<div dir="ltr">TL064 is too noisy and almost too slow in this application.<div><br></div><div>I've used it
<span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">to save power<span> </span></span>in oscillators though, where the level is always maximized and noise level less of an issue.</div><div><br></div><div>/mr</div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On 21 March 2018 at 10:57, Roman Sowa <span dir="ltr"><<a href="mailto:modular@go2.pl" target="_blank">modular@go2.pl</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Why not use TL064, or TL034 if lower input offset voltage needed<br>
<br>
Roman<br>
<br>
W dniu 2018-03-21 o 10:41, Mattias Rickardsson pisze:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">
On 19 March 2018 at 23:48, Jay Schwichtenberg <<a href="mailto:jschwich53@comcast.net" target="_blank">jschwich53@comcast.net</a> <mailto:<a href="mailto:jschwich53@comcast.net" target="_blank">jschwich53@comcast.net</a><wbr>>> wrote:<br>
<br>
To me it seems like chips running at 50C-60C is way too hot and<br>
something is wrong. I'd expect to see something like a voltage<br>
regulator dropping a lot of voltage under a decent load doing that.<br>
<br>
<br>
55-60 degrees C was measured in the absolute middle of the top of the IC, and the edges are a bit cooler. The PCB around it is 45 degrees, so it's just 10-15 degrees above that.<br>
<br></span>
____<span class=""><br>
<br>
Are you driving low impedance loads or something?<br>
<br>
<br>
Not extremely low, maybe 10k-20k on average - the quiescent currents are still the majority of currents drawn by the ICs.<br>
<br>
But it adds up to some heat when having lots of TTSOP quad op-amps and SOIC VCAs in a fairly small area, and all the passives on the bottom side of the PCB.<br>
<br>
/mr<br>
<br>
<br>
<br></span>
*From:*Synth-diy [mailto:<a href="mailto:synth-diy-bounces@synth-diy.org" target="_blank">synth-diy-bounces@synt<wbr>h-diy.org</a><br>
<mailto:<a href="mailto:synth-diy-bounces@synth-diy.org" target="_blank">synth-diy-bounces@synt<wbr>h-diy.org</a>>] *On Behalf Of *Mattias<br>
Rickardsson<br>
*Sent:* Monday, March 19, 2018 7:10 AM<br>
*To:* mark verbos<br>
*Cc:* <a href="mailto:synth-diy@synth-diy.org" target="_blank">synth-diy@synth-diy.org</a> <mailto:<a href="mailto:synth-diy@synth-diy.org" target="_blank">synth-diy@synth-diy.or<wbr>g</a>><br>
*Subject:* Re: [sdiy] Latvian CEM Synth IC clones____<br>
<br>
__ __<span class=""><br>
<br>
On 14 March 2018 at 11:50, mark verbos <<a href="mailto:markverbos@gmail.com" target="_blank">markverbos@gmail.com</a><br></span>
<mailto:<a href="mailto:markverbos@gmail.com" target="_blank">markverbos@gmail.com</a>>> wrote:____<span class=""><br>
<br>
Sorry if this is a stupid question, but when does it start to be an<br>
issue that the parts are too small. I mean in terms of current<br></span>
capacity and such. ____<br>
<br>
__ __<span class=""><br>
<br>
One problem resulting from the tinyfication of everything is that<br>
the temperature gets higher when many ICs are packed into a small<br>
PCB area. My VCAs are running at over 50 degrees C here on the<br>
bench. The op-amps are approaching 60 degrees. When something<br></span>
reaches 180 degrees, we have an uncool audio fatality. ;-)____<br>
<br>
__ __<span class=""><br>
<br>
I use 0603 resistors and they are only 100mW at some point it<br>
starts to be an issue for analog circuits, right? Not that I<br>
really want to use 01005 passives anyway, but my pick ’n' place<br></span>
is supposed to be able to. They look like salt and pepper.____<br>
<br>
__ __<span class=""><br>
<br>
Surface-mount resistors with larger physical size typically have a<br>
bit lower excess noise and distortion. Size matters also among<br></span>
capacitors to some degrees. For some designs this can be important.____<br>
<br>
__ __<span class=""><br>
<br>
The ability to probe your ICs without shorting things is a good<br>
goal. With quad op-amps (outputs on the corner pins) TTSOP is fine,<br></span>
but otherwise I prefer the huge SOIC to reduce the risks.____<br>
<br>
__ __<br>
<br>
/mr____<br>
<br>
__ __<span class=""><br>
<br>
<br>
<br>
<br>
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</span></blockquote>
</blockquote></div><br></div>