You are here

Correct cable wiring for using Inserts as Direct Outs

All about the tools and techniques involved in capturing sound, in the studio or on location.

Correct cable wiring for using Inserts as Direct Outs

Postby traditional85 » Mon Jun 22, 2020 9:27 pm

I am in the process of setting up my home studio and had a question about the correct cable to use for using my Inserts on my mixer for Direct Outs to my recording interface.

I understand you can use the one-click method, but I need something more secure and permanent. I also know Hosa makes their adapters (DOC-106) and sell them for roughly $10 each. Considering I'd need 16+ of these I'd rather not spend $160 on the adapters AND cables. I'm looking for a proper and clean snake setup, so is it possible to simply modify a standard TRS to achieve what I'm looking to do?

Based on the attached image, I would simply solder/bridge the T and R of the cable, and on the other end it shows a male TS with the T and R together, and sleeve/ground unchanged. I'd rather not have to cut off the end and solder on a TS so would I simply be able to just use a standard TRS cable and bridge the T and R on both ends? Am I overthinking something, is it this simple or am I way off?

Image
traditional85
New here
Posts: 7
Joined: Mon Jun 22, 2020 9:25 pm

Re: Correct cable wiring for using Inserts as Direct Outs

Postby Hugh Robjohns » Mon Jun 22, 2020 10:31 pm

I'm afraid your idea won't work if your interface has balanced inputs -- and most do!

Obviously, the insert end needs to have the tip and ring shorted together to maintain the signal path through the console.But if you leave the TRS plug with either standard wiring at the interface end, or with bridged tip and ring terminals, the differential (balanced) input in the interface will see the same signal on the hot and cold input contacts, and with no difference that means no signal to record.

Personally, I'd buy 8 long TRS-TRS cables (with moulded plugs to save money) and 16 TS plugs. Cut the long balanced TRS cables in half, and solder the replacement TS plugs on as per your diagram, wiring the tip and ring signal wires in the TRS cables both to the TS plug tip contact. Screen to sleeve. With this arrangement it's quite obvious what the function of the cable is and, more importantly, which end of the cable needs to go into which device!

Alternatively, you could modify both ends of ready-made TRS-TRS cables, provided they have plugs which can be disassembled. At the insert end, bridge the tip and ring contacts, and snip/isolate the ring wire in the cable. At the interface end, snip/isolate the ring wire again and bridge the sleeve and ring contacts. You'll need to mark which end of the cable is which, though, because if you plug the cable in the wrong way around you'll kill the signal through the mixer and record nothing at all!

There is also a third wiring option which would avoid the potential of ground-loop problems between mixer and interface. At the insert end, unsolder the ring wire and resolder it onto the sleeve terminal along with the screen. Then link the tip and ring terminals as before. At the interface end, leave the tip and ring signal wires alone, but snip and isolate the screen connection to the sleeve.

I'll add some diagrams to this post tomorrow when I'm back at my desk computer.
User avatar
Hugh Robjohns
Moderator
Posts: 27604
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Re: Correct cable wiring for using Inserts as Direct Outs

Postby Sam Spoons » Mon Jun 22, 2020 10:35 pm

That diagram is misleading as a TRS insert will not have hot and cold but send and return. But it should work if you have TS at the MTR end. If you plan to use TRS at the MTR end they will need wiring with the R+S connections bridged and the T only connected to the signal wire.

Image

edit, this, I think is Hugh's second option, I'll leave him to draw the third option later.
User avatar
Sam Spoons
Jedi Poster
Posts: 12776
Joined: Thu Jan 23, 2003 1:00 am
Location: Manchester UK
Finally taking this recording lark seriously (and recording my Gypsy Jazz CD)........

Re: Correct cable wiring for using Inserts as Direct Outs

Postby traditional85 » Tue Jun 23, 2020 12:35 am

Thanks so much for the replies, guys!

That diagram was just an example of what I would need to do, disregarding the TS plug on the end.

I've been talking with several others and they pretty much said the same as you, I think? Mind you, cabling/balanced/unbalanced setups aren't like a first language to me so forgive me if I am not understanding everything right away.

The setup is simply a Behringer SX3242FX and the interface is a Behringer UMC1820. Not expensive by any means, it's just temporary satellite setup in a spare bedroom.

My first option from someone else (in regards to the diagram) was to bridge the T and R on the insert end and move the R on the recorder end to T, leaving the R terminal unconnected.

The second option would be to use 1/4" TRS male to TS female adapter from the Inserts, then a TS cable to the interface. Would that matter in regards to the interface accepting balanced line inputs?

What would you guys do if it were you? My only requirement is to not use the first-click method. I don't mind soldering but I'd prefer to not have to chop off ends and replace them with another type if using an adapter or simply doing the quick solder would work the same way.

If I were to buy a 16 channel TRS snake with serviceable ends, what modifications would I need to perform to get it working?

Thanks again.
traditional85
New here
Posts: 7
Joined: Mon Jun 22, 2020 9:25 pm

Re: Correct cable wiring for using Inserts as Direct Outs

Postby Hugh Robjohns » Tue Jun 23, 2020 1:25 am

traditional85 wrote:My first option from someone else (in regards to the diagram) was to bridge the T and R on the insert end and move the R on the recorder end to T, leaving the R terminal unconnected.

It's not really a good idea to leave the ring disconnected at the interface end. Better to bridge it to the screen connection. And there's no point bridging T and R at the insert end when you are already joing them together at the interface end by moving the ring wire to the tip anyway. Why mess with the innards of two plugs when you can do everything necessary in just one?
User avatar
Hugh Robjohns
Moderator
Posts: 27604
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Re: Correct cable wiring for using Inserts as Direct Outs

Postby Mike Stranks » Tue Jun 23, 2020 7:52 am

I've done this a couple of times... simply bought a TRS-TRS loom, chopped off one set of TRS plugs and replaced them with TS... worked fine.
Mike Stranks
Jedi Poster
Posts: 7332
Joined: Fri Jan 03, 2003 1:00 am

Re: Correct cable wiring for using Inserts as Direct Outs

Postby Sam Spoons » Tue Jun 23, 2020 11:19 am

I would expect the UMC1820 to have balanced TRS Line inputs but the quick start guide (there doesn't appear to be a full manual on the website) doesn't confirm. Then there is the possibility of phantom appearing on the TRS jacks.

I'm with t'others, much quicker to buy a long cable, chop it in half and solder some TS jacks on the MTR end.
User avatar
Sam Spoons
Jedi Poster
Posts: 12776
Joined: Thu Jan 23, 2003 1:00 am
Location: Manchester UK
Finally taking this recording lark seriously (and recording my Gypsy Jazz CD)........

Re: Correct cable wiring for using Inserts as Direct Outs

Postby Hugh Robjohns » Tue Jun 23, 2020 12:03 pm

Diagrams as promised:
Insert to interface wiring.png


The top image shows the standard way of doing it, lopping off a TRS connector and soldering on a TS one instead. Quick and easy to do, and it's obvious which way around to plug the cable!

The middle image (Option 2) uses a TRS-TRS cable, but the wiring in both plugs needs modification, and the cable ends need to be labelled to make sure it is used the right way around. It involves lots of work -- far more than fitting a TS plug -- and offers no practical benefits.

The bottom image (Option 3) also uses a TRS-TRS cable and also requires modifications to both plugs*, but it does have the benefit of separating the ground references of the mixer insert and interface input, relying instead on the differential nature of the balanced input to capture the wanted signal without tying the grounds together, thereby avoiding any risk of a ground-loop hum. Again, the cable will only work one way around so the ends need to be labelled.

* If you're feeling really lazy, you could leave the interface balanced input end of the cable intact, and only modify the insert end, cutting the screen connection at the source, rather than the destination. This is technically sub-optimal, but will usually work without problem and does cut down on the cable modifications work!
User avatar
Hugh Robjohns
Moderator
Posts: 27604
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Re: Correct cable wiring for using Inserts as Direct Outs

Postby traditional85 » Tue Jun 23, 2020 11:28 pm

Thanks for all of the replies and explanations, and specifically the diagrams!

I'll give it all some thought and mull it over.

Quick few questions and then I'll head out... if doing option 1, instead of chopping off the TRS and soldering on a TS, would adding a 1/4" TRS to TS adapter instead do the same thing?

I am a little confused, however, because on a review of a 1/4" TS Female to 1/4" TRS Male Adapter, the reviewer said: "I was looking for an adapter to use the insert's on my mixer channel strips as direct outs....This adapter works as direct out's!!!"

In what configuration would this have worked? Adapter into the Inserts -> TS cable -> Interface? If so, would this be all I need to do?
traditional85
New here
Posts: 7
Joined: Mon Jun 22, 2020 9:25 pm

Re: Correct cable wiring for using Inserts as Direct Outs

Postby Hugh Robjohns » Wed Jun 24, 2020 10:11 am

traditional85 wrote:Quick few questions and then I'll head out... if doing option 1, instead of chopping off the TRS and soldering on a TS, would adding a 1/4" TRS to TS adapter instead do the same thing?

You're really keen not to break out the soldering iron, aren't you? :lol: The answer is, most TRS to TS in-line adaptors short the tip and ring contacts together, replicating option 1.

However, I really wouldn't recommend going down that route for two reasons:
1) adaptors are notoriously unreliable, and -- much more importantly...
2) using adaptor plugs in equipment sockets vastly increases the leverage acting on the internal contact springs and that risks bending or breaking them, further increasing the chances of unreliability over time.
...and 3)... because quarter-inch plugs are so physically long, using adaptors makes the combined plug stick out so far from the socket that it's just ugly and inconvenient too...

In what configuration would this have worked? Adapter into the Inserts -> TS cable -> Interface? If so, would this be all I need to do?

There are two kinds of TRS-TS adaptor. If it's a TRS socket to TS plug then you'd need to use it at the interface end, and you must use a TRS-TRS cable with it. (If used at the mixer insert end it would mute the return signal path through the mixer channel).

If it's a TS socket to TRS plug you'd use that at the mixer Insert end, and you could use either a TS-TS or TRS-TRS cable...

...But I still wouldn't recommend using adaptors!

Be brave. Break out the soldering iron, some side-cutters and the wire strippers and spend a happy hour or so making your own solid, reliable, custom-built cables!
User avatar
Hugh Robjohns
Moderator
Posts: 27604
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Re: Correct cable wiring for using Inserts as Direct Outs

Postby traditional85 » Fri Jun 26, 2020 12:41 am

I've no issues with taking out the soldering iron, haha! It's always on my work bench for when I do custom motorcycle wiring work anyway. But if I could just buy something and have it work just as well (minus using adapters!) and cost less, why not?

Seismic Audio sells a TRS->TS snake. Would this work just fine? It's cheaper than buying TRS cables plus the TS plugs.

Sorry for dragging such a simple matter on for so long.
traditional85
New here
Posts: 7
Joined: Mon Jun 22, 2020 9:25 pm

Re: Correct cable wiring for using Inserts as Direct Outs

Postby Hugh Robjohns » Fri Jun 26, 2020 9:58 am

traditional85 wrote:Seismic Audio sells a TRS->TS snake. Would this work just fine? It's cheaper than buying TRS cables plus the TS plugs.

I think the short answer is NO... but just in case, do you have a link?

Rummaging the Seismic site I've found several Insert break-out cables and snakes, but they are TRS to dual TS -- one TS plug for the send side and one for the return. They are intended for bringing console insert points out onto patch bays or for patching in effects units etc.

eg:

https://www.seismicaudiospeakers.com/products/8-channel-xlr-to-trs-10-feet

Consequently, they don't link the tip and ring contacts in the TRS plug to maintain the signal path through the console as you would require, and you'd be paying for twice as much cable and twice as many TS plugs as you actually need, too!

I'm afraid I cant recall ever seeing proper recording 'sniffer' cables -- which is what you need -- available as a commercial product.

That's probably why we all found it quicker and easier (and more reliable) just to buy double-length TRS-TRS cables, a bag of TS plugs, and spend an hour cutting, stripping and soldering them up.
User avatar
Hugh Robjohns
Moderator
Posts: 27604
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Re: Correct cable wiring for using Inserts as Direct Outs

Postby Hugh Robjohns » Fri Jun 26, 2020 12:32 pm

Hugh Robjohns wrote:I'm afraid I cant recall ever seeing proper recording 'sniffer' cables -- which is what you need -- available as a commercial product.

I have been advised by one of the Mike twins that there is such a thing, commercially available... pretty pricey though!

https://www.thomann.de/gb/pro_snake_jam_cable_3m.htm

Image
User avatar
Hugh Robjohns
Moderator
Posts: 27604
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Re: Correct cable wiring for using Inserts as Direct Outs

Postby traditional85 » Fri Jun 26, 2020 11:21 pm

That was the snake I was referring to. But, upon a closer inspection I just now did notice that it was a true insert cable and not a straight 16 TRS to 16 TS. I thought it was a 16->16 not an 8->16. My bad, it was a late night!

Looks like I'll just go the soldering route, grab 8 long TRS cables, chop them and then add TS to the ends. For kicks, I'll also grab a 16 channel TRS snake (for other applications) and some TS adapters for the interface end and just give it a shot to see how reliable they can be. Adapters aren't the devil as most people seem to think they are, and they're cheap enough to have some laying around if needed.
traditional85
New here
Posts: 7
Joined: Mon Jun 22, 2020 9:25 pm

Re: Correct cable wiring for using Inserts as Direct Outs

Postby Sam Spoons » Sat Jun 27, 2020 9:47 am

traditional85 wrote:Looks like I'll just go the soldering route, grab 8 long TRS cables, chop them and then add TS to the ends.

Makes sense :thumbup:

For kicks, I'll also grab a 16 channel TRS snake (for other applications) and some TS adapters for the interface end and just give it a shot to see how reliable they can be. Adapters aren't the devil as most people seem to think they are, and they're cheap enough to have some laying around if needed.

The biggest problem with 'adapters' (as opposed to 'adapter leads)' is the extra leverage making physical damage to chassis sockets much more likely.
User avatar
Sam Spoons
Jedi Poster
Posts: 12776
Joined: Thu Jan 23, 2003 1:00 am
Location: Manchester UK
Finally taking this recording lark seriously (and recording my Gypsy Jazz CD)........

Next