So today I powered up the 2203 ,
Theres signal comming through alright but also very strong low frequency noise .
Even though I have the documentation I still cant find the schematic.
What I do know is ,
the capsule has a polarising voltage of 200v ,
the input stage uses a type 2N3457 fet ,
the noise remains even with the capsule removed however the carachter of the sound does change when the capsule is in place , this seems to be due to the loading effect of the capsule .
Output stage is working fine and the metering is also accurate .
The unwanted sound Im hearing is a bit like what a bad electrolytic would make when the electrolyte is reforming, so heavy low frequency disturbances as well as higher frequency sizzling type sounds . Maybe the best thing is powering up for an extended period of time to see if the situation changes or resolves itself .
Any ideas appreciated .
Theres signal comming through alright but also very strong low frequency noise .
Even though I have the documentation I still cant find the schematic.
What I do know is ,
the capsule has a polarising voltage of 200v ,
the input stage uses a type 2N3457 fet ,
the noise remains even with the capsule removed however the carachter of the sound does change when the capsule is in place , this seems to be due to the loading effect of the capsule .
Output stage is working fine and the metering is also accurate .
The unwanted sound Im hearing is a bit like what a bad electrolytic would make when the electrolyte is reforming, so heavy low frequency disturbances as well as higher frequency sizzling type sounds . Maybe the best thing is powering up for an extended period of time to see if the situation changes or resolves itself .
Any ideas appreciated .
