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Compact balanced connectors

A

ai1

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Two years ago I have built a 12ch amplifier using 3e audio modules. It is working flowlessly ever since.
However, 12 xlr connectors produced quite a bit of clutter and ate significant space of backplate (I use the HIFI2000 2U enclosure from audiophonics.fr).
IMG_20210831_183427.jpg
I am looking for alternatives to save some space to eventually add a fan, but I would like to keep balanced connection between MiniDSP 4x10 and the amplifier (I have not tried unbalanced yet, and because balanced is here, utilizing it seems reasonable). That being said, as far as I understand, my options are
1) 5 pin stereo XLR connectors
2) 3 or 5 pin miniXLRs connectors
3) 3 pin TRS
4) ...
5pin XLR looks as an interesting option: not only using it would allow to divide by 2 the surface used by connectors, but the wiring will also become simpler in this case.
However, it looks like they are not really commonplace in audio, and I am wondering how "standard" 5pin balanced (stereo) connectors are.
I have found 2 schemas of the wiring of this connector
conn_xlr3_xlr5_001a.gif ECL-CDX5-2-2-B.png
which seem contradictory (unless I do not understand what is "hot" and what is "cold").
That being said, 110Ohm DMX cables with 5pin XLRS seem to be readily available, and I was wondering if these can be used for audio. I am thinking to give it a try--my cables are only 30-50cm long, but I would be surely happy to get an educated opinion.
 
Have a search for audio snake ethernet. Each cable can carry 4 pairs of balanced signals. If you are building everything on your own it makes most sense.
 
I would prefer smth which can be directly mounted on the ampifier backplate, would like to avoid making a special pinted board for this. And smth that will not cost 200$ for 12 connectors;-)

I was also thinking of smth like this as alternative:
connect.png
Yet, I was expecting something more standard.
 
Thank you very much for suggestions.
DB25 connector looks like a great option for a 8ch amplifier. Because mine is 12ch, I would have to use DB37 which is quite a bit bulkier than DB25.
DB37.jpg
Still, might be interesting, I have to see how big it really is, will try computer garbage can of my lab if there is one.
I am tempted to go with an rj45 patch cable. I could use 4(or 6) unshielded connectors or just 3 shielded ones. The latter would be ideal because I have 3 boards 4ch boards. I suppose I could use one of these connectors
rj45-neutrik.jpgrj45-neutrik-2.jpg
or just a simple jack
rj45.jpg
to pass "through the wall." However, I was wondering if the common shield (ground) directly connected to the enclosure (aluminum) throuh these connectors will not result in ground loops.
 
When using DB-25 (or DB-37), could I just use a ribbon cable inside the enclosure?
 
Yep, they have all kinds of things on the well-known site...
DB25-cable.jpgDB25-cable2.jpg
 
What happened to the old 5 pin DIN connector? There was a time when they were popular on amps for tape in and tape out.
 
restorer-john said:
DB-25 is as very well until you have to make the cable yourself.
Click to expand...
Agreed but, on the other hand, it is so standardized and common that you can easily purchase any configuration (M/F) or length you desire. :)
 
Kal Rubinson said:
Ugh. Flimsy and with unreliable physical coupling.
Click to expand...

Yes, the female connector had these strange pins that only made contact with a narrow area on both sides of the male connector.
I've seen versions where the females connectors had a sleeve that enveloped the whole pin, but that is not standard.
 
ai1 said:
5pin XLR looks as an interesting option: not only using it would allow to divide by 2 the surface used by connectors, but the wiring will also become simpler in this case.
However, it looks like they are not really commonplace in audio, and I am wondering how "standard" 5pin balanced (stereo) connectors are.
I have found 2 schemas of the wiring of this connector

which seem contradictory (unless I do not understand what is "hot" and what is "cold").
Click to expand...
The one on the left is more in line with standard XLR pinout these days (pin 2 hot), the one on the right might still have been based on pin 3 hot. Both would be entirely equivalent from a black box perspective though, only the wire colors would differ.
ai1 said:
That being said, 110Ohm DMX cables with 5pin XLRS seem to be readily available, and I was wondering if these can be used for audio. I am thinking to give it a try--my cables are only 30-50cm long, but I would be surely happy to get an educated opinion.
Click to expand...
Be careful though, it seems DMX cables are using as little as two actual conductors with 5-pin connectors at times, which is obviously not what you want.

ai1 said:
DB25 connector looks like a great option for a 8ch amplifier. Because mine is 12ch, I would have to use DB37 which is quite a bit bulkier than DB25.
Click to expand...
Anything wrong with using two DB-25s and leaving half of one unconnected (or for chassis ground only)? That's still way more compact than what you have now, and I suspect more so than you actually need.

kchap said:
What happened to the old 5 pin DIN connector? There was a time when they were popular on amps for tape in and tape out.
Click to expand...
Not such a great construction from a contact reliability and RF perspective, and arguably even more exotic than some of the other options already discussed. If you insist, you can get some nice and solid connectors in the studio space (e.g. Rean NYS 322 G), due to the traditional use for MIDI. It is hard not to prefer a 5-pin XLR.

Since the definitive connector for multichannel balanced connections has yet to establish itself (even DisplayPort has been used before), you pretty much have to go with what makes most sense to you. Even 12x 1/4" TRS would be a fair bit more compact. If it's not too fiddly and you can get ready-made audio cables (studio retailers seem to be stocking several options, e.g. prices at Thomann ranging from about 25@ to 120€ a pop), DB-25 wouldn't be such a bad bet.

For internal wiring of the 25-pin Sub-Ds, a piece of network cable shield provide plenty of twisted pairs for hot and cold. All the Gs are immediately going to chassis ground anyway, so you just need a bundle of wires merged/connected so you can screw it to the case.
 
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