[sdiy] Roland pin header connectors

Tue Jan 13 10:42:37 CET 2026

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.
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.
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Michael E Caloroso via Synth-diy <synth-diy at synth-diy.org>
Sent: 13 January 2026 04:52
To: Ben Stuyts <ben at stuyts.nl>
Cc: brianw <brianw at audiobanshee.com>; Synth-diy <synth-diy at synth-diy.org>
Subject: Re: [sdiy] Roland pin header connectors

Yes I did read it.

I have several references on dissimilar metals for interconnects in my library that I just reviewed.  They do not correlate 100%.

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..

From my experience, I'd say I got lucky with my selection of interconnects.  Whatever ARP had originally installed seemed to be reliable.

MC

On Mon, Jan 12, 2026 at 5:27 PM Ben Stuyts <ben at stuyts.nl<mailto:ben at stuyts.nl>> wrote:
It’s great that it works for you.

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).

Ben

On 12 Jan 2026, at 02:53, Michael E Caloroso <mec.forumreader at gmail.com<mailto:mec.forumreader at gmail.com>> wrote:

I've been using mixed gold/tin contact interconnects in my vintage synths since the 1990s and have yet to suffer any failures.

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.

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.

Tin plated contacts are rated for ten year life.  Gold plated contacts are rated for tens of years.

According to a metallurgist, the key factor is salt in the air IE coastal areas.  Salt from ocean waters will trigger the corrosion.

MC

On Sun, Jan 11, 2026 at 7:38 AM Ben Stuyts via Synth-diy <synth-diy at synth-diy.org<mailto:synth-diy at synth-diy.org>> wrote:
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 https://www.molex.com/en-us/blog/gold-or-tin-vs-gold-and-tin

Ben

On 10 Jan 2026, at 03:08, brianw <brianw at audiobanshee.com<mailto:brianw at audiobanshee.com>> wrote:

Yep. You can see that Mouser lists the Mfr # as 22-27-2081, which matches the Molex site.

As I mentioned, you can upgrade to gold via

https://www.mouser.com/ProductDetail/Molex/22-29-2081?qs=5gBG3L055oOSpyERBqcJ9g%3D%3D

This is an example where Mouser has the wrong photo, but you can tell from the Molex.com<http://molex.com/> 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.

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.

Brian

On Jan 9, 2026, at 5:27 PM, David Moylan wrote:
Awesome.  Thanks!  That looks exactly like the part.

On 1/9/26 8:15 PM, Pete Hartman via Synth-diy wrote:
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.

https://www.mouser.com/ProductDetail/Molex/22-27-2081?qs=hSmm4fxMIuMegRKta0khbw%3D%3D

Looks like exactly the same thing Brian linked to :)

Pete

On Fri, Jan 9, 2026 at 7:11 PM brianw <brianw at audiobanshee.com<mailto:brianw at audiobanshee.com>> wrote:
If you want to upgrade to gold contacts, then this:

https://www.molex.com/en-us/products/part-detail/22292081

I recommend doing a search on molex.com<http://molex.com/> 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.

Brian Willoughby

A quick search on molex.com<http://molex.com/> finds this:

https://www.molex.com/en-us/products/part-detail/22272081

On Jan 9, 2026, at 4:52 PM, Pete Hartman wrote:

These?

<sh-101-keybed.JPG>

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.

Pete
--
David Moylan
Expedition Electronics
sonic adventures!

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