DIY with DB-25 ? Rack panel, not snakes

[john61ct]

I've been looking for high SQ / low price per analog port secondhand interfaces and ADAT A/D converter "breakout boxes" for DSP use.

I found some units that use DB25 TASCAM pinout connectors rather than hosting the ports onboard, very nice feature sets lotsa ports, going for cheap

And then found out that cable snakes and patch boxes etc cost (a lot) more than all the fancy electronics!!

Inputs are 8x SE RCA, outputs 16 or 24, mostly XLR but maybe some will be SE RCA will be using a mix of amps. The SE <–> balanced voltage / buffer I've planned for, this is about the physical ports / jacks wiring only.

What I'd really like are a couple rack panels or DIN rails, ideally the DB-25s right there in the panel, each broken out to 8x ports.

I want to customise the port type, respecting XLR spec of sources being male, sinks female.

Neutrik combo is only good for inputs, going to sinks, what is used for going to the amps, I need a 1/4" adapter for each output channel?

It amazes me how much these purely mechanical items add up!

So, I'm thinking a rack shelf? better a drawer, with a spaghetti mess of individually wired DB25 breakouts / Euro blocks, stock cables one end chopped off, maybe each 8-port "section" stuffed into a box.

I'd rather not learn to solder nor get into 3D printing both new rabbit holes...

Suggestions please?

 

[john61ct]

OK, topic is DB-25 TASCAM pinout (AES59) wiring for 8x balanced analog

not digital (Coax S/PDIF nor AES/EBU)

I have come across the AES-72 (type 1, "audio-over-CAT") standard for wiring 4x balanced audio channels into a single RJ45 connector & standard STP (Shielded Twisted Pair) Cat5e/6 cable

which are so much easier & better than Euro blocks or (dog forbid) DIY soldering

HOWEVER only 8x wires total per RJ45, 2x wires per channel, so there is no actual wire for each channel's "Pin 1"!

Instead, all channel PIN1 / shields are combined and carried across the single outer foil shield of the STP CAT wiring and a drain wire to chassis ground at both ends

Is there any downside going this way?

I have lots of experience doing LAN cabling, so just paying for the DB-25 to AES-72-1M adapter at one end and 2x breakouts (stagebox or "last foot fan-out" cables, can be custom) at the other

I can DIY the rack patch panels & everything in between, at custom lengths.

 

[Kal Rubinson]

nstead, all channel shields are combined and carried across the single outer foil shield of the STP CAT wiring and a drain wire to chassis ground at both ends

Is there any downside going this way?

I have been doing this without problem for the past 3 years.

 

[john61ct]

Noice, tx much

 

[john61ct]

To expand, coming from DSPi project, which enables ADAT in and out, 8x channels per Pico!

Introducing DSPi | A powerful, user friendly and open source DSP for less than a cup of coffee

From Google, please anyone fact check Reception (ADAT In) PIO architecture lacks the asynchronous oversampling arrays, Phase-Locked Loops (PLLs), or delay-locked loops (DLLs) necessary to track and lock onto this incoming bit phase dynamically. data bits will arrive at the Pico 2’s GPIO pin...

www.audiosciencereview.com

I want to standardise my infrastructure - snakes to rack patch panels, stage boxen...

using shield-grounded 100Ω STP Cat5e (or Cat6) wiring, and metal Neutrik etherCON RJ45

a pair of which (8x channels) converts with standard adapters to DB-25 (AES59)

servicing both analog balanced (AES72) and digital (AES3-2003 Annex D, also S/PDIF via 75Ω BNC balun converter jacks)

So XLR adds bulk + an extra conversion step, really looking for a compact 8ch solution at the Pico

one for input and one for output and lining up with a corresponding optical ADAT for each.

can breakout to one CAT line per pair when needed at the endpoints, XLR or whatever is needed there.

Ideally someone will just sell on Tindie, a case with the boards and jacks, USB data and power ports, all set ready to mount the Pico 2

Even without the DSP functionality I believe just as DDC would be commercially viable not just "Bidirectional ADAT – AES/EBU"

but different flavours of "Bidirectional ADAT – S/PDIF"

some more "meta" thinking

Introducing DSPi | A powerful, user friendly and open source DSP for less than a cup of coffee

Found this on Ali Thanks, but like I said, this gets expensive doing it pairwise when the goal is ADAT integration, 8x channels in each direction to continue here https://www.audiosciencereview.com/forum/index.php?threads/diy-with-db-25-rack-panel-not-snakes.71801/post-2653270

www.audiosciencereview.com