I've already posted on two different forums about this and it's just so unusual; I'm hoping someone here can offer a good suggestion for this behavior. I'm not going to re-iterate the whole problem but you can read the account in the first post of this thread over at GS.
In essence I have an AT2022 mic (unbalanced stereo 3-pin out) that works properly with every connection and device I have except a Microtrack II (MT2). When plugged into the 1/8" stereo input, both channels start at equal volume but the left quickly drops in level and then gradually slows down to a level -18 dB lower than the right, and stays there until unplugged.
The curve is reminiscent of what happens sometimes when you measure resistance across a capacitor with a VOM, so my initial suspicion was that something was wrong with the bypass cap in the MT2. However I have a home made stereo mic using 2 ECM capsules wired very simply to a 1/8" stereo jack and there's no DC blocking caps on it: it works without issues on the MT2.
When I inserted 47uF 16v DC blocking caps into the signal path between the AT2022 and the MT2, the levels became balanced and normal.
Possibilities:
1. a deficiency in the left DC blocking cap of the MT2
2. a deficiency on the left DC blocking cap of the AT2022 (must be if it's self powered but I have no schematic...)
3. a problem with the DC supply on the left channel in the MT2 (but the home made ECM mic works fine...)
4. a problem that exhibits only when there is a bias voltage on either side of a DC blocking cap (an AT2022 problem?)
5. a DC blocking cap wired in reverse on the left channel? (I don't think so...)
6. ?
Does any of this ring a bell? Thanks for any suggestions.
In essence I have an AT2022 mic (unbalanced stereo 3-pin out) that works properly with every connection and device I have except a Microtrack II (MT2). When plugged into the 1/8" stereo input, both channels start at equal volume but the left quickly drops in level and then gradually slows down to a level -18 dB lower than the right, and stays there until unplugged.
The curve is reminiscent of what happens sometimes when you measure resistance across a capacitor with a VOM, so my initial suspicion was that something was wrong with the bypass cap in the MT2. However I have a home made stereo mic using 2 ECM capsules wired very simply to a 1/8" stereo jack and there's no DC blocking caps on it: it works without issues on the MT2.
When I inserted 47uF 16v DC blocking caps into the signal path between the AT2022 and the MT2, the levels became balanced and normal.
Possibilities:
1. a deficiency in the left DC blocking cap of the MT2
2. a deficiency on the left DC blocking cap of the AT2022 (must be if it's self powered but I have no schematic...)
3. a problem with the DC supply on the left channel in the MT2 (but the home made ECM mic works fine...)
4. a problem that exhibits only when there is a bias voltage on either side of a DC blocking cap (an AT2022 problem?)
5. a DC blocking cap wired in reverse on the left channel? (I don't think so...)
6. ?
Does any of this ring a bell? Thanks for any suggestions.
