Hi all!
just to give you a little background:
I already modded my paradisea dac with a OPA sun instead the LM4562 op-amp in the output stage, It worked great, that great in fact that i wanted to mod my constantine as well.
so i desoldered the original AD op-amp from the bottom of the pcb and soldered wires to the left space and a socket onto the other end.
here are some images to explain it better:
please note that i traced the connections from the op-amp to larger spots. that made the soldering easier. I once did the X-fi op-amp mod but i took the easy way this time.
now here comes my problem:
when i connect the OPA module (regardless if earth or moon) i have a very annoying 60Hz hum in the speakers. interesting thing is when i connect one of the op-amps (LM4562) i have to the "extension lead" the hum is gone. it only exists while OPA is connected. i tested the OPAs in my zero and they work fine.
one thing i noticed is that when i connect the ground wire from the OPA to ground in the constantine the signal gets a lot weaker and distorted.
That doesn't happen with the zero nor the paradisea.
I thought since paradisea and constantine are similar dac's the mod should be pretty easy.
do you guys have some suggestions for me ? any help would be appreciated.
just to give you a little background:
I already modded my paradisea dac with a OPA sun instead the LM4562 op-amp in the output stage, It worked great, that great in fact that i wanted to mod my constantine as well.
so i desoldered the original AD op-amp from the bottom of the pcb and soldered wires to the left space and a socket onto the other end.
here are some images to explain it better:
please note that i traced the connections from the op-amp to larger spots. that made the soldering easier. I once did the X-fi op-amp mod but i took the easy way this time.
now here comes my problem:
when i connect the OPA module (regardless if earth or moon) i have a very annoying 60Hz hum in the speakers. interesting thing is when i connect one of the op-amps (LM4562) i have to the "extension lead" the hum is gone. it only exists while OPA is connected. i tested the OPAs in my zero and they work fine.
one thing i noticed is that when i connect the ground wire from the OPA to ground in the constantine the signal gets a lot weaker and distorted.
That doesn't happen with the zero nor the paradisea.
I thought since paradisea and constantine are similar dac's the mod should be pretty easy.
do you guys have some suggestions for me ? any help would be appreciated.
