Connect Corner: MASS (Appeal) Connectors
The story of how an industry icon came to be and
has adapted through the years
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While they’ve become one of the most popular and recognized multipin
connectors in pro audio, the back-story of how MASS connectors came
to have such impact shouldn’t be overlooked. |
There, a composite picture of the underlying geological structures could
be determined and analyzed for the prospect of containing oil deposits.
It was the connecting of these cables that necessitated a large contact
count connector.
The characteristics that this connector possessed in oil exploration also
made it ideal for multi-channel audio:
• Rugged and able to withstand many connection cycles.
• Resist the elements as it would be outdoors and often laying on the ground exposed to dirt, sun and rain.
• Hermaphroditic (asexual, genderless) so that any connector could be mated to any other. This eliminated the need to keep track of the usual malefemale connector configuration. (Imagine laying out a mile of cable only to find that you’re holding onto the wrong end!)
• Many pins and sockets, 88 each for a total of 176 contacts.
UNIQUE FACTORS
While Whirlwind wasn’t the first company to bring MASS connectors to market,
they’ve contributed significantly to their proliferation in audio applications.
Back in the late 1970s, several providers began using multipin connectors
as a means to provide disconnects for faster and easier setup and teardown.
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Whirlwind, already producing the Medusa snakes and getting into
microphone splitters, saw the addition of multipin disconnects was
a logical addition. Several multipin connector systems were used,
but in the early 1980s, a connector produced at the time by ITT/Cannon
had some unique features that gave it the edge. |
The Cannon MASS connector became Whirlwind’s standard in 1986, called
the W4. A smaller connector was also available with 122 contacts and that
was added to the mix a short time later as the W3.
MASS Connectors rapidly became accepted in the industry due to their reliability,
capacity to handle a large number of channels and because they were offered
as the standard disconnect by Whirlwind, already a dominant player in
this field. However, a few years after the adoption of MASS connectors,
the technique used to explore for oil began to change. Satellite imaging
was proving to be an accurate and less expensive method of mapping geological
structures and began replacing the dynamite/seismograph approach. ITT/Cannon
cut back on production but connectors were still available.
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And then the unthinkable happened. During transport at the Cannon factory, the tooling for the W4 was dropped from a forklift, causing damage beyond repair. Cannon believed that re-tooling wasn’t worth the effort due to
the reduction in demand for the connector and the existing supply
was deemed sufficient to last until the connector’s usefulness had
expired. That door slammed shut and in 1989, Cannon abandoned its
multipin connectors. |
DECISION TIME
Numerous sound companies had invested heavily in the W3 and W4, adopting
it as a standard. As a result, MASS systems were available in most locations,
making it very easy for touring groups to borrow or rent cables and fan-outs
for an emergency replacement or to extend a system for a particular show.
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With the Cannon door firmly closed, Whirlwind ventured to set up
its own large-format connector production facility, a significant
financial risk for a relatively small company. With the original
tooling completely destroyed, the company’s engineering team had
to start from scratch, not only creating the means to produce quality
MASS connectors, but ones that would be compatible with the thousands
already in use. |
CRIMP IN THE PLAN
Up to that time, all MASS connectors were solder type, making them difficult
(if not impossible) for the average installer to assemble in the field.
For this reason, designers were hesitant to specify MASS connectors into
installations. Also, if a pin happened to become bent or broken, the entire
connector would have to be cut off and a new one soldered on. (There are
stories of a few hardy souls that have replaced a solder type pin by prying
the face of the connector insert away and disassembling it. Then they
reassemble the whole thing pin-by-pin and socket-by-socket all 176 contacts.
Do not try this at home!)
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This led Whirlwind to the development of a replaceable contact
version, necessary if the MASS connector was to be accepted for
installs like stadiums, theaters, theme parks and the like. It was
a challenging process the solder connector was a known quantity.
But a replaceable contact version would have to be compatible with
the “mass of MASS” connectors already in use. |
Whirlwind engineers decided that the insert would be made of a three-piece assembly. The front piece was made of rubber and provided the face to the connector. The rear would be a solid wafer containing metal clips to hold the pins and sockets. Since the metal clips would hold the contacts, the front rubber face would not expand as it was loaded. A center wafer was sandwiched between the front connector face and the rear wafer to keep the contacts aligned.
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Contacts would be inserted and extracted through the rear wafer. All three pieces were housed in a machined aluminum shell and held in place with a “C” clip. Special pins and sockets were designed with a small cup on the rear into which the wire was placed and crimped with a standard hand-crimping tool. The contacts could then be pushed into the insert from the rear until they clicked into position. If it became necessary to remove a pin or socket, a small tube like extraction tool was designed to be inserted around the contact and up into the connector shell where it pushed back the metal fingers on the retaining clip, allowing the contact to be pulled back out. |
THE BEST LAID PLANS
The first run of about 100 W4RP (replaceable pin) connectors were readied
for the rigors of the field... Or maybe not. It quickly became obvious
that the design needed work. Out of those first 100 W4s, quite a few experienced
problems with the pins and sockets not holding in the insert, so they
were immediately recalled for analysis.
The retaining clips weren’t holding in the wafer solidly enough. The
original design called for some “slop” in how the pins were secured side
to side. The feeling was that they should be free to align themselves
when entering the socket. However, the pins had enough movement that they
would occasionally miss the socket opening entirely and hang up on the
rubber face of the opposite connector. Then the mating force would cause
the clip to push out.
The design was totally re-thought and resulted in these solutions:
• Elimination of the “play” the pins had when secured in the insert.
• Slight softening the material that the clips were contained in, while increasing the shoulder size for retaining the clip. This caused each clip to have positive “bite” in the wafer.
• Redesign of the shape of the pin to round its profile. This made them less sharp and provided more positive entry into the socket. The rubber face of the insert was also hardened so that if a pin touched the opposite face, the pin would deflect down into the socket and be less likely to stick in the rubber.
• Creation of a cone-shaped opening into the socket, also to help direct the pin down into the socket.
• Addition of an extra metal thickness to the shell receptacle area surrounding the insert to eliminate the ability to try and mate the connectors at an angle. Now, the opposite rubber “locator” must fit straight down into the narrow receptacle on the opposite face.
Clip failures virtually disappeared overnight. In fact, the improvements
were so dramatic that all of the new features were incorporated (except
of course for the clips) into the solder-type MASS.
MASS GOES MICRO
Up until 1998, Whirlwind’s small-size multipins were the mil-spec W1 (39
pin) and W2 (61 pin). These are still available from a few manufacturers
today. However, the pin counts don’t fall into “normal” channel configurations
seen in audio systems.
In 1998, the company moved forward on production of the first multipin
connectors designed specifically for audio professionals. This connector
would have all the features required for audio systems the same “sexless”
design found in the MASS connector, and that there would be two sizes,
one with 48 contacts and one with 84 contacts.
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48 contacts would handle up to 16 channels and be suitable for
use as subsnakes or with small mixers. Also, 84 contacts would handle
up to 28 channels and be good for use as subsnakes and 24 channel
console snakes with four returns. These connectors could also have reduced density of pins and sockets,
making the design considerations a bit easier than the large MASS
connectors. The new W5 (48-pin) and W6 (84-pin) MicroMASS connectors
were brought to market in early 1999 and have become a new standard
for smaller snake systems and subsnakes. They are only made in replaceable
pin versions and the design has proven highly durable. |
One unusual issue came up during the design. These connectors are exactly the same size, made that way on purpose so that they can share common parts. However, it could be possible for someone to take a W6 and try to plug it into a W5 if they weren’t paying strict attention. The solution was adding a “key” to the W6 connector face to eliminate the possibility of getting one type inserted into the other. Also, it was decided that the W6 insert be changed to white and its locking ring to blue so the W5 and W6 would be easier to identify when systems contained cables of both types.
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FUTURE SCOPE |
(Live Sound will be featuring an in-depth report on the DLS1 system in an upcoming issue.)
Al Keltz is director of marketing for Whirlwind and can be reached at alk@whirlwindusa.com
June 2003 Live Sound International