Conviction
Well-known member
Hi all,
I recently picked up an AKG C414-E1 complete with the pattern remote control. It's in great condition, barely used.
Out of curiosity, I checked the polarization voltages and discovered that the node for the backplate (negative/positive, -60/0/+60) was extremely low - and I can't really tell any difference between the patterns.
In figure-8, my voltmeter is showing a maximum of -16.5VDC.
The output voltage from the selector switch(es) corresponds with those stated in the schematic. Nothing wrong there.
However, after R6 & R7, the 27M resistors decoupled with 22nF(see schematic and parts list), the voltage drops down to -16.5VDC.
Is this due to loading? I thought a VTVM would take care of that.
First I used my Fluke DMM, then an old Simpson 260 VTVM.
Please excuse my ignorance :-X
I recently picked up an AKG C414-E1 complete with the pattern remote control. It's in great condition, barely used.
Out of curiosity, I checked the polarization voltages and discovered that the node for the backplate (negative/positive, -60/0/+60) was extremely low - and I can't really tell any difference between the patterns.
In figure-8, my voltmeter is showing a maximum of -16.5VDC.
The output voltage from the selector switch(es) corresponds with those stated in the schematic. Nothing wrong there.
However, after R6 & R7, the 27M resistors decoupled with 22nF(see schematic and parts list), the voltage drops down to -16.5VDC.
Is this due to loading? I thought a VTVM would take care of that.
First I used my Fluke DMM, then an old Simpson 260 VTVM.
Please excuse my ignorance :-X