QSC Dataport

[Alban Birch]

Hi, I’m building a Multicore to connect between our DCP100 and our Amprack (non-QSC). Where to connect the signal - and + is clear, but I’m stuck with the shields. The multicore has a schield per channel and an overall shield.
Do I connect them on both sides or only on one side?
On the DCP do I use hard ground, data reference ground or to the shell?
On the amps’ XLRs, Pin 1 or shell?

Thanks Guys

[Steve Guttag]

Since the DCP is differential out, strictly speaking, you don't need to tie the reference at both ends. For dataport, the shields go to the shell (chassis). And, since QSC intends that you use their Dataport cables, that would tie the chassis of the amplifier and the DCP processor together. Which, since they are in the same rack, typically, never should cause an issue.

Are you really going to build up HD15 connectors? I've done it/do it but they are not a good place to start since they tend to want smaller conductors and are tightly spaced and have three rows. The biggest conductor in a genuine Dataport cable is 24awg with about half 28awg.

As for the XLR end, it depends on the amplifier and if you need to get it a good signal reference ("balanced" inputs/output designs vary all over the place and some will absolutely flake out if not provided with a good signal reference). And, if you are tying a shield there, if it doesn't have a good earth ground, the shield won't be effective (have to drain the noise somewhere).

May I suggest that you invest in some Odyssey boards? They'll take you from HD15 to terminal block and don't cost that much and will likely save you time in making the HD15s.

https://www.odysseyproducts.com/boards

[Alban Birch]

So shall I use the channel shields as reference on both sides? Pin 10 Data Reference Ground on DCP100 to XLR Pin 1 on Amps?
And I’ll connect the overall shield to the shell?

I’m crimping the pins and that works like a charm as I only have to use four AWG24 wires and the channelshield.

All my amps are fully balanced: Alesis RA150, t.amp E4-130, QSC USA850/900 and PLX1602.

I saw the Odyssey-boards, but I don’t like boards sticking out and it would take a lot of time to get them over the pond.

[Steve Guttag]

Data ground is just that...the reference for the data signals. I'd say it is your choice to connect the grounds at both ends. I would probably just tie the shields at the amp end on pin 1 of the XLR.

[Alban Birch]

Wouldn’t the Data Reference Ground be for the Monitoring Stuff of Dataport Amps?
I’ll try connecting the shield on both sides, connect the amps individually and listen for hum or buzz, if it’s the case for a certain amp, I’ll unpin the Ground of that amp on the processorside
I just measured on the CP100, Pin 6 Hard Ground is the same than Pin 1 of the Mic-XLR and Ground of the AES-Inputs.