Q: Why does the T-powering on my 302 take so long to start up? Is there something wrong with my mixer?
A: What you are experiencing is normal. There is quite a bit of capacitance in the T-power (sometimes referred to as AB power) circuits in the 302, 442, and MM-1. From a "cold start" you can expect it to take up to 10 seconds for the T-power supply to stabilize. There is no way to speed up the time required to charge these capacitors. Powering the unit, its circuitry, and the T supply from a few penlight batteries requires capacitance for a well-isolated and stable T supply. We fully meet the T-powering specification. Electrically, T-power is inferior to phantom (thus no modern microphone is produced with T-power) and is parts intensive to implement into a preamp.
T-power nearly didn't make the feature list of the 302 and 442 and has been completely phased out of our more current products. The number of present-day audio mixers that provide T-power is less than 10 and they are all portable. We ultimately included it, however. The 442 and MM-1 T supplies behave identically to the 302 (long wait for T power).