i've found a tidbit here and there on this topic (and used the META META META META), but before i do anything too crazy i want to confirm a few things. bear with me while i think out loud.
MIC LEVEL- when providing a condenser on a 2-way passive mic splitter with phantom power, (this schematic w/ a resistive load across the second isolated out http://www.jensen-transformers.com/datashts/mbd.pdf) please feel free to correct my assumptions:
-only one of the output legs should be supplying 48V
-this shouldn't impact the signal or circuitry at the other leg / require phantom blocking
(example- direct out to FOH w/ 48V off, isolated out to mobile rig supplying 48V).
-shouldn't matter whether the isolated or direct out is supplying the 48V
INSTRUMENT LEVEL- here, i'm planning on modding the jensen 4-way (http://www.jensentransformers.com/as/as014.pdf) to a phantom 2-way. my main assumptions/questions to dispute would be:
-i need to put a blocking cap between the hot nodes of J2 and R1 so phantom power doesn't do anything naughty. i'd be running the 48V from my rig on the isolated out.
-what's the best way (read: quietest signal-wise) to knock the 48V down to the opamp's Vcc here?
-there are probably better opamps to use (read: what's a better opamp to use? ;D)
-then it's just a matter of stripping off outputs 3 & 4 and trimming R7 for a nice output impedance
-if i watned a ground lift, i should make the grounds for the input and the direct out common and put the switch before the grounded node of R1
thanks for sticking it out!
MIC LEVEL- when providing a condenser on a 2-way passive mic splitter with phantom power, (this schematic w/ a resistive load across the second isolated out http://www.jensen-transformers.com/datashts/mbd.pdf) please feel free to correct my assumptions:
-only one of the output legs should be supplying 48V
-this shouldn't impact the signal or circuitry at the other leg / require phantom blocking
(example- direct out to FOH w/ 48V off, isolated out to mobile rig supplying 48V).
-shouldn't matter whether the isolated or direct out is supplying the 48V
INSTRUMENT LEVEL- here, i'm planning on modding the jensen 4-way (http://www.jensentransformers.com/as/as014.pdf) to a phantom 2-way. my main assumptions/questions to dispute would be:
-i need to put a blocking cap between the hot nodes of J2 and R1 so phantom power doesn't do anything naughty. i'd be running the 48V from my rig on the isolated out.
-what's the best way (read: quietest signal-wise) to knock the 48V down to the opamp's Vcc here?
-there are probably better opamps to use (read: what's a better opamp to use? ;D)
-then it's just a matter of stripping off outputs 3 & 4 and trimming R7 for a nice output impedance
-if i watned a ground lift, i should make the grounds for the input and the direct out common and put the switch before the grounded node of R1
thanks for sticking it out!
