SM10A microphone output level with USB Pre

SM10A microphone output level with USB Pre

Date Updated: October 10, 2008 FAQ #1807
Question:
Recently I purchased a Sound Devices USB Pre and a Shure SM10A microphone. The mike worked fine while I was going through my Mackie 1402-VLZ mixer into the line input of a Gateway 9100 laptop. The signal to noise ratio was quite acceptable as the sound floor stayed at about -50. Now with that mike plugged directly into the USB Pre the best sound floor I can get is about -30 and that isn't acceptable in my line of work.The USB Pre works great with a Electrovoice N/D 357B plugged into it for the sound floor stays at about -60. If either of you have recommendations please let me know as a head worn mike is extremely helpful in my recording environments!
Answer:


The output level of the SM10 is 15 dB less than the EV 357B. This is due to the much smaller magnet used in the SM10.
Your options are:
1. Insert a mic preamp between the SM10 and the USB Pre.
2. Ask Sound Devices if the USB Pre can be modified for more gain.
3. Use a step-up transformer like the Shure A96F if the input impedance of the USB Pre is 10,000 ohms or greater.