Tag: 302

Q: I experience a loud output noise when the mixer is powered up. It blasts the camera audio levels to maximum. The sound is a low thump combined with a much higher "beep" sound. Why?

The input channel peak LEDs indicate both pre- and post- fade peak levels on the 302. In early production mixers (before 2005) there are two resistors which make channel 2 and channel 3 not indicate post-fade peak levels. This minor condition is fixed on later units. Note that if the channel fader is below unity gain the pre-fade input will always clip first (and be indicated), and if the fader is above unity, the output (as displayed on the meter) will always clip first.

Sound Devices MixPre, 302, and 442 mixers are designed to link directly with each other using a single cable. The Mix In connection on the 302 and 442 is directly compatible with the Mix Out/Tape Out connections on the MixPre, 302, and 442. When linked, one mixer becomes the master and the other the "auxiliary". (more…)

The line-level inputs on the 302 and 442 are attenuated by 40 dB from mic-level and go through the mic transformer. We chose this topology to maintain transformer isolation of line inputs. For our portable field mixers we chose to keep their size small and not have transformers large enough to handle line inputs. The alternative, electronically balancing line inputs along side transformer balanced mic ins, was not practical. The noise penalty is extremely small, since the noise figure of the unit overall is quite low.