The ins and outs of multipin connector designs
The choices of multipin connectors is wide and varied.
The use of multipin connectors for live touring has become the
norm, not the exception. But trying to make headway through the
myriad of connectors that are used can sometimes cause confusion.
Blame it on Whirlwind! Way back in the “dark ages” of the 1980s,
Whirlwind introduced the concept of multipin connectors by adopting
the 142-pin Cannon Mass connector. This hefty device was developed
in Whitby, Ontario for use by the mining trades in Alberta. It had
the distinct advantage of being hermaphroditic (half male, half
female), allowing long cable lengths to be deployed and extended
as mining pits grew. The rugged circular design and water-resistant
O-ring combined to be well suited for use in harsh environments
such as outdoor festivals.
Several companies currently offer multipin connectors, most of which come
from the military or aerospace industries. These include circular bayonet
connectors, such as those made by Pro Co, Veam, Amphenol and their European
counterparts, and square-block connectors from companies like Edac, Amp,
Cannon and so on.
Making a decision on a multipin often comes down to standardizing the
complete rental department. Often, even though one may not be enamored
with a particular connector, changing over can be cost-prohibitive. Clair
Bros., for example, was an early adopter of using a circular screw-on
multipin connector for smaller snakes. Even though Clair might prefer
changing to some of the newer bayonet-style connectors, it has so many
of the older models that it’s not feasible to make the switch.
The difference in size between Veam (above) and Mass pins.
One of the most challenging decisions lays in selecting larger
channel multipin connectors. For instance, the Mass connector is
one of the most common in use today, and it’s a very good connector.
However, because the Mass (W3 or W4) has very small pins, they are
easily broken. And changing the pins is not for the faint of heart.
The connector must be collapsed by removing a C-ring, and then the
two “pucks” that hold the pins in place must be pulled apart. To
do this, all wires must be removed and all solder cleaned off.
New generations of connectors, such as those pioneered by Veam and now
manufactured by a variety of offshoot companies, allow individual pins
to be removed and replaced. This makes the connector field-serviceable,
and, for many, has been reason enough to switch. There have been attempts
by a couple of companies to make a removable pin version of the Mass connector,
but the diminutive size of the pin and density of the pin block have yielded
varying degrees of success. As a result, when given the choice, most system
designers opt for a larger pin size, which not only reduces opportunity
for damage, but also ensures a greater contact surface area.
WHAT A RELIEF
Another key factor in determining the suitability of a multipin connector
is the strain relief. For example, Edac and Elco make a good connector,
but due to small cable openings and non-existent strain-relief, they are
usually only used in fixed or semi-permanent installations. If absolutely
necessary, a Kellems-style grip can be attached to the cable as a reasonable
Taking apart the mass connector.
For larger multipin connectors, the choice comes down to either
compression fittings or large Kellems grips. Kellems or “Chinese
finger trap” stain-reliefs are generally considered the best options,
however, keep in mind that they do cost significantly more. It’s
a good idea to dab on some Locktite or even insert a locking screw
so that the connector barrel does not loosen after use.Often, untrained
hands will try to disconnect these connectors and turn the wrong
section, which can cause undue strain on the fragile internal solder
Unfortunately, there is no official standard wiring configuration currently
in use on the market. Just because Whirlwind offers a standard pin-out,
some of the major touring companies opt to use their own pin layouts,
thereby making the Whirlwind approach incompatible.
The best guarantee for compatibility still comes down to a spare multipin-to-XLR
panel or cable. Every sound company, recording and broadcasting truck
is able to mate with another XLR. Therefore, it makes a lot of sense to
simply outfit a snake system with a second XLR panel to allow cross-patching
Peter Janis is president and managing director of CableTek Electronics, the parent company of Radial Engineering, Primacoustic and C-TEC. He is also chairman of the Vancouver AES Society.
MONTHYEAR Live Sound International