<div dir="ltr">I think they're used in ribbon mic preamps like the Cloudlifter. <div><br></div><div>See US Pat. 9.167,327B1</div><div><br></div></div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Sat, 21 Jun 2025 at 08:51, Mike Bryant <<a href="mailto:mbryant@futurehorizons.com">mbryant@futurehorizons.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div class="msg-3973637501124634005">
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The difference to most other dual JFETs is they are on the same silicon die, so are inherently better matched. </div>
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Zetex are one of the biggest suppliers of duals - bipolar, JFET and MOSFET - but they always use two die in the same package and these could come from different locations on the wafer so won't be quite as well matched, nor are they so well thermally bonded.</div>
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That said, in most applications this isn't really an issue. I think the very low noise space probe detectors is the only application that really needs them.</div>
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<b>From:</b> Synth-diy <<a href="mailto:synth-diy-bounces@synth-diy.org" target="_blank">synth-diy-bounces@synth-diy.org</a>> on behalf of Roman Sowa via Synth-diy <<a href="mailto:synth-diy@synth-diy.org" target="_blank">synth-diy@synth-diy.org</a>><br>
<b>Sent:</b> 21 June 2025 05:12<br>
<b>To:</b> <a href="mailto:synth-diy@synth-diy.org" target="_blank">synth-diy@synth-diy.org</a> <<a href="mailto:synth-diy@synth-diy.org" target="_blank">synth-diy@synth-diy.org</a>><br>
<b>Subject:</b> Re: [sdiy] Dual Matched N JFET from Linear</div>
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<div style="font-size:11pt">Reading just a few lines from the site reveals this is some audiophile<br>
mumbo jumbo, so possibly very high price, and not so much better than<br>
other dual jFETs.<br>
Let me check... yes, the price is about 10x higher than others. One<br>
popular store lists 98 various dual jFETs.<br>
I mean, this is rather destined for discrete audio amps, so why bother f<br>
there are so many over the top opamps cheaper than those FETs. Surely<br>
for experimenter and audiophile market.<br>
<br>
Roman<br>
<br>
W dniu 2025-06-20 o 22:34, Tim Parkhurst via Synth-diy pisze:<br>
> Hey, Analog Hounds,<br>
><br>
> Linear Systems is promoting a new Matched Dual JFET, and you might<br>
> even be able to get a sample or two. Useful? Not?<br>
><br>
> <a href="https://www.linearsystems.com/post/why-engineers-choose-the-lsk389-for-high-precision-analog-design?utm_campaign=d2b0395f-db24-487d-8e02-adcff714e7a8&utm_source=so&utm_medium=mail&cid=a05ef50a-a9c5-473d-950b-37f3f1a2d83d" id="m_-3973637501124634005OWA082fa624-3c01-932b-5ed3-6dabe7cc6615" target="_blank">
https://www.linearsystems.com/post/why-engineers-choose-the-lsk389-for-high-precision-analog-design?utm_campaign=d2b0395f-db24-487d-8e02-adcff714e7a8&utm_source=so&utm_medium=mail&cid=a05ef50a-a9c5-473d-950b-37f3f1a2d83d</a><br>
> <<a href="https://www.linearsystems.com/post/why-engineers-choose-the-lsk389-for-high-precision-analog-design?utm_campaign=d2b0395f-db24-487d-8e02-adcff714e7a8&utm_source=so&utm_medium=mail&cid=a05ef50a-a9c5-473d-950b-37f3f1a2d83d" id="m_-3973637501124634005OWA1497be88-225b-3593-25ae-e8b187ebf58e" target="_blank">https://www.linearsystems.com/post/why-engineers-choose-the-lsk389-for-high-precision-analog-design?utm_campaign=d2b0395f-db24-487d-8e02-adcff714e7a8&utm_source=so&utm_medium=mail&cid=a05ef50a-a9c5-473d-950b-37f3f1a2d83d</a>><br>
><br>
> Tim (define "useful") Servo<br>
> ---<br>
> "Imagination is more important than knowledge." - Albert Einstein<br>
><br>
><br>
><br>
><br>
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