bahstrike Posted February 3, 2010 Report Share Posted February 3, 2010 hi all,i dont know much about audio circuit design, but i am attempting to make a basic stand-alone digital speaker to be connected to a larger system. the speaker itself needs no indicators or knobs/buttons: only receives audio data and few simple commands (such as volume control). the source for digital audio has not been prescribed, but imagine it may be wireless, ethernet.the logic and signal processing circuitry is intended to run on 5v, but the 20 watt audio amplifier (http://www.st.com/stonline/books/pdf/docs/1469.pdf) is for car applications and its voltage should be 12-14v or so.will I need to stretch the audio circuit's 5v signal up to 12v for this amplifier's input??please help me if obvious errors exist in the schematic (login to view) Quote Link to comment Share on other sites More sharing options...
Alex Tsekenis Posted February 3, 2010 Report Share Posted February 3, 2010 No, you dont need to do that. The 12V of the amplifier is the power supply required, not the minimum input voltage. You are good to go. Quote Link to comment Share on other sites More sharing options...
bahstrike Posted February 3, 2010 Author Report Share Posted February 3, 2010 really? awesome!i am hoping there aren't any critical issues in the whole audio circuit.it will leave me to explore ideas for implementing a "sample pump" for the DAC, probably a simple microcontroller to drive DAC clock lines and fetch samples from a queue in a hunk of external ram (a single 128kb RAM IC should provide a 1.486 second buffer of raw 44100Hz 16-bit audio samples (44100*2 * 1.486)/1024 = 128kb)and another "master" MCU for decoding the digital source and fill RAM with audio samples, to generate logarithmic values into digital pot for volume control, and to act as an identity in the speaker control system Quote Link to comment Share on other sites More sharing options...
Alex Tsekenis Posted February 3, 2010 Report Share Posted February 3, 2010 Consider a microcontroller with a DMA channel. Good luck! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.