Sound Blaster Microphone Preamplifier

Circuit is based basically on quite well tested my simple microphone preamplifier. I have built one prototype of this circuit and it worked nicely. Soundblaster soundcard series (SB16, SB32, AWE32 and AWE64) have all a microphone input designed to be used with the electret microphones which come with the soundcard package (some pac
Sound Blaster Microphone Preamplifier - schematic

kages) or with separate microphone designed to be used with SoundBlaster soundcards (there are separate microphones and some monitors have built-in microphones like this). Input Type: Unbalanced Low Impedance Input Sensitivity: Approx. -20dBV (100mV or 0. 1Volt) Input Impedance: 600 to 1500. (Ohms) Input Connector: 3. 5mm Miniplug (Stereo Jack) Input Wiring: Audio on Tip, Ground on Sleeve, 5Volts DC Bias on Ring Because the microphone input needs very high input levels it is not suitable to be used with any other micophone type than elecret capsule microphones. If you connect a dynamic microphone (which gives typically few mV voltage) and try to record it you will get very low signal level with lots of noise. Dynamic microphones can be connected to SoundBlaster if a suitable microphone preamplifier is built which can amplify the signal levels from dynamic microphones so much that they give enough level for SoundBlaster. This amplification can be quite easily done using simple single transistor microphone preamplifier circuit: This circuit gives amplification of about 30-50 which is enough to make the signals from dynamic microphones enough high to be handled well by SoundBlaster. The circuit is very simple so the amplification is not accurately defined (depends on transistor parameters which can vary from transistor to transistor) and other performance figures are not the best possible. The circuit has a very nice feature...

Leave Comment

characters left:

New Circuits