<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);">Thanks René!</span><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);"><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);"><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);">Richie</span><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);"><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);">2 coffees down and page 6 of the SM tells me you are probably right:</span><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);"><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);"><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);">LFO (as well as ADSR) are software-generated, so almost certainly given the modulation architecture, the noise source is too</span><div><font color="#000000"><span style="caret-color: rgb(0, 0, 0);"><br></span></font></div><div><font color="#000000"><span style="caret-color: rgb(0, 0, 0);"><br></span></font></div><div><img src="cid:3B19F64A-22A2-461A-9C14-266128660E94" alt="grab 2026-01-20 at 08.33.49.png" width="480.5"></div><div><font color="#000000"><span style="caret-color: rgb(0, 0, 0);"><br id="lineBreakAtBeginningOfMessage"></span></font><div><br><blockquote type="cite"><div>On 20 Jan 2026, at 07:31, rburnett@richieburnett.co.uk wrote:</div><br class="Apple-interchange-newline"><div><div>That's interesting Adam. I didn't know the JX-3P could do that!<br><br>I don't see a modulation path from the analogue noise source to the DCOs though, so I guess the noise modulation you mention must be done digitally by the micro?<br><br>-Richie,<br><br><br>On 2026-01-18 21:52, Adam (synthDIY) wrote:<br><blockquote type="cite">I wonder if it has something to do with the noise modulation option in the JX3P, rather than just the use of noise as part of the patch mix?<br>Noise modulation is available from the front panel but not from the PG-200<br>A<br><blockquote type="cite">On 19 Jan 2026, at 05:47, Richie Burnett <rburnett@richieburnett.co.uk> wrote:<br>Thanks for the confirmation everyone.<br>It just seemed like a strange thing to include what must have been an expensive BA662 OTA device at the time, instead of using yet another trim-pot to calibrate the noise level.<br>Obviously the AGC approach would try to correct for long-term drift of the noise level and possible variation with temperature, but that can't account for that much amplitude variation, and the user can adjust the level of noise in the mix anyway! I would have thought the AGC circuit would need to measure the RMS of the noise in order to accurately control its perceived loudness anyway?<br>It's interesting that it's used in other synths of the era like the Juno 6 & 60 and a variant in the Jupiter 6, but the Juno 106 design went back to using a trim-pot again (VR32). (See attached.)<br>JX-8P and the Alpha Juno / MKS50 got the luxury of digital noise sources!<br>-Richie,<br>-----Original Message----- From: Florian Anwander via Synth-diy<br>Sent: Sunday, January 18, 2026 6:15 PM<br>To: synth-diy mailing list<br>Subject: Re: [sdiy] JX-3P question<br>Hello Richie<br>Am 18.01.26 um 18:13 schrieb Richie Burnett:<br>but on closer inspection it looks like the OTA is in some sort of local feedback loop, intended to keep the noise amplitude constant, maybe?<br>I never investigated deeper on this circuit, but that is my impression too. Roland used that in the JX3P and in the Juno6/60. A similar circuit was used in the Jupiter6:<br>I don't remember the JP8.<br>Florian<br>________________________________________________________<br>This is the Synth-diy mailing list<br>Submit email to: Synth-diy@synth-diy.org<br>View archive at: https://synth-diy.org/pipermail/synth-diy/<br>Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy<br>Selling or trading? Use marketplace@synth-diy.org<br>--<br>This email has been checked for viruses by AVG antivirus software.<br>www.avg.com<Juno106-Noise.PNG>________________________________________________________<br>This is the Synth-diy mailing list<br>Submit email to: Synth-diy@synth-diy.org<br>View archive at: https://synth-diy.org/pipermail/synth-diy/<br>Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy<br>Selling or trading? Use marketplace@synth-diy.org<br></blockquote></blockquote>________________________________________________________<br>This is the Synth-diy mailing list<br>Submit email to: Synth-diy@synth-diy.org<br>View archive at: https://synth-diy.org/pipermail/synth-diy/<br>Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy<br>Selling or trading? Use marketplace@synth-diy.org<br></div></div></blockquote></div><br></div></body></html>