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<DIV> Hi Ian</DIV>
<DIV> My thought process was to reproduce something <SPAN class=correction id="">functionally</SPAN> like</DIV>
<DIV> the 3080 to keep alive such designs as the <SPAN class=correction id=""><SPAN class=correction id=""><SPAN class=correction id="">asm-1s</SPAN> and others.</SPAN></SPAN></DIV>
<DIV><SPAN class=correction><SPAN class=correction> <SPAN class=correction id="">Pinout</SPAN>, footprint, and function as a drop in replacement.</SPAN></SPAN></DIV> <SPAN class=correction id="">Jeri</SPAN><BR>-----Original Message-----<BR>From: Ian Fritz <<SPAN class=correction id=""><SPAN class=correction id=""><SPAN class=correction id="">ijfritz</SPAN></SPAN></SPAN>@earthlink.net><BR>To: laxt57@aol.com; synth-diy@dropmix.xs4all.nl<BR>Sent: Fri, 03 <SPAN class=correction id=""><SPAN class=correction id=""><SPAN class=correction id="">Jun</SPAN></SPAN></SPAN> 2005 09:45:13 -0600<BR>Subject: Re: [<SPAN class=correction id=""><SPAN class=correction id=""><SPAN class=correction id="">sdiy</SPAN></SPAN></SPAN>] Humans are not Becoming Smaller<BR><BR>
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<DIV class=AOLPlainTextBody id=AOLMsgPart_0_e9c6c75f-e620-462d-af2f-fd5dcda96090>At 12:47 PM 6/2/05, <A href="mailto:laxt57%40aol.com">laxt57@aol.com</A> wrote: <BR> <BR>> Well what I am planning is this. A <SPAN class=correction id=""><SPAN class=correction id=""><SPAN class=correction id="">OTA</SPAN></SPAN></SPAN> made with <SPAN class=correction id=""><SPAN class=correction id=""><SPAN class=correction id="">SMD</SPAN></SPAN></SPAN> that <BR>> will fit the footprint of a <SPAN class=correction id=""><SPAN class=correction id=""><SPAN class=correction id="">ca3080</SPAN></SPAN></SPAN>. By input I guess I was not <BR>> asking about the design of the <SPAN class=correction id=""><SPAN class=correction id=""><SPAN class=correction id="">OTA</SPAN></SPAN></SPAN> itself, all that is freely <BR>> available on the web. I guess my question is with the available <BR>> <SPAN class=correction id=""><SPAN class=correction id=""><SPAN class!
=correction id="">smd</SPAN></SPAN></SPAN> devices 847s,3904 etc do you think this <SPAN class=correction id=""><SPAN class=correction id="">sdiy</SPAN></SPAN> do able? <BR> <BR>Well, that's the question. I haven't found any good <SPAN class=correction id=""><SPAN class=correction id=""><SPAN class=correction id="">SMD</SPAN></SPAN></SPAN> well-matched, high-gain transistors. I've been stocking up on the popular Japanese matched pairs, some of which are quite good, but all discontinued. In my most recent discrete <SPAN class=correction id=""><SPAN class=correction id=""><SPAN class=correction id="">OTA</SPAN></SPAN></SPAN> I tried a pair of hand-matched <SPAN class=correction id=""><SPAN class=correction id=""><SPAN class=correction id="">ZTX795A's</SPAN></SPAN></SPAN> glued together, but they didn't work very well. They had too much <SPAN class=correction id=""><SPAN class=correction id=""><SPAN class=correction id="">LF</SPAN></SPAN></SPAN> noise, presumably due!
to temperature fluctuations. <BR> <BR>Maybe some of!
the non
-monolithic <SPAN class=correction id=""><SPAN class=correction id=""><SPAN class=correction id="">SDMs</SPAN></SPAN></SPAN> could be made to work, I <SPAN class=correction id=""><SPAN class=correction id=""><SPAN class=correction id="">dunno</SPAN></SPAN></SPAN>. <BR> <BR>Another question is whether it is even a good idea to try to reproduce the 3080. The <SPAN class=correction id=""><SPAN class=correction id=""><SPAN class=correction id="">Iabc</SPAN></SPAN></SPAN> mirror has always been a pain, requiring a mirror in the <SPAN class=correction id=""><SPAN class=correction id=""><SPAN class=correction id="">expo</SPAN></SPAN></SPAN> converter. Why not work with the simpler discrete designs that don't have this "feature". <BR> <BR> Ian <BR> <BR></DIV><!-- end of AOLMsgPart_0_e9c6c75f-e620-462d-af2f-fd5dcda96090 --></DIV></DIV></BODY></HTML>