Subject: Preamplifier for Knowles Microphones From: =?EUC-KR?B?sei787jt?= <smkim123@xxxxxxxx> Date: Fri, 26 May 2006 23:50:57 +0900This is a multi-part message in MIME format... ------------=_1148656249-22460-86 Content-Type: text/html; charset=euc-kr Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Dear,<br> I plan to measure the microphone sensitivity of a Knowles TM series microph= one that is <br> typically installed in hearing aids.<br> My problem is that the microphone output response is extremely low (0.18mV = to 73 dB SPL)<br> so that I feel that I have to use a high gain pre-amplifier possiblly as mu= ch as about 60 dB.<br> Does anyone know any good commercial preamplifer for this purpose or any al= ternative way?<br> Thank you in advance for your suggestions.<br> <br> Sang<br> -Hearing instrument engineer <!-- __Hanmail-sig-Start__ --> <br>=20 <!-- __Hanmail-sig-End__ --> =20 <!-- __Hanmail-tail-Start__ --> <!--=C7=B2=C5=CD =B5=F0=C6=FA=C6=AE--> <table border=3D"0" width=3D"100%" cellpadding=3D"0" cellspacing=3D"0" alig= n=3D"center"> <tr><td height=3D"5"></td></tr> <tr><td colspan=3D"3" height=3D"1" background=3D"http://mailimg.hanmail.net= /05mail/img_dotline.gif"></td></tr> <tr> <td colspan=3D"3" height=3D"32" class=3D"d_12_333333" style=3D"padding-top:= 4px;">"=BF=EC=B8=AE =C0=CE=C5=CD=B3=DD, Daum" <a href=3D"http://www.daum.ne= t" target=3D"_top" class=3D"d_12_333333">http://www.daum.net</a> =A1=BA=C6= =F2=BB=FD=BE=B2=B4=C2 =B9=AB=B7=E1 =C7=D1=B8=DE=C0=CF=B3=DD=A1=BB<br></td> </tr> <tr> <td width=3D"50%" style=3D"border:1px #dfdfdf solid;"> <a href=3D"http://da= umdirect.daum.net/websales/main/event/20051229_hana.jsp?_partner_code.key= =3D9100009" target=3D"_new"><img src=3D"http://mailimg.hanmail.net/05img/b= anner/footbn_060203_daumdirect.gif" width=3D"350" height=3D"48" border=3D"0= "></a><br></td> <td width=3D"12" nowrap></td> <td width=3D"50%" style=3D"border:1px #dfdfdf solid;"><a href=3D"http://allim.daum.net/servlet/Redirect?sid=3Dfooter_multikit0522" target=3D"new"> <img src=3D"http://image.hanmail.net/hanmail/s_img/multikit/pm/footbn_06051= 9.jpg" width=3D"350" height=3D"48" border=3D"0"></a><br></td>=20=20=20=20=20=20=20= =20=20=20=20=20=20 </tr> </table> <!-- __Hanmail-tail-End__ --> <img src=3D"http://wwl37.hanmail.net:4280/@xxxxxxxx=3Dsmkim123&rcpt=3DAUDITORY%= 40LISTS%2EMCGILL%2ECA&msgid=3D%3C20060526235057%2EHM%2EB000000000FpbWF%40sm= kim123%2Ewwl37%2Ehanmail%2Enet%3E"> ------------=_1148656249-22460-86 Content-Type: text/plain; name="SpamAssassinReport.txt" Content-Disposition: inline; filename="SpamAssassinReport.txt" Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-Mailer: MIME-tools 5.417 (Entity 5.417) Spam detection software, running on the system "islay.ee.columbia.edu", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see abuse@xxxxxxxx for details. Content preview: Dear, I plan to measure the microphone sensitivity of a Knowles TM series microphone that is typically installed in hearing aids. My problem is that the microphone output response is extremely low (0.18mV to 73 dB SPL) so that I feel that I have to use a high gain pre-amplifier possiblly as much as about 60 dB. Does anyone know any good commercial preamplifer for this purpose or any alternative way? Thank you in advance for your suggestions. [...] Content analysis details: (6.3 points, 6.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 UNPARSEABLE_RELAY Informational: message has unparseable relay lines 1.2 HTML_IMAGE_ONLY_20 BODY: HTML: images with 1600-2000 bytes of words 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 BAYES_50 BODY: Bayesian spam probability is 40 to 60% [score: 0.4499] 0.0 MIME_HTML_ONLY BODY: Message only has text/html MIME parts 3.2 NO_DNS_FOR_FROM DNS: Envelope sender has no MX or A DNS records 1.1 HTML_MIME_NO_HTML_TAG HTML-only message, but there is no HTML tag 0.9 HTML_SHORT_LINK_IMG_3 HTML is very short with a linked image ------------=_1148656249-22460-86--