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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I’ve been using SMPS in pro-audio equipment we design since the 1970s, as have most of the other top audio designers I know. Some took until the late 90s to
come round but from then on everybody who mattered accepted SMPS were better.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">High frequency current spikes indicate a badly designed SMPS, nothing more. A good one using multi-phase zero-crossing switching will show none of that.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Have a look inside every pro-audio product nowadays and you’ll find a SMPS. And to be sold they have to pass mains radiated tests so there is very little mains-side
noise. Indeed it is linear supplies which often used to fail those tests as they distorted the mains signal more due to core hysteresis.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">So I will submit that you have a somewhat jaundiced view.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Synth-diy [mailto:synth-diy-bounces@synth-diy.org]
<b>On Behalf Of </b>Josh Nursing via Synth-diy<br>
<b>Sent:</b> 02 August 2022 16:47<br>
<b>To:</b> synth-diy@synth-diy.org<br>
<b>Subject:</b> Re: [sdiy] Help with Jupiter 8 clone<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">SMPS are the most polluting/noisy PSUs for audio purposes. Lots of high-frequency current spikes affect both downstream circuits and the mains they're connected to.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">And before you start telling me about filtering the output of them, that does absolutely nothing for the mains-side noise.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Effects on audio are across the board - all audio frequencies suffer, and it's probably more noticeable in loss of bass frequencies.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Tue, Aug 2, 2022 at 11:41 AM Mike Bryant <<a href="mailto:mbryant@futurehorizons.com">mbryant@futurehorizons.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">How can audio suffer from putting a PSU in with 100 times better performance ? No 50/100Hz at
all and general noise almost zero. And it’s far less heat so everything else runs cooler and better. I think too many people see the noise from their phone charger or whatever and assume a proper SMPS is like that.</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Synth-diy
[mailto:<a href="mailto:synth-diy-bounces@synth-diy.org" target="_blank">synth-diy-bounces@synth-diy.org</a>]
<b>On Behalf Of </b>Josh Nursing via Synth-diy<br>
<b>Sent:</b> 02 August 2022 16:35<br>
<b>To:</b> Synth DIY<br>
<b>Subject:</b> Re: [sdiy] Help with Jupiter 8 clone</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">I really don't like the idea of replacing the linear PSU in those vintage synths with a SMPS one. Audio suffers.<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">On Tue, Aug 2, 2022 at 7:45 AM Adam (synthDIY) <<a href="mailto:synthdiy@adambaby.com" target="_blank">synthdiy@adambaby.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Luís, I assume you’re aware of this<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><a href="https://synthronics.de/roland-jupiter-8-new-psu/" target="_blank">https://synthronics.de/roland-jupiter-8-new-psu/</a><o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">and this guy, who has been ominously quiet of late<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><a href="https://jup8restoration.wordpress.com/2019/10/22/new-power-supply-being-manufactured-for-a-jupiter-8/" target="_blank">https://jup8restoration.wordpress.com/2019/10/22/new-power-supply-being-manufactured-for-a-jupiter-8/</a><o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">A<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:12.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">On 2 Aug 2022, at 3:57 am, Luís Marka via Synth-diy <<a href="mailto:synth-diy@synth-diy.org" target="_blank">synth-diy@synth-diy.org</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Hi guys,<br>
<br>
I am giving a serious thought about building a Jupiter 8 clone, and started to take a deeper look at the schematics (actually I already ordered some of the parts, so it looks like I will get it done eventually). In the PSU there are three GP-30G diodes tied
at the -15, +15 and +5V outputs, listed as "Hi-Fi Special" both in the schematics and in the parts list. I never heard anything about a "hi-fi special" diode, any idea what that means??<br>
<br>
Cheers!<br>
<br>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">_______________________________________________<br>
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Selling or trading? Use <a href="mailto:marketplace@synth-diy.org" target="_blank">
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