T15 Phantom Power

[kentsheehey]

I just built two T15s and they both work great accept for the fact that one of them takes around 8 seconds for the phantom power to activate. During the activation there is a second of distorted signal at around the 5 second mark.
What could be the problem?

[tpryan]

The rise and fall time of phantom power is set by R37 and C26. It should take about 3 seconds to get 90% of the way to +48V, so if it's taking 8 seconds you may have some bad soldering or misplaced components. In any case, there's no telling what the mic's output amplifier will do during the transition, which is why you should always mute the channel or your monitors when switching phantom on or off.