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A problem I saw in the mid-80s was a connector company (can't remember which) using 'selective gold plating' to just coat where the two connectors touched so as to save on gold which at the time had just boomed in price. </div>
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So in humid atmospheres the connector eventually failed at the point where the gold plating ended and the tin plating used for the rest of the connector began.</div>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Synth-diy <synth-diy-bounces@synth-diy.org> on behalf of Michael E Caloroso via Synth-diy <synth-diy@synth-diy.org><br>
<b>Sent:</b> 13 January 2026 04:52<br>
<b>To:</b> Ben Stuyts <ben@stuyts.nl><br>
<b>Cc:</b> brianw <brianw@audiobanshee.com>; Synth-diy <synth-diy@synth-diy.org><br>
<b>Subject:</b> Re: [sdiy] Roland pin header connectors</font>
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<div dir="ltr">Yes I did read it.
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<div>I have several references on dissimilar metals for interconnects in my library that I just reviewed. They do not correlate 100%.</div>
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<div>I would say that the differences among OEMs and experts comes down to the alloys they use for plating. Gold plating is not always 24ct, and tin plating can contain other metals..</div>
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<div>From my experience, I'd say I got lucky with my selection of interconnects. Whatever ARP had originally installed seemed to be reliable.</div>
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<div>MC</div>
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<div dir="ltr" class="x_gmail_attr">On Mon, Jan 12, 2026 at 5:27 PM Ben Stuyts <<a href="mailto:ben@stuyts.nl">ben@stuyts.nl</a>> wrote:<br>
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<div style="line-break:after-white-space">It’s great that it works for you.
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<div>I am not a metallurgist so I have to rely on the info from e.g. Molex as in the link I provided (did you have a chance to read it?). But I’ve been told the same thing by an FAE from out then Molex-distributor as far back as the mid eighties. And more recently
from Würth Electronik. So for optimum reliability for audio I would swap both the pcb and the cable part for gold-plated. Not that I have ever done that. I just clean or replace the tin-plated contacts on both ends and apply a tiny film of conductive grease
(MG Chem. 846, but Multicomp has a cheaper alternative nowadays).</div>
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<div>Ben<br id="x_m_-6130642629865584858lineBreakAtBeginningOfMessage">
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<blockquote type="cite">
<div>On 12 Jan 2026, at 02:53, Michael E Caloroso <<a href="mailto:mec.forumreader@gmail.com" target="_blank">mec.forumreader@gmail.com</a>> wrote:</div>
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<div dir="ltr">I've been using mixed gold/tin contact interconnects in my vintage synths since the 1990s and have yet to suffer any failures.
<div><br>
<div>My ARP ProSoloist built in 1973 has mixed gold/tin contact interconnects and they are still reliable. Alan Pearlman used to design electronics for the military and space industry before starting ARP. I also have experience in military electronics.</div>
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<div>I bought my Memorymoog new in 1986; by the mid 1990s the tin plated interconnects had corroded beyond repair and I replaced them with mixed tin/gold interconnects. The Memorymoog stayed in tune much better and was more reliable.</div>
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<div>Tin plated contacts are rated for ten year life. Gold plated contacts are rated for tens of years.</div>
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<div>According to a metallurgist, the key factor is salt in the air IE coastal areas. Salt from ocean waters will trigger the corrosion.</div>
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<div>MC</div>
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<div dir="ltr" class="x_gmail_attr">On Sun, Jan 11, 2026 at 7:38 AM Ben Stuyts via Synth-diy <<a href="mailto:synth-diy@synth-diy.org" target="_blank">synth-diy@synth-diy.org</a>> wrote:<br>
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<blockquote class="x_gmail_quote" style="margin:0px 0px 0px 0.8ex; border-left-width:1px; border-left-style:solid; border-left-color:rgb(204,204,204); padding-left:1ex">
<div style="line-break:after-white-space">I recommend against mixing tin and gold plated mated connectors. If upgrading to gold you have to upgrade both sides. Otherwise the contact point can (will?) disintegrate over time because of galvanic and fretting corrosion.
See <a href="https://www.molex.com/en-us/blog/gold-or-tin-vs-gold-and-tin" target="_blank">https://www.molex.com/en-us/blog/gold-or-tin-vs-gold-and-tin</a>
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<div>Ben <br id="x_m_-6130642629865584858m_-5627934322829017498lineBreakAtBeginningOfMessage">
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<blockquote type="cite">
<div>On 10 Jan 2026, at 03:08, brianw <<a href="mailto:brianw@audiobanshee.com" target="_blank">brianw@audiobanshee.com</a>> wrote:</div>
<br>
<div><span style="font-family:Menlo-Regular; 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; text-decoration:none; float:none; display:inline">Yep.
You can see that Mouser lists the Mfr # as 22-27-2081, which matches the Molex site.</span><br style="font-family:Menlo-Regular; 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; text-decoration:none">
<br style="font-family:Menlo-Regular; 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; text-decoration:none">
<span style="font-family:Menlo-Regular; 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; text-decoration:none; float:none; display:inline">As
I mentioned, you can upgrade to gold via</span><br style="font-family:Menlo-Regular; 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; text-decoration:none">
<br style="font-family:Menlo-Regular; 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; text-decoration:none">
<a href="https://www.mouser.com/ProductDetail/Molex/22-29-2081?qs=5gBG3L055oOSpyERBqcJ9g%3D%3D" target="_blank" style="font-family:Menlo-Regular; 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">https://www.mouser.com/ProductDetail/Molex/22-29-2081?qs=5gBG3L055oOSpyERBqcJ9g%3D%3D</a><br style="font-family:Menlo-Regular; 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; text-decoration:none">
<br style="font-family:Menlo-Regular; 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; text-decoration:none">
<span style="font-family:Menlo-Regular; 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; text-decoration:none; float:none; display:inline">This
is an example where Mouser has the wrong photo, but you can tell from the<span> </span></span><a href="http://molex.com/" target="_blank" style="font-family:Menlo-Regular; 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">Molex.com</a><span style="font-family:Menlo-Regular; 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; text-decoration:none; float:none; display:inline"><span> </span>site
that 22-29-2081 is the same as 22-27-2081 except for the plating. I'm not necessarily recommending that you change to gold, but my point is that Mouser doesn't always have the right photos for every product, and they don't necessarily make it easy to find
every variation. In contrast, going directly to a manufacturer like Molex allows you to discover their full product line, and sometimes you'll discover that exactly what you need is available, even if a little bit hidden by distributor sites and databases.</span><br style="font-family:Menlo-Regular; 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; text-decoration:none">
<br style="font-family:Menlo-Regular; 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; text-decoration:none">
<span style="font-family:Menlo-Regular; 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; text-decoration:none; float:none; display:inline">On
that note, if you prefer AMP/TE Connectivity (and I use them almost as much as Molex), then it's worth a search on their site. Who knows, maybe that have something that also looks exactly like what Roland used. Obviously, I'm not recommend that you spend months
stressing over options, but it never hurts to do a quick search of all the options before buying - especially if you want to buy in bulk to save on unit cost.</span><br style="font-family:Menlo-Regular; 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; text-decoration:none">
<br style="font-family:Menlo-Regular; 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; text-decoration:none">
<span style="font-family:Menlo-Regular; 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; text-decoration:none; float:none; display:inline">Brian</span><br style="font-family:Menlo-Regular; 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; text-decoration:none">
<br style="font-family:Menlo-Regular; 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; text-decoration:none">
<br style="font-family:Menlo-Regular; 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; text-decoration:none">
<span style="font-family:Menlo-Regular; 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; text-decoration:none; float:none; display:inline">On
Jan 9, 2026, at 5:27 PM, David Moylan wrote:</span><br style="font-family:Menlo-Regular; 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; text-decoration:none">
<blockquote type="cite" style="font-family:Menlo-Regular; 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; text-decoration:none">
Awesome. Thanks! That looks exactly like the part.<br>
<br>
On 1/9/26 8:15 PM, Pete Hartman via Synth-diy wrote:<br>
<blockquote type="cite">This was what I was thinking of; I do generally get the AMP/TE Connectivity ones with locking headers, but this looks just like the one on the SH-101.<br>
<br>
<a href="https://www.mouser.com/ProductDetail/Molex/22-27-2081?qs=hSmm4fxMIuMegRKta0khbw%3D%3D" target="_blank">https://www.mouser.com/ProductDetail/Molex/22-27-2081?qs=hSmm4fxMIuMegRKta0khbw%3D%3D</a><br>
<br>
Looks like exactly the same thing Brian linked to :)<span> </span><br>
<br>
Pete<br>
<br>
On Fri, Jan 9, 2026 at 7:11 PM brianw <<a href="mailto:brianw@audiobanshee.com" target="_blank">brianw@audiobanshee.com</a>> wrote:<br>
<blockquote type="cite">If you want to upgrade to gold contacts, then this:<br>
<br>
<a href="https://www.molex.com/en-us/products/part-detail/22292081" target="_blank">https://www.molex.com/en-us/products/part-detail/22292081</a><br>
<br>
I recommend doing a search on <a href="http://molex.com/" target="_blank">molex.com</a> to narrow down on the various options until you find the exact part. Once you have the official part number, you can search for that on Mouser or DigiKey. If you end up
choosing a part that's not stocked, then at least you can compare the specifications to see what's different.<br>
<br>
Brian Willoughby<br>
<br>
<blockquote type="cite">A quick search on <a href="http://molex.com/" target="_blank">
molex.com</a> finds this:<br>
<br>
<a href="https://www.molex.com/en-us/products/part-detail/22272081" target="_blank">https://www.molex.com/en-us/products/part-detail/22272081</a><br>
<br>
<br>
On Jan 9, 2026, at 4:52 PM, Pete Hartman wrote:<br>
<blockquote type="cite"><br>
These?<br>
<br>
<sh-101-keybed.JPG><br>
<br>
I don't know about the specific style but generally I call them MTA-100 (100 = .100" pitch), I think I've seen them listed as "KK Series" and similar on Mouser as well.<br>
<br>
Pete<br>
</blockquote>
</blockquote>
</blockquote>
--<span> </span><br>
David Moylan<br>
Expedition Electronics<br>
sonic adventures!<br>
</blockquote>
</blockquote>
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