Adding phantom power to Calrec PQ 1161 issues?

[mkiijam]

Hello, I'm considering adding phantom power to my pair of 1161 pre and am looking for some guidance. Should I use DC blocking caps before the transformer? any other concerns?

 

[Brian Roth]

With a typical preamp using an input transformer, no need for blocking caps.

Some (typical ancient) circuits have a grounded center tap on the input xfmr and those require special consideration.

Phantom must be inserted prior to any input pads, either internal or external to the module. If the modules are racked, adding the required pair of 6k8 resistors directly to the input XLRs is an easy solution.

Check the schematic of the module to see if there is any "funny business" connected to the primary of the mic xfmr. Someone familiar with those modules might add some additional suggestions.

Bri

 

[gyraf]

Calrec had phantom power external to the mic amps, switched in at the incoming miclines to the patchbay.
Two 6k8 resistors to + and - lines.

Dosent get easier than that