Have a question about Star Micronics' audio components? Ask our Expert, Jon Levin

Hi Jon:  Thank you for the response to my question.   I'll try to  better define the problem  that I am trying to remedy. All hearing aid (HA) have a basic inherent deficiency  in that they leave the user saying "I hear you but I don't understand what you are saying".  I know the cause of this deficiency and I believe that I have a fix for it. The fix is comparatively straight forward and does not involve such things as amplification or audio frequency shifting. It uses a new  type of modulation, which I choose to name as "serial modulation"            I am far along enough so that I need to demonstrate my fix.  For this I need the output of an A to D Converter, which as I understand is nothing more than a set of numbers  defining the magnitude of the input signal, at some high rate, for examples, 8,000 hertz and at 255 bit resolution.  This I wish to then modify to obtain a better and more  understandable audio output.  The modification would use an EEPROM to accept the input from the AtoD converter and in turn  provide a modified signal output.  The microphone that you described goes part of the way  in that it seems to provide my necessary digital output numbers which then I would modify using the EEPROM  to a new set of numbers for final amplification, then  output to a D to A converter and   to an ear- piece or speaker.       Hope this defines my  problem better  and that you can help out with your insight as to what equipment is needed and is available. Any andall insights are greatly appreciated.    Glad you are a physics major and that because of it hopefully this all makes sense to you. What does the audio processor that you refer to  do?  Is it something like a Digital Signal Processor?

    Thanks, Nate Almond

Nate,  when I mentioned the audio processor I was referring to the audio codecs.  I believe that they often have the ability to encorporate sound processing.  Here is an example from NXP (http://www.nxp.com/#/pip/pip=[pip=UDA1355H]|pp=[t=pip,i=UDA1355H]|).  I would reccomend speaking with them or another chip manufacturer about your application and they can tell you how to add signal processing.

Hi Chris.  My experience is more in acoustics rather that circuitry but I've discussed your question with some of my colleagues.  Can you describe the distortion you are seeing at the high and low limits?  If there are flat edges on the top and bottom of the triangle wave, then the gain of the second op amp is too high. The gain is set by (R1/R2) - See attached circuit diagram.  If you are seeing some other type of distortion there may be some issue with the switching and you may need to talk with the op amp manufacturer to fix the issue.  Using Op-Amps are the only way that we are aware of to create a triangle-wave although a DAC would work as well.  Hopefully this helps.

Sorry this is not an actual reply. I would like to mod my boss DR-5 so that without the use of its midi function I can trigger the sounds by way of keyboard keys. In addition to this I would like to add external speakers and a 16-24 track recorder that will be able to record my performances. Is this possible?

Hi, is the RMS on this actually 350W, or is it an error on the site?    http://uk.farnell.com/jsp/displayProduct.jsp?sku=1149117&CMP=e-2072-00001000&gross_price=true

It just seams too good to be true. 

Alex