MOTM-style power connectors

[thundarr]

Hi folks,

I've been looking into getting my synth modules powered (when I get them built, I like planning ahead ), and have tracked down a few suppliers for MOTM-style MTA-156 connectors. I was thinking I would power my MFOS modules using the MFOS power supply linked to a separate stripboard with a few of these connectors in parallel, then when I get round to making/obtaining a 15V supply I would have a surplus of connectors to add any compatible modules.

Before I go and splash out some cash, I figured I had best find out a little more about these beasts.

Firstly, can anyone suggest a cheaper, easier or better alternative? I don't like the idea of hard-wiring the power in for the modules.

Secondly, is a crimping tool required to make suitable cables from the connectors, or does it just make the job easier?

[magman]

Hi Thundarr,

There are two kinds of MTA-156 connectors as far as I know, IDC (Insulation Displacement Connector) or crimp. The IDC method is great if you are going to make a lot of this kind of connection in a production environment, but the crimp option is in my opinion better for the DIYer.

You don't have to go to the expense of a Molex crimp tool either. I know of some people on the forum who just solder the connections then bend over the tabs with pliers so the crimps fit in the housing, but I treated myself to one of these tools from Rapid:

http://www.rapidonline.com/productinfo.aspx?&tier1=Tools%2c+Fasteners+%26+Production+Equipment&tier2=Hand+Tools&tier3=Tacking+%26+Crimping&tier4=Crimping+tool+for+PCB+connectors&moduleno=30535&catref=85-0262&kw=85-0262

Which works for both the MTA-156 and MTA-100 style crimps. Some people also use a belt and braces approach, by soldering the crimped terminal as well.

As regards the power distribution, there are a couple of distribution boards available that you can make use of. I've used the 'Dizzy' from Oakley in my modular and it works fine for me

http://www.oakleysound.com/dizzy.htm

but there are similar boards available from Ken Stone (CGS), Elby and Synthesis Technology.

Hope this helps and good luck on your build.

Regards

Magman

[fluxmonkey]

there is a t-handle tool for the IDC connectors that makes it super-easy... abt $20 if i remember, and well worth it. note that IDCs are speced for different gauges of wire, so make sure to match the connector to the wire you'll be using. +1 for the kenStone boards, as well.

b

[thundarr]

Many thanks for the advice.

I think I'll go for crimps, especially if that means I don't have to worry about different sizes of wire

I had been looking at the Ken Stone power distribution board, but it seemed that all I needed to do to was line up a load of connectors on some stripboard. Am I missing something here?

[fluxmonkey]

[magman]

In its most basic version, these power distribution systems are a straight bus, like in the CGS versions.

The Oakley Dizzy comes closer to what is called a "Star" distribution, it is actually 4 sets of 3 connectors linked back to the main power connection input. Synthesizers.Com don't actually use busboard PCB's at all, just a wiring harness, to get a full star distribution for their power loom, as here:

http://www.synthesizers.com/power.html

A star distribution decreases the influence that one modules power demands can have on the other modules. For example, using the CGS board, if the power is input on connector 1, a module plugged into connector 2 could demand enough power on the +15V to lower the voltage supplied to the rest of the connectors on the bus for a short period.

You could always for-go the Distribution board altogether and use the Synthesizers.com wiring loom method. I just preferred the distribution method myself, as the wiring can be routed neater more easily.

Regards

Magman

[RSFC]

I'll try to make my long story short as I bump thing. My initial DIY has been to work with euro standards and fit in a euro case. I've ended up with a lot of slightly oversized panels so I am just going to build a case purely for DIY. With that, using MOTM power connectors seems the DIY standard. So I've found the headers and connectors to order:
https://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&langId=-1&catalogId=10001&pa=104716&productId=104716
https://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&langId=-1&catalogId=10001&pa=104792&productId=104792

What is the norm for wire? Are you guys using ribbon cable like euro or individual wires or what? What is meant to be used with these connectors? I feel silly asking but I've tried some internet searched without much luck.

Also, is this the crimping tool I need?
https://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&productId=338678&catalogId=10001&storeId=10001&krypto=9x3mj8umRTpQrnRsUchfjCHE4OPYegLYhgoAYeDcJPMJzdA028ux5XpBdIwoq1Z7KTCAZN7CkAMx%0D%0Aje7bv0hJ5erGyUa5ExUt&ddkey=https:StoreCatalogDrillDownView