Application Note 5 - RTS and Dual Patch Bays
- The jack fields used in most broadcast and studio consoles employ a variation on a connector
developed originally for telephone switchboards. The main feature of these that has kept the
design active has been the amount of switching that can be hung-on the jack, permitting very
involved interrupt or bridging variations to take place upon the insertion of the plug.
However, by its very nature, the sleeve contact does not always make a good connection, and while this contact is used for the shield, and the other contacts maintain the balanced line conditions in most applications, even the presence of rectifying films in a shield circuit can cause problems with RFI.
Good contact is of course necessary in the signal path, when it is not made, there can be problems with poor signal to noise ratio, microphonics, RFI, and even distortion are present.
- Existing solutions:
- The treatments previously available fall into three general classes; cleaners, protective oils, and
contact-plating-material stabilizers. Most cleaners are based on solvents such as perchloroethylene,
or one of the Cellosolveves(TM), either singly or in combination. The protective oils range from
silicones through vegetable oils. The third class would be a material like poly-phenyl-ether or
something similar. A possible fourth class could the combination of any of the others,
including a possible solvent.
However a problem often encountered with oils is their tendency to "Varnish" or for a tough film on the surface of the connector. This is especially aggravated by the presence of sulfur from the high sulfur or free machining brass stocks used in the manufacture of many of the jack field contact parts. Quite a number of the vegetable oils (such as palm oil) can be cross-linked (literally vulcanized) by free sulfur, forming a sort of crummy varnish-like deposit in the process.
- The use of Stabilant 22/22A/22E:
- Where varnishing has been experienced it is important to clean off any such deposit from the
connector before applying Stabilant 22/22A/22E. We would suggest the use of any of
the cleaners which do not contain silicone or oil of any other kind.
By then applying a thin coating of either Stabilant 22, Stabilant 22A or Stabilant 22E, to the ring tip, & sleeve contacts (or to the tip and sleeve contacts of the 2 circuit plugs) and only will the signal to noise ratio be improved, but harmonic distortion can be reduced as well.Be sure to apply Stabilant 22/22A/22E to the switching connections in the jack field as well. The use of one of the proprietary cleaner/applicators such as the burnishers made by Vertigo Recording Services is advisedl**
- Results that are to be expected:
- It is suggested that only one channel be treated initially and compared with an untreated channel. The difference us usually audible as a smoother more musical sound on the treated channel.
- Reference is made to Technical Note Number 24 -
"Effects of Stabilant 22 on Harmonic Distortion in Connectors"
**Vertigo Recording Services 12115 Magnolia Blvd. North Hollywood, Ca 91607, USA
Stabilants™ are a product of Dayton Wright research & development and are made in Canada
NATO Supply Code 38948
15 ml of S22A has NATO Part # 5999-21-900-6937