-input-selector

 

[Brian Roth]

Panasonic TQ-2 relays are well respected. The gigantic Amek 9098 desks ("by Rupert Neve the Designer") used a bazillion of them.

Bri

 

[velo]

Panasonic TQ-2 relays are well respected. The gigantic Amek 9098 desks ("by Rupert Neve the Designer") used a bazillion of them.

Bri

ok well if Neve then...

I was just thinking about a massive array of relays.

1. O(n*m) complexity. Adding one input costs n. Adding one output costs m.
   
   
2. ...even though the grid will never be filled and there can only be one intersecting choice.
   
   
3. This almost needs some other kind of mechanical solution.
   
   
4. Why have nm relays when there will only be MAX(n,m) on with nm - MAX(n,m) off ?
   
   
5. Modify a big plotter bed with pen arm retrofitted with cable insertion/removal robot?

 

[Brian Roth]

Ignoring relays for a moment, I used to design large distribution systems for analog video production facilities. Besides routing video we also had to route audio as well. Some of the facilities required huge XY matrix systems...like 64 x 64. That would be 5376 crosspoints for the video, and twice that for stereo audio. Attached is a snapshot I took in 2009 of a video router at WRC (main NBC station in Washington DC) and NO, it wasn't my project! Doing a count from the pic, that looks like a 40x40 and it WASN'T the only one there.

I DO understand your point, however...and I burned some brain cells to simplify that situation....but to no avail.

 

[totoxraymond]

The matrix switcher i was working with when I was assistant in a post production facility had resolved this somewhat with something they called "path finding". I remember some times when many analog connections were used between rooms/machines, we could run out of available pathes and had to clear some manually.

Most of the connections were SDI or AES/EBU at that time so only the auditoriums and older VTR had a need for analog connections anyway.

Yet I don't know how they managed that internally.
And i can't remember the brand of that switcher...


Thomas

 

[velo]

The matrix switcher i was working with when I was assistant in a post production facility had resolved this somewhat with something they called "path finding". I remember some times when many analog connections were used between rooms/machines, we could run out of available pathes and had to clear some manually.

Most of the connections were SDI or AES/EBU at that time so only the auditoriums and older VTR had a need for analog connections anyway.

Yet I don't know how they managed that internally.
And i can't remember the brand of that switcher...


Thomas

I suppose that parallels why the Internet was created--a general solution for routing comms from anywhere to anywhere without the combinatorial switch explosion. That led to replacements for switchboard operators. Beyond that, it was a solution for redundant routes in case of unintended partitioning.

 

[totoxraymond]

Thinking about it:

Assuming that a well designed patch-bay should be half-normalled in an effective way. (ie your favourite comps and eqs are chained in your favorite way).

Then, your matrix need a smaller number of paths.

example: a patch-bay with 32 I/Os might only need 8 patching differing from normalisation most of the time. (25% of total)

then you "only need"

i*p +o*p + i + o = r

with : i= number of inputs, o = number of outputs, p = number of paths, r number of relays.

in our example:
32*8 + 32*8 + 32 + 32 = 576 relays. compared to i*o= 1024 relays.

I think it's even possible to lower that count even more with some amount of compromise.

But i'm not going to go that route, patch-bays are fine for me.

Cheers,

Thomas

 

[HP200CD]

Velo,
Are you are familiar with the Flock Audio line of digitally controlled analog crosspoint patch bays. Available in 32, 64, or 128 points, and recallable via a Mac/Windows app and a USB connection.
https://www.flockaudio.com/https://www.sweetwater.com/store/manufacturer/Flock_AudioSometimes it does not pay to DIY a brute force solution, when some else has already done the grunt work.
regards, Ted

 

[velo]

Velo,
Are you are familiar with the Flock Audio line of digitally controlled analog crosspoint patch bays. Available in 32, 64, or 128 points, and recallable via a Mac/Windows app and a USB connection.
https://www.flockaudio.com/https://www.sweetwater.com/store/manufacturer/Flock_AudioSometimes it does not pay to DIY a brute force solution, when some else has already done the grunt work.
regards, Ted

Now I am aware. Thanks

The UI is like an analog version of TotalMix FX. Probably that is the perfect solution for the analog side, at least the routing.