<div fr-original-style="" style="box-sizing: border-box; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent;">Hi Ben, Bob, Florian, and Marvin,</div><div fr-original-style="" style="box-sizing: border-box; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent;">Thanks for the tips!<br fr-original-style="" style="box-sizing: border-box; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent;">I ordered the Triad <span style="color: rgb(51, 51, 51); font-family: Arial, Helvetica, sans-serif; font-size: 13px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; float: none; display: inline !important; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent; box-sizing: border-box;" id="isPasted" fr-original-style="color: rgb(51, 51, 51); font-family: Arial, Helvetica, sans-serif; font-size: 13px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;">VPT30-830</span> <br fr-original-style="" style="box-sizing: border-box; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent;"><a target="_blank" rel="noopener noreferrer" href="https://mou.sr/42IFATi" id="isPasted" fr-original-style="" style="box-sizing: border-box; user-select: auto; scrollbar-color: var(--scrollbar-active-color) transparent; color: rgb(76, 140, 246); text-decoration: none; background: transparent; outline: none; cursor: pointer; transition: color 0.3s; touch-action: manipulation;">https://mou.sr/42IFATi</a><br fr-original-style="" style="box-sizing: border-box; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent;">although I wonder if I should have gotten the <span style="color: rgb(51, 51, 51); font-family: Arial, Helvetica, sans-serif; font-size: 13px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; float: none; display: inline !important; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent; box-sizing: border-box;" id="isPasted" fr-original-style="color: rgb(51, 51, 51); font-family: Arial, Helvetica, sans-serif; font-size: 13px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;">VPT36-690 </span>instead<br fr-original-style="" style="box-sizing: border-box; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent;"><a target="_blank" rel="noopener noreferrer" href="https://mou.sr/41R8TSY" id="isPasted" fr-original-style="" style="box-sizing: border-box; user-select: auto; scrollbar-color: var(--scrollbar-active-color) transparent; color: rgb(76, 140, 246); text-decoration: none; background: transparent; outline: none; cursor: pointer; transition: color 0.3s; touch-action: manipulation;">https://mou.sr/41R8TSY</a><br fr-original-style="" style="box-sizing: border-box; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent;">Plus a few <span style="color: rgb(51, 51, 51); font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Ubuntu, Helvetica, Arial, sans-serif; font-size: 14.5px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; float: none; display: inline !important; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent; box-sizing: border-box;" id="isPasted" fr-original-style="color: rgb(51, 51, 51); font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Ubuntu, Helvetica, Arial, sans-serif; font-size: 14.5px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;">CUI P7805B-1000 5V regulators. will report back tomorrow night.</span><br fr-original-style="" style="box-sizing: border-box; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent;"><br fr-original-style="" style="box-sizing: border-box; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent;"><span id="isPasted" fr-original-style="" style="box-sizing: border-box; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent;">PS. These tariffs are no joke, even on an order of $59, it's an additional $10 in tariffs. I really feel for those who are reevaluating their business model altogether right now (Retroaktiv specifically, but just about everyone else). There should be a tariff exemption until the completed module/synth/device ships, not just every step of the way. </span><br fr-original-style="" style="box-sizing: border-box; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent;"><span fr-original-style="" style="box-sizing: border-box; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent;">Going to be a GREAT next 4 years. <span class="theme-emoji">😭</span></span><br fr-original-style="" style="box-sizing: border-box; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent;"><br fr-original-style="" style="box-sizing: border-box; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent;"><span id="isPasted" fr-original-style="" style="box-sizing: border-box; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent;">Todd </span></div><br fr-original-style="" style="box-sizing: border-box; user-select: inherit; scrollbar-color: var(--scrollbar-active-color) transparent;"><div class="fr-inner gmail_quote flockmail-quote flockmail-quote-id-<5781D504-2893-40BE-9B2B-FDDF60679C41@stuyts.nl>">
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          On Feb 4 2025, at 5:33 pm, Ben Stuyts <ben@stuyts.nl> wrote:
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            (Sorry, just saw that the Recom has quite a bit of noise on its output. The CUI P7805B-1000 is a better choice.)<br id="lineBreakAtBeginningOfMessage"><div style="display:block"><br><blockquote type="cite" style="display:block;-webkit-margin-before:1__qem;-webkit-margin-after:1em;-webkit-margin-start:40px;-webkit-margin-end:40px"><div style="display:block">On 4 Feb 2025, at 23:26, Ben Stuyts <ben@stuyts.nl> wrote:</div><br class="Apple-interchange-newline"><div style="display:block"><span style="caret-color:rgb(0, 0, 0);font-family:Helvetica;font-size:14px;font-style: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;-webkit-text-stroke-width:0px;text-decoration:none;float:none;display:inline !important">One more thought:</span><div style="display:block;caret-color:rgb(0, 0, 0);font-family:Helvetica;font-size:14px;font-style: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;-webkit-text-stroke-width:0px;text-decoration:none"><br></div><div style="display:block;caret-color:rgb(0, 0, 0);font-family:Helvetica;font-size:14px;font-style: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;-webkit-text-stroke-width:0px;text-decoration:none">There are DC/DC converters with the same pinout as a 7805. So what you could do is:</div><div style="display:block;caret-color:rgb(0, 0, 0);font-family:Helvetica;font-size:14px;font-style: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;-webkit-text-stroke-width:0px;text-decoration:none"><br></div><div style="display:block;caret-color:rgb(0, 0, 0);font-family:Helvetica;font-size:14px;font-style: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;-webkit-text-stroke-width:0px;text-decoration:none">- remove the 7805 and rectifier for the 5V section.</div><div style="display:block;caret-color:rgb(0, 0, 0);font-family:Helvetica;font-size:14px;font-style: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;-webkit-text-stroke-width:0px;text-decoration:none">- Put a DC/DC converter in it’s place, e.g. a Recom R-78E5.0-1.0 (input is 8-28V, output is 5V, 1A max)</div><div style="display:block;caret-color:rgb(0, 0, 0);font-family:Helvetica;font-size:14px;font-style: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;-webkit-text-stroke-width:0px;text-decoration:none">- Wire the input to the +20V input of the 15V section.<br id="lineBreakAtBeginningOfMessage"><div style="display:block"><br></div><div style="display:block">DC/DC converters are very efficient and can handle the drop from 20 to 5V easily without breaking a sweat. An analog part like the 7805 would dissipate a ton of heat.</div><div style="display:block"><br></div><div style="display:block">Ben</div><div style="display:block"><br><blockquote type="cite" style="display:block;-webkit-margin-before:1__qem;-webkit-margin-after:1em;-webkit-margin-start:40px;-webkit-margin-end:40px"><div style="display:block">On 4 Feb 2025, at 23:15, Ben Stuyts <<a href="mailto:ben@stuyts.nl">ben@stuyts.nl</a>> wrote:</div><br class="Apple-interchange-newline"><div style="display:block"><div style="display:block;overflow-wrap:break-word;-webkit-nbsp-mode:space;line-break:after-white-space">Yes, that should work for the lower part, the +/- 15V section. It can deliver 1.67A when the windings are in series, not 3.34A. But that is more than plenty for this application.<div style="display:block"><br></div><div style="display:block">For the 5V you need a separate winding, for the reasons Bob explained. You can use a separate transformer for this, it doesn’t need to come from the same transformer. Looking at the schematic, a 5VA or 10VA type should be sufficient.</div><div style="display:block"><br></div><div style="display:block">Another possibility without an added winding is to add a small DC/DC converter on the +20V line, and pre-regulate it to 8V. A 5W type is probably enough. Feed this into the input of 7805. You could even take out the 7805 and use a DC/DC converter which outputs 5V directly, depending how purist you are. ;-)</div><div style="display:block"><br></div><div style="display:block">Ben</div><div style="display:block"><br id="lineBreakAtBeginningOfMessage"><div style="display:block"><br><blockquote type="cite" style="display:block;-webkit-margin-before:1__qem;-webkit-margin-after:1em;-webkit-margin-start:40px;-webkit-margin-end:40px"><div style="display:block">On 4 Feb 2025, at 23:05, Todd Sines <sines_list@scale.la> wrote:</div><br class="Apple-interchange-newline"><div style="display:block"><div fr-original-style="" style="display:block;box-sizing:border-box">I have a Triad VPT30-1670, which is a dual 15V output toroidal transformer at 3.34 A.<br fr-original-style="" style="box-sizing:border-box">I would think that would work, but maybe I'm missing something?<br fr-original-style="" style="box-sizing:border-box"><br fr-original-style="" style="box-sizing:border-box">The schematic is here:</div><div fr-original-style="" style="display:block;box-sizing:border-box"><a href="https://www.synthxl.com/wp-content/uploads/2020/01/Roland-CMU-800-Compu-Music-Schematic.pdf" target="_blank" id="isPasted" fr-original-style="" style="box-sizing:border-box;color:rgb(76, 140, 246);text-decoration:none;background:none;outline:currentcolor;cursor:pointer;transition:color 0.3s;touch-action:manipulation">Roland-CMU-800-Compu-Music-Schematic.pdf</a></div><br fr-original-style="" style="box-sizing:border-box"></div></blockquote></div><br></div></div></div></blockquote></div><br></div><br class="Apple-interchange-newline"></div></blockquote></div><br>
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