I'm using a couple of Schoeps CCM 41V microphones in combination with a Marantz PMD661 deck that has the OAD concert mod.
Most of the time, this combination works flawlessly, but two of the three times I've been out in the field this week, I've run into a strange problem.
Basically, after I rig up, turn the unit on and start to record, the right channel appears to be registering nothing. In actual fact, it's recording a very slight signal, but not enough to make the LEDs flicker.
Removing the batteries and reinserting them didn't help. Nor did unplugging both microphones and plugging them in again.
Eventually, I ran out of time. The support band came on stage and I was forced to go with what I had. My intention was to copy the left channel to the right in post-processing and reluctantly release the recording in mono. Better that than nothing at all.
Now comes the strange part. After about six or seven minutes, I checked my recording levels, expecting to see the same single channel recording being made, but now the right channel was recording at about 50% of the signal that it should have been. Huh? The problem had half fixed itself.
A further seven or eight minutes go by. I look down again. The right channel is now recording at full signal. Huh? Now it's fully fixed itself.
I later record the headlining band with no issues at all.
Back home, I check out the WAV file of the support band and, sure enough, it shows the right channel starting out as almost non-existent and then steadily getting louder until about 16 minutes into the show, by which time the signal has reached full strength.
I'm baffled. What could cause this?
A similar thing happened last night. Upon rigging up, the right channel was registering almost no signal. In an attempt to localise the issue to either the microphones or the recording deck, I swapped the left and right inputs. Both now recorded at full strength, so I switched them back. Pfff. Both were still at full strength, so I was none the wiser.
The support band came on and were recorded without issue, as were the main band later in the evening.
Clearly something is wrong and it's only going to get worse, but what is it? The experience of the microphone starting out with almost no signal and then gradually working up to full strength is the biggest clue, but I have no idea how to interpret it. Once the problem has corrected itself, there are no further issues all evening. if it were a loose connection, I'd expect to see intermittent problems throughout the evening. It's almost as if something needs to warm up before it can properly function.
Have any of you ever seen anything like this before?