Insert Direct Out Cable

[bassburner]

My cover band uses the Hear Technologies in-ear system. This consists of a DB25 to 1/4" snake cable. To get it to work the 1/4" TRS plugs need to be half pushed into the mixer inserts. As we recently found, it's easy for one of these to wiggle a little in or out causing the case in which the signal is interrupted and not coming out of the mains but still coming through the in-ears.

Anyway, Hear and Hosa both sell cables to combat this problem:

[Invalid or Expired Link Removed]
Instead of buying 8 $12 cables I got the jacks and cable to make themselves. However, this doesn't seem to work. Everything checks out according to that diagram with a multimeter. I'm guessing because the ground isn't hooked up on the male side.

Is this schematic missing something?

 

[line6man]

There should not be any connection to the tip terminal on the "console insert" side.

 

[bassburner]

There should not be any connection to the tip terminal on the "console insert" side.

But the output ring should still go to the console shield?

Now that I'm not tired I would think it should be wired up like a normal cable but you short between the tip and ring on the console side.

 

[line6man]

But the output ring should still go to the console shield?

Now that I'm not tired I would think it should be wired up like a normal cable but you short between the tip and ring on the console side.

As I understand, you have been plugging a connector halfway into a jack, but you want an adapter that allows you to have a connector plugged all the way in. If this is correct, then you should have nothing connected to the tip terminal, as that terminal has nothing connected to it when a connector is halfway in.

 

[RobbieK]

An insert is a patch-point between the preamp and the rest of the channel strip on your desk. It's very similar to an effects loop on an amp, but the send and return are on the same jack. If memory serves, the send is from the tip and the return is on the ring. Like Line6, I can't see the point of having the send and return shorted like that. The low z desk mic pre output would load the insert return. Maybe I'm missing something, though. Perhaps that is a misprint, and the tip of the male plug should be connected to the sleeve/desk earth instead. This would harmlessly mute the output of the desk mic pre (AKA the insert send).

You could probably run the tip of the female jack to the ring of the male jack and connect the cable shield to the sleeves at both ends. This would be fine if your device is not wireless, but battery powered, but you will lose a little signal just running the unbalanced signal from a balanced output. If the devices are wireless, and the balanced out is coming from a mains powered receiver, then you run the risk of earth loop hum, plus of course induced hum as neither the insert send or return are balanced.

 

[LUpton]

The reason for the shorting of the tip and ring on the insert cable is to re-create the 'normally-closed' connections that exist on the console insert jack when no cable is plugged into it. That is the signal path for the mic pre output to get to the rest of the channel strip circuitry - EQ, sends, etc. The desired action with this cable is to tap off of this signal, not interrupt it, hence the red wire connected to the console-side T/R, then to the tip of the female jack. All that is desired is a pre-fade send, essentially.

Mackie used to trumpet this 'feature' in their owners manuals, specifically telling the user that a 1/4" TS connector (a guitar cable, essentially) inserted into the insert jack until the first click would 'tap' the mic pre signal without interrupting the normalled connection, by virtue of the fact that the Mackie insert jacks were wired ring=send, tip=return, and not plugging all the way into the jack would not activate the switching contacts on the jack which interrupt the signal flow.

The 'plug it halfway in' thing is a potentially flaky approach, as the OP has found out, but if there is not a pre-fade send available on their console, there is no reason that the above-mentioned adapter cable wouldn't work to fix the problem. I personally wouldn't approach things this way, but YMMV...

 

[RobbieK]

Ahh. Fair enough, that makes sense. I just assumed that the device was feeding in to the desk, but yeah if you need essentially another set of prefader aux sends, then that cable diagram looks right to me...