<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<p>Another +1 for the transistor output boost.</p>
<p>I've done similar years ago following an example from an op-amp
application note. Plenty of oomph for any headphones (and 32 ohm
speakers, too). I've also included a small relay to mute the
output on power-up and power-down.</p>
<p>- Oren<br>
</p>
<div class="moz-cite-prefix">On 8/24/21 3:09 PM, jarno.verhoeven via
Synth-diy wrote:<br>
</div>
<blockquote type="cite"
cite="mid:20210824220915.IcjSm5Q1gyyFvIcjTm8Mc2@smtp1.tb.mail.iss.as9143.net">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<div dir="auto">+1 those transistors might be hard to get, so use
bd139/bd140. Alternatively you could use bd327/bd337 for a lower
power amp.</div>
<div dir="auto">I've also built one with lme49600 (BUF634 in a
different package and marketing ) drivers, which sounds great,
but that is expensive silicon.</div>
<div dir="auto">Regards,</div>
<div dir="auto">Jarno.</div>
<div dir="auto"><br>
</div>
<div dir="auto"><br>
</div>
<div dir="auto"><br>
</div>
<div id="composer_signature" dir="auto">
<div style="font-size:85%;color:#575757" dir="auto">Sent from my
Galaxy</div>
</div>
<div dir="auto"><br>
</div>
<div><br>
</div>
<div dir="auto" style="font-size:100%;color:#000000" align="left">
<div>-------- Original message --------</div>
<div>From: Jean-Pierre Desrochers <a class="moz-txt-link-rfc2396E" href="mailto:jpdesroc@oricom.ca"><jpdesroc@oricom.ca></a> </div>
<div>Date: 24/08/2021 20:15 (GMT+01:00) </div>
<div>To: 'Mattias Rickardsson' <a class="moz-txt-link-rfc2396E" href="mailto:mr@analogue.org"><mr@analogue.org></a>, 'ulfur
hansson' <a class="moz-txt-link-rfc2396E" href="mailto:ulfurh@gmail.com"><ulfurh@gmail.com></a> </div>
<div>Cc: 'Synth DIY' <a class="moz-txt-link-rfc2396E" href="mailto:synth-diy@synth-diy.org"><synth-diy@synth-diy.org></a> </div>
<div>Subject: Re: [sdiy] headphone driver for synths </div>
<div><br>
</div>
</div>
<div class="WordSection1">
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"
lang="EN-CA">This is a circuit I built many years ago that
is still rockin !</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"
lang="EN-CA"><a
href="https://www.electroschematics.com/hifi-headphone-amplifier/"
moz-do-not-send="true">https://www.electroschematics.com/hifi-headphone-amplifier/</a></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"
lang="EN-CA"> </span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"
lang="EN-CA">Enough power for any type of headphones down to
8ohms per channel.</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"
lang="EN-CA">JP</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"
lang="EN-CA"> </span></p>
<p class="MsoNormal"><b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif""
lang="FR">De :</span></b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif""
lang="FR"> Synth-diy
[<a class="moz-txt-link-freetext" href="mailto:synth-diy-bounces@synth-diy.org">mailto:synth-diy-bounces@synth-diy.org</a>] <b>De la part de</b>
Mattias Rickardsson<br>
<b>Envoyé :</b> 24 août 2021 13:55<br>
<b>À :</b> ulfur hansson<br>
<b>Cc :</b> Synth DIY<br>
<b>Objet :</b> Re: [sdiy] headphone driver for synths</span></p>
<p class="MsoNormal"> </p>
<div>
<p class="MsoNormal">Check out the circuits in Douglas Self:
Small Signal Audio Design. Haven't had an issue with them.</p>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal">/mr</p>
</div>
</div>
<p class="MsoNormal"> </p>
<div>
<div>
<p class="MsoNormal">Den tis 24 aug. 2021 18:50ulfur hansson
via Synth-diy <<a href="mailto:synth-diy@synth-diy.org"
moz-do-not-send="true">synth-diy@synth-diy.org</a>>
skrev:</p>
</div>
<blockquote style="border:none;border-left:solid #CCCCCC
1.0pt;padding:0cm 0cm 0cm
6.0pt;margin-left:4.8pt;margin-right:0cm">
<p class="MsoNormal">hello all!<br>
<br>
i've been getting mixed results for a few yeara using
standard opamp circuits to drive headphones for my
projects. oscillations randomly seem to occur, noise
issues that disappear if i use nice outboard preamp etc...<br>
<br>
is there a more juicy/capable solution anyone can think
of? THAT corp line drivers? discrete transistor drivers?<br>
<br>
any thoughts would be greatly appreciated :)<br>
-ulfur<br>
<br>
sent from outer space<br>
_______________________________________________<br>
Synth-diy mailing list<br>
<a href="mailto:Synth-diy@synth-diy.org"
moz-do-not-send="true">Synth-diy@synth-diy.org</a><br>
<a href="http://synth-diy.org/mailman/listinfo/synth-diy"
moz-do-not-send="true">http://synth-diy.org/mailman/listinfo/synth-diy</a><br>
Selling or trading? Use <a
href="mailto:marketplace@synth-diy.org"
moz-do-not-send="true">marketplace@synth-diy.org</a></p>
</blockquote>
</div>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<pre class="moz-quote-pre" wrap="">_______________________________________________
Synth-diy mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Synth-diy@synth-diy.org">Synth-diy@synth-diy.org</a>
<a class="moz-txt-link-freetext" href="http://synth-diy.org/mailman/listinfo/synth-diy">http://synth-diy.org/mailman/listinfo/synth-diy</a>
Selling or trading? Use <a class="moz-txt-link-abbreviated" href="mailto:marketplace@synth-diy.org">marketplace@synth-diy.org</a>
</pre>
</blockquote>
</body>
</html>