Hi,
I’m in need of some advice about the phantom power.
At this moment I’m still in the process of soldering 3 motherboards (north, center, south) for a test setup to get 3 I/O channels, Group master and a Quad master up and running.
Most PSU’s I worked with the +48V is referenced to the same 0V of the dual supply (+/-18V) that feeds the electronics. In this case the Phantom is isolated and referenced to the +48V Return.
Following the 48V circuit I see only a global on/off in the communication module, there the +48 gets switched and connected to pin 7 of all the I/O channel strips. So now the Mic’s input Hi and LO gets the +48V but the shield is still at OV refernce from the +/-18V, so no Phantom!
So I assume that somewhere in the splice blocks in the desk the +48V return is wired to the 0V of the +/-18V? correct?
Here an overview :
Screenshot 2021-01-29 at 08.54.58 | Phantom Harrison 32 seri… | Flickr
I can send the PSU schematic if needed!
Thanks, I'll need all the help I can get!
Martijn
I’m in need of some advice about the phantom power.
At this moment I’m still in the process of soldering 3 motherboards (north, center, south) for a test setup to get 3 I/O channels, Group master and a Quad master up and running.
Most PSU’s I worked with the +48V is referenced to the same 0V of the dual supply (+/-18V) that feeds the electronics. In this case the Phantom is isolated and referenced to the +48V Return.
Following the 48V circuit I see only a global on/off in the communication module, there the +48 gets switched and connected to pin 7 of all the I/O channel strips. So now the Mic’s input Hi and LO gets the +48V but the shield is still at OV refernce from the +/-18V, so no Phantom!
So I assume that somewhere in the splice blocks in the desk the +48V return is wired to the 0V of the +/-18V? correct?
Here an overview :
Screenshot 2021-01-29 at 08.54.58 | Phantom Harrison 32 seri… | Flickr
I can send the PSU schematic if needed!
Thanks, I'll need all the help I can get!
Martijn