Hey Everyone,
Some months (years?) ago I attempted to modify my MXL V77S, V67G, 603S, and 2003. Unfortunately, after modification, all of the mics except the 603S exhibited noise problems. Just tonight I cleaned the PCBs on the V77S, V67G, and MXL 2003, and I think that flux removal may have helped with the noise.
I have a few questions:
The V77S seems to be working properly, sounds clear, and has reasonable self-noise. When I get right on the grill, the noise increases and sounds a bit like the ocean with some lumpiness, then goes away after a few seconds. I'm wondering if this is just moisture from my breath causing condensation on the diaphragm? Is this normal behavior for a condenser mic? If so, then it's probably okay, and I just need to be mindful about technique. This mic is basically stock, except for a new 6072A/12AY7 EH. I think that the new tube might have smoothed the somewhat edgy top end.
The V67G has much less gain, sounds warmer, but muffled, in comparison, and has high self-noise, much higher than the V77S or MXL 2003. With the other two mics, most of the noise I hear is noise in the room. With the V67G, most of the noise is coming from the mic itself. Additionally, the background noise seems to be somewhat variable and "thumpy", especially when reacting to plosives during close-miking. It's been a long time, so I don't remember what this mic was like when it was new. At least two capacitors have been changed, most notably the capsule capacitor, which is now a 0.001 μF polypropylene. As it is, it has low output and is dark and noisy. Any ideas what might be the problem?
The MXL 2003 is a bit of a puzzle. I just cleaned the PCB, reinstalled the diaphragm, and put it back together. It was making a lot of background noise before, especially after plosives, but seems okay now. It does seem to "bottom out" and disappear for a while if you get too close; in this regard, it is more sensitive than my other mics, save the MXL 603S which is extremely sensitive to air pressure. Most reports claim that this microphone is really bright, but I don't find it that bright compared with the V77S. Hard to say which is less colored. Perhaps the V77S is a bit warmer/richer/fuller in the lows, though it still has clarity on top. The 2003 sounds like it has a bit more upper midrange.
Given the low signal levels and high impedances involved, is PCB flux a serious problem with condenser microphones? Is the sensitivity to breath/plosives and resultant "ocean" noise normal for these mics? What about residue on the diaphragm? Something that can/should be cleaned?
Thanks!!!
Some months (years?) ago I attempted to modify my MXL V77S, V67G, 603S, and 2003. Unfortunately, after modification, all of the mics except the 603S exhibited noise problems. Just tonight I cleaned the PCBs on the V77S, V67G, and MXL 2003, and I think that flux removal may have helped with the noise.
I have a few questions:
The V77S seems to be working properly, sounds clear, and has reasonable self-noise. When I get right on the grill, the noise increases and sounds a bit like the ocean with some lumpiness, then goes away after a few seconds. I'm wondering if this is just moisture from my breath causing condensation on the diaphragm? Is this normal behavior for a condenser mic? If so, then it's probably okay, and I just need to be mindful about technique. This mic is basically stock, except for a new 6072A/12AY7 EH. I think that the new tube might have smoothed the somewhat edgy top end.
The V67G has much less gain, sounds warmer, but muffled, in comparison, and has high self-noise, much higher than the V77S or MXL 2003. With the other two mics, most of the noise I hear is noise in the room. With the V67G, most of the noise is coming from the mic itself. Additionally, the background noise seems to be somewhat variable and "thumpy", especially when reacting to plosives during close-miking. It's been a long time, so I don't remember what this mic was like when it was new. At least two capacitors have been changed, most notably the capsule capacitor, which is now a 0.001 μF polypropylene. As it is, it has low output and is dark and noisy. Any ideas what might be the problem?
The MXL 2003 is a bit of a puzzle. I just cleaned the PCB, reinstalled the diaphragm, and put it back together. It was making a lot of background noise before, especially after plosives, but seems okay now. It does seem to "bottom out" and disappear for a while if you get too close; in this regard, it is more sensitive than my other mics, save the MXL 603S which is extremely sensitive to air pressure. Most reports claim that this microphone is really bright, but I don't find it that bright compared with the V77S. Hard to say which is less colored. Perhaps the V77S is a bit warmer/richer/fuller in the lows, though it still has clarity on top. The 2003 sounds like it has a bit more upper midrange.
Given the low signal levels and high impedances involved, is PCB flux a serious problem with condenser microphones? Is the sensitivity to breath/plosives and resultant "ocean" noise normal for these mics? What about residue on the diaphragm? Something that can/should be cleaned?
Thanks!!!
