This is a multi-part message in MIME format. ------=_NextPart_000_1232_01C6AA67.DB370F90 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit > Hmm. The circuit you show is hardly complete Attached is complete bug circuit (9V battery). I've built several for voice and line input, work fine > So can you tell us what the output impedence of a properly > biased electret is, and what a typical output voltage level is for > normal voice input? Mark Rages beat me to it. Electret "inserts" have an internal FET > Assuming its RMS and we want 5V peak-to-peak, the desired > gain would be about 2000 The OP said "voice recording project", so somewhat less than clipping would be desirable ------=_NextPart_000_1232_01C6AA67.DB370F90 Content-Type: image/gif; name="FMbug.gif" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="FMbug.gif" R0lGODlhPgGbAIAAAAAAAP///ywAAAAAPgGbAEAC/oyPqcvtD6OctNqLs968+w+G4kiWpgQsqbKC 7QkHb/zMNGbTOQvMO3to/TrDm6cY6ymXQWFQ9jRCOU5DFSnCEqUmrY47jVrDCe9WatakjVVoygdu rONk9pweGcJX9y7+31cHE/gHQaj25KRomCf2ligW0vY41na0hJmpuZnp8EJZhsAko1R4WBg58Yl6 EYh0msr6ASt3Qzvr4le7O6Yqi6viGAZqc1vz28vDJ2jpCbmcHOsrzYuMyEjNYNzDPGrF/Q2eXEp1 pNsoKgr9nW2Ngx6NPQvq3m5hbE/1s5ozOWx6Ap8KcrIEAgnHZ93BaZDiyRFXr0yxfvggyhPk6ZS/ /kUOs5CYs+pdRGUZDhnUJtJjSYat8Jg5iYIey5XVCJJ7oyclSlIEnVXo+WrnsVBNFArj+C/PJnXp 4uzb2HBhEqJT+n28ly/fPqdYu345N7XlCJBexXKdOTKt2rVs27p9CzcuXE5069q9izev3r18+/r9 Czjw0nGEq9UxCBPNr8S56DB+9FhuMLVQK2Vt2rAZjlE+LHYc+9WaOKSYUTE+czb0IMlUXXZKe3oy a6Hx+LnD8mm054+VMbYum0VmUXCYItnczSU27aRufH+ejeKaz1bCoS9XyWiP0jUhL9FCfJFIT+vO zalmVXF6L2LPJdJVp5d86dLH1xVbXW/HzUre/uZvuKMdclLJlxd8ggFGW3WZDVcOMNjxVtNhzLEH SED43dbYg7xQ+NBlkiWmXHkxHZXVLfrBx596NAEHm1HhrRidh+zYMtRPLFJAloy/1eiUgC/eKIxl KToH4FU6lecKQPD0uGOT0oVFIo7R+DOglA0y59B9pCzEnmYiLhlVZBuG2ZyTRgJ5JY8eJumYlfK9 CWeccs5JZ5123onnnX3lyWefZsl04o4ChWhhQW0RKiNpCfrnIHSIqjjSo1+e4aIkBC526H/GFdae JD42OpukNhKGlBb1faYRfZvSCKWjmMrGU1GcgpkQrGzc2qp1opopWmq5lrBrjYt4WSFbkn6a/mGh GMpaVZW2vBfRsXN2JgRxyxaE7DwIJifnVk1lC0awLj0ZnI5yiWteLb3hBO6fZBILY7kRakequZYq +S6S8JSKZbKnJsUJmvbOuKhV9Xb6qw5MFBdrs9fxySakqsB7aZv0Tswdo3r++F+7mYKlrJuTipxm sg+jVjGwrL6abkZGjRdUhGi5ykOUXyqHbpOkNROzG1QizONLcQb6D7+8moyebJAxCl5M1faRM9L3 zjPwyihLraJ9ar6Jm8Ynl0R0mf5RQnGMLWMNJDcU3eRNbk+btqTQLoSttSVaa6rtgXrvNS+snI0X bsjiVX0e3hqWGzXIh/OW+MhqdDezNrnN/tjz0IJfXuzjmjDdr9fuMYuT042XvLh6aaR6sM9AGx75 0Yse2aLnhNfM0kuohwP6lsMxvB3fYO+5+96DOabg1mYlkWPpNZxOrtmOO2tYch67zrHuRa8J+9kk G996wtGjUbzE2U94facZgwajgib5Wr3C2JPevKBlq0tUf7Ivv5IikAsZikJtW1ubdP1tddThHfpC s7PhYaY7BrvHKxRYrY5Azjafw50F7+c1tw0Jc0ES29JmN6rxwU9d0ytS5sB0Lb/pBhpwsNr2tNc9 6DmPWzGEG7Cm9zsHVqSEHgOc03pkKhz6aYhELKIRj4jEJCpxiUxsohOfCMUoSnGKVHQh/jVGV8Us uiyAzmqgFr8YrSjAS0sYFJhbfBguIUoPUWg0UFSW00LlzYVllGGf0jA4QZWRJ3FY/BoHMzS/+J2L jrBpU6EqhbY5GspY+kgI28joh/DBcJCLlMq/cJWmuz2vkd6LSx/JxD92iYl1PyNUbD5pxqSljkPT 6ZKtjsRA6k1Sjm8RV8A66EoCBhBQ4yrcmWimShrarIyJPOAfPVnJZ5WiOC5io2I6ia+Ghe2EkTKk L41pqMoEEpOFtKPifomMjcQxmHVMo/Dsck0bXg+S1Kxm4CyXMjBKa1rABKP1ngmnOOayV0aEmjPh aZgPhrOfggQnQOejKHIyklkN494M/j2ly1Dtjidqiyg0CWa0SNpMlMFr4/e01TeJbDSa4HubBSs3 plB2ToD5sij+IPSQhQFlpNakZi69JayWbpIh/NrmxLZIHdNhxIs7peWF1pOIInSNoftxKTdT6c+n NLU1l+zlO1fVnJwUMWIfVYpTaxnP2lFShCAsqztraq/kFRWICkShDEWCSrKK55bkQ8g5IXLXuyrD fg9962biejxsSswLat0G1jzqULP6FZnfNGjcpna1YjaNa8eErEJZZ9m37i+xY3WsZ606y9TVNbGb 7VA+E7RCt34WrblDkV85Mwy8ZvKnp+3fSPm61sCqc4EOw2ory8SzJ8mNsndUqWZw/sZPqoTuN0Fk 4QUVG8Kw4rJ8zLgoa9eZjfSYjZUvlGhjQTXQYuqWVrpDqXQz27GvWjFe4kVoB19J3KB1N4eWLMxE ZiXX+Y5wr6KETGfUa6zKEVaNkpPcwva6IADnFr6RHR8aKciUVZpCwBibW8GcYcAFKzjCc4OJgDrR n3WR9HV91dxAgJLaBRKYmF71lIdxKjbOsXi1DX7chisb3faa+MQApGqK24leHXuTvaF1bUNNC9j9 Ftk8jTMJBN1Y4oCqjrPe1eMgVixYSwXXR8xLRyAR+SEcCzmdUuMuHt8F5gqed8xKrt2PqdxdcT7n djmuZ5aFqt9GiHi5dsVtndsH/t1UBjjD4JVvnrer01EG2dDjjdY4Gfy7+HQUnVfqaZrnOpbzORWx i/Hpd6Lb5fXO2KKu0PRaOR1oBxaVzo/F0V9o7MdYw7m++R01RNVKZCv/ucaqlbX4yLzYgBB4fTV5 M6C7itldQ7rX1rV1h3MdZ/INS6uCbjRQa/hrYDsbpLWu3p7bgetCzwTG1m72jcG26lnuOc3hXrLM kM3sH14QZsp22zYuHexj15CME9mcSMsItTkPD1n3FW0qMqphlXrZyWd2d6MoxLxYSrCgPPUffAUq 4eM22Mw/Kfi/F23MCHZ8qivlDqrloXH38i/jsVBqW+Wc8PZp8KTwhmxCzYdVdKLGiLBC4bPKKUo2 Xvs635Pk0E23Xe5ZV/u9x54mPqOcTC6hmehCV7qyBzTcpcMa6WT+NjvFvGyK61u9u8p6fsDucKof eiBXH/vWU23UZH/X6mtX+4KxLHZZuiavfO+73/8O+MCf056EL7zhD4/4xCteFgUAADs= ------=_NextPart_000_1232_01C6AA67.DB370F90 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist ------=_NextPart_000_1232_01C6AA67.DB370F90--