Hi all,
I just built a DIY mic with a transound capsule, lifted the schematic from the mp3forkidz website. I'm very happy with the sound that the mic is capturing, but the noise floor is way too high. I notice that when I cut phantom power to the mic it becomes dead quiet and very sensitive until the 220uf filter capacitors drain, so I assume that I would be capable of lowering the S/N ratio of the mic during normal operation if I made the right adjustments.
My experience up until now has been mostly with tube amplifiers, and I don't really know the source of the noise issues, whether it's coming from the source resistors or electrolytic caps, or if there's a property of the transistors that I'm not taking into account. Any suggestions would be welcome!
I was thinking of putting a couple of low value inductors, maybe 10-100uH in series with the mic output, but I thought I'd ask for advice before I went and wasted too much time on anything. I know a good number of people have built this mic, so maybe this is a common problem?
Thank much,
Albert