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.
Be prepared: All good “Cable Scouts” keep these tools handy when working with MASS connectors.
The design was totally re-thought and resulted in these solutions:
- Elimination of the “play” the pins had when secured in
- 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
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.
Choose your weapon.
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.
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.
State-of-the-art MASS connectors, the result of years of evolutionary improvement.
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.
While new methods of audio transmission, digital and otherwise, have made and will continue to make significant impacts on the way in which live sound is distributed, it’s valuable to have an understanding of where we’ve come from, and the MASS connector is clearly a part of that story.
Al Keltz is director of marketing for Whirlwind