<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><br class=""><div><blockquote type="cite" class=""><div class="">On 25 Apr 2018, at 16:29, KD KD <<a href="mailto:pic24hj@gmail.com" class="">pic24hj@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class=""><blockquote type="cite" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none;" class="">Tom<br class="">Alfa have got all kinds of good stuff in the pipeline, from what they told me:<br class="">a quad OTA based on the 13700 (but without the stupid buffers) called the<br class="">AS13704, and a modern clone of the CA3280, AS3280. Also a AS3394E<br class="">described as an “Extended” CEM3394. Sounds very interesting.<br class=""></blockquote><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">The 13600 buffers is not stupid, just what they bothered to do back</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">in the day for what was required on the request from el-organ</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">manufacturers apparently.</span></div></div></blockquote></div><br class=""><div class="">Yeah, ok. Maybe “stupid” is a bit strong. But I’d much rather have had an op-amp there instead, even if it was only a 741-type thing. Then you could have done a unity-gain follower for your OTA Cap-to-ground style filters, or an inverting integrator, and you’d also be able to implement a proper I-to-V stage for VCA applications, which gives a much better result than a resistor to ground followed by the buffer.</div><div class=""><br class=""></div><div class="">Anyway, I can see why Alfa left them off. Many, or even “most”, designs with the 13600/13700 seem to leave them out. I only really see them used in stompbox circuits where minimal parts seems to be a more important design objective then overall quality.</div><div class=""><br class=""></div><div class="">Tom</div><div class=""><br class=""></div><div class=""><div class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div>==================<br class=""> Electric Druid<br class="">Synth & Stompbox DIY<br class="">==================</div><div class=""><br class=""></div></div></div></div></body></html>