Application Note 15 - Stereo Systems
- What is Stabilant 22?
- Stabilant 22 is an initially non-conductive block polymer which when used in a thin film
between metal contacts becomes conductive under the effect of an electrical field. This occurs
at an electric field gradient such that the material will remain non-conductive between adjacent
contacts in a multiple pin environment. In addition, Stabilant 22 exhibits surfactant action,
as well as lubrication ability providing a single component resident solution to virtually all
When applied to electromechanical contacts, Stabilant 22 can provide the connection reliability of a soldered joint without bonding the contact surfaces.
- What are its benefits in a stereo system?
- In general, Stabilant 22 can be used wherever electrical contacts are used, whether this is in connectors, or in switches. In home stereo system applications the number of places where Stabilant 22 or 22A can be employed are almost too numerous to list. When the signal path connectors and switches in an entire stereo system as treated (including socketed ICs and card-edge connectors) the distortion and signal to noise performance are usually improved substantially.
- Where and how do I apply Stabilant 22?
- Phono Cartridges: As the Stabilants reduce distortion caused by thin film rectification effects and as this effect is
most pronounced at very low signal levels, the application of Stabilant 22A should start with the phono cartridge pins.
With Stabilant 22A it is not necessary to disconnect the phono cartridge leads as the diluted material will penetrate the connections. Use only a small drop on each cartridge connection. If the tip of the dropper bottle is too large, use a toothpick to transfer a smaller drop of the material to the contact. Do not use an excess amount! Don't get the material on any of the rubber shields (if present) that may cover the base of the stylus cantilever as the material will hold dust that might be present on the record surface.
PHONO ARM CONTACTS: Audiophiles often forget to treat both the headshell-to-arm connector contacts (if the headshell is detachable) and/or the connector(s) that may connect the cables to the arm. As Stabilant 22A will not cause leakage or bridging between adjacent contacts there is less restriction on the amount that can be used. If "RCA-type" connectors are used, be sure that the outer ground shell is bent inward so that it makes a tight contact to the ground section of the chassis mounted connector half. Stabilant 22A should be applied to both the central pin (signal) and the inside of the outer (ground) connection.
CD CABLE CONNECTORS: If a CD is installed, the connectors on the CD player should be treated with Stabilant 22. Note that it should NOT be used on "light-pipe" type connectors.
PREAMPLIFIER SWITCH TREATMENT: Audiophiles often overlook the fact that preamplifiers have switches in the signal path. These switches are also a potential source of distortion and noise. Rotary switches are usually the easiest to treat although it may be necessary to use a toothpick to transfer a drop of Stabilant 22A from the dropper bottle to the switch contacts. Slide switches may be treated by placing several drops in one end of the switch and cycling the switch.
Push button type switches, especially the ITT-Schadow type, may contain a lubricant that must be removed before Stabilant 22A is used. We have found that if the switch is flushed out with isopropanol (isopropyl alcohol) or one of the proprietary contact cleaners, it does not have to be disassembled. Several drops of Stabilant 22A should be run into the switch body through the slot on the upper side (ITT Schadow type).
We do not recommend the use of Stabilant 22A on volume or balance controls unless they are of the plastic element, wirewound of stepped-metal-contact type. Some controls use a resistive lacquer silk-screened on a phenolic insert for the element and in a few cases, the lacquer can be softened by an excess of isopropanol. ALWAYS TEST THESE CONTROLS FIRST! These might be cheap volume controls, although they are rarely found of good quality equipment anymore, they are much more common in old equipment. On plastic-element controls only the concentrate, Stabilant 22, cut 8:1 with hot water, should be used and then only sparingly. Very little is needed! Don't use the isopropyl- alcohol-diluted Stabilant 22A as the plasticizer in the plastic element can be extracted roughening the control's wiped surface.
POWER AMPLIFIERS: In tube type equipment, the tube pins may be treated individually. Because the voltages encountered in tube-type power amplifiers are often well above the switch-over-field-strength voltages for Stabilant 22 we specifically caution against the indiscriminate use of the material on an entire tube socket. Treat on the individual tube pins!
TRANSISTOR-TYPE POWER AMPLIFIERS: The individual pins on the transistors may be treated here, with one precaution:
MAKE SURE THAT ANY SILICONE GREASE THAT HAS BEEN APPLIED TO IMPROVE THE THERMAL-CONTACT BETWEEN THE TRANSISTOR'S MOUNTING-PLATE AND ITS HEAT SINK, DOES NOT GET ON THE PINS OF THE TRANSISTOR!
To repeat, in transistor power amplifiers, the output-transistor pins can be treated as well as the electromechanical contacts to the filter capacitors, any tab-type connectors, as well as any card-edge connectors. It is suggested that you have this done by a qualified service-technician.
DO NOT TREAT ANY POWER SWITCHES THAT SPARK ON OPENING! If a inductive load is present the spark could cause decomposition of the material.
TAPE RECORDERS: Stabilant 22A may be used in tape recorders. If spring contacts are used on the playback and recording heads these should be treated in the same way as the connections on a phono cartridge. Anywhere there are card-edge connections, Stabilant 22A can be used. And it should also be used on any microphone connectors.
In critical Audio work involving long signal runs, Stabilant 22 on the XLR or cable connectors will not only cut noise, but will, in many cases, improve the sound by stopping high-order harmonic distortion caused by thin film rectification effects.
INTERCONNECTION CABLES: The RCA-type connectors on the interconnect cables should be treated, making sure that both the inner pin (signal) and outer shell (ground) of each connector are treated as well. On DIN-type connectors be sure that all the pins are treated.
LOUDSPEAKER CONNECTORS: The loudspeaker connections may be treated with Stabilant 22A, but we suggest that you make sure that you have treated all the low-level signal contacts first! There will be a much greater effect on lower-level connections, and you don't want to run short.
PATCH BAYS: Some elaborate stereo systems use patch-bays to facilitate equipment use. In these patch bays, Stabilant 22A is recommended for both ring, tip, and sleeve plugs and for the dual tip and sleeve plugs as well as for the jacks. Be sure that the plugs themselves are cleaned of any previous oil-like material that might have been used. The reason for this is that it is not uncommon to find that the ring-tip-and-sleeve type connector contacts have been machined from a "free-machining' brass that has a high sulfur content. The presence of sulfur can cause unsaturated oils to "varnish" producing a thin film that is difficult to remove. Unlike most of these "protective oils", Stabilant 22A is chemically stable in the presence of these cross-linking chemicals and therefore, need not be periodically cleaned off and replaced.
There is also a potential problem with cleaners and lubricants containing silicones Under the right circumstances these chemicals can also cross-link producing a thin glassy polyoxysilane film that can be difficult to remove. Nevertheless, for best improvement this film should be removed before using Stabilant 22A. Use several alternating applications of kerosene and isopropyl alcohol to remove all the silicone!
TUNER, TV, SATELLITE EQUIPMENT AND GENERAL ANTENNAE USE: Stabilant 22 can be used on cable TV connections, on the co-axial connectors used between satellite receivers and the low-noise-amplifier, and on the flange between the low noise-amplifier and the satellite antennae. Stabilant 22A is not waterproof, therefore when using it in areas exposed to rain, we suggest that the connector be protected with a section of shrink tubing, and the antennae waveguide-flange b sealed at its outer circumference, with a double layer of stretched black vinyl tape.
RADIO FREQUENCY INTERFERENCE: RF interference in stereo systems can be a constant problem. With the passage of time, connectors often build up thin films that act as crude rectifiers. This source of RF interference can often be eliminated by using Stabilant 22.
- Why should we use Stabilant over less expensive alternatives?
- Granted that the material itself is expensive, however it is unique in having a very long useful life once in place. Unlike other so-called
contact treatments, Stabilant 22 will not cross-link (becoming varnish-like) under the action of sulfur based curing agents in
elastomers, cutting oil residues, or the sulfur-bearing free-machining metal alloys used in some contacts. In most types of service work,
the cost of the down-time involved in removing and replacing a board will be much greater than the cost of the Stabilant used to treat the
board. Here what is important is that not only will the proper board treatment cure existing contact problems, it will prevent others from
occurring, thus eliminating the necessity of repeating the treatment at a later date!
In other words, why do a job more than once?
- In what forms is Stabilant available?
- The Stabilants are available in several forms. As a concentrate (Stabilant 22), an isopropyl
alcohol-diluted form (Stabilant 22A), and an ethyl alcohol diluted form (Stabilant 22E).
For example, a given size container of Stabilant 22A will cost about one-fifth the amount of a
container of Stabilant 22 as it contains only one-fifth the amount of the concentrate. Another form
of packaging is available. Stabilant 22S packages the concentrate such that it occupies one-fifth the
volume of an otherwise empty container. This allows the end-user to add his own diluent, and thus saves the
added costs of shipping the diluent (e.g.: isopropyl alcohol), as well as allowing the end-user to use an
alternate diluent such as one of the Freon-based solvents.
In addition a 0.5 ml vial of Stabilant 22A is available for manufacturers to include with plug-in circuit boards
- What is the difference in use of these materials?
- Stabilant 22 is most useful where the connections are out in the open - such as card-edge connectors or where the lubricating properties of the material are useful -such as an aid to installing microprocessor IC's or on switches. Where the connections are not too easy to get at or where the user wishes to apply the material to something such as a socketed IC (without removing the IC from its socket), it is easier to use the alcohol diluted form (Stabilant 22A or Stabilant 22E). The alcohol diluent serves ONLY to carry the concentrate into the connector.
- Is it available in a spray can?
- No. Why waste the material? We would like to think we are environmentally responsible and safety conscious. This ruled out
the use of either a chlorofluorocarbon or highly inflammable mixture of butane and propane as a propellant.
In addition even Stabilant 22A for example, has only about 71200th the solvent impact as conventional contact cleaning solvents, over a three year time span. As Stabilant 22 contains no solvent it has absolutely minimal environmental impact and is, therefore, becoming the treatment of choice for many service organizations!
- Is Stabilant 22 just another contact cleaner?
- No, Stabilant 22 is a resident potentially electrically active material which through a synergistic combination of effects enhances conductivity within a contact without causing leakage between adjacent contacts. Thus large quantities of the material do not have to be "hosed" on, as is the case with cleaners.
- Just how much should be used?
- Normally, a final film thickness of from 0.5 to 2 mils of the concentrate is all that it necessary. In other
words, you want just enough to fill up the interstices between the contact's faces. When using Stabilant 22A,
or Stabilant 22E, use enough so that once the isopropyl alcohol (or ethyl alcohol), evaporates the desired
0.5 to 2 mil film of Stabilant 22 remains.
In applications to moving surfaces, such as in slip-rings or potentiometers, film thickness should be minimized to the point where "hydroplaning" won't occur.
- How can I be sure that Stabilant works?
- The best way to find out just how well it works is to try it out; that's why we have samples available. Almost every service shop or manufacturer has equipment available where the switches or connectors have become erratic over the years. Use Stabilant 22/22A/22E on them and satisfy yourself. A word of caution. Don't try to evaluate Stabilant 22's performance on brand new connectors. Instead, use it on connectors that are corroded, or dirty or just plain unreliable. We are sure that any organization dealing with electronics will have at least one piece of unreliable equipment on which the Stabilants can be tested!
- Can I use Stabilant 22 in other equipment?
- Yes, it can be used in test equipment, cameras, just about everywhere there's a low-voltage signal or control connection. For example,
the effect of Stabilant 22 in Computers is to reduce the number of times the system locks-up or crashes, sometimes it even
eliminates non-software crashes completely.
When used on socketed IC's, photo-couplers/isolators, rotary, push button, or slide switches, or even on BNC connectors, the net effect is usually to make the proper operation of the equipment less erratic, and in the case of IEEE-488A buss- controlled equipment, to cut down on the potential for system lock-ups.
- Is Stabilant hazardous to use?
- Stabilants have very low oral toxicity. Under normal workplace conditions no skin sensitization effects have been noted. In the undiluted form, it is non-flammable although if heated above 200° Celsius the decomposition products would burn. And Stabilants are environmentally friendly materials.
- Will the Stabilants cause damage to the equipment?
- No. These materials have been extensively tested for compatibility with circuit-board materials, conformal coatings, as well as with the various plastics and elastomer encountered in electronics. That's not to say that there is no chance that somewhere, someone may be able to devise a cheap plastic material that might show susceptibility to degradation from the Stabliants, but because of all the solvent compatibility requirements that are in place in the industry, it is doubtful if this would ever be used in any commercial quality electronic equipment.
- Does the action of Stabilant deteriorate with age?
- In some field trial applications lasting over fifteen years Stabilant 22 has shown no sign of reduced effectiveness. With a high molecular weight and a very low vapor pressure, little is lost by evaporation. Unlike some other contact protection oils, Stabilant 22 will not cross-link when exposed to free machining materials such as high sulfur brass, or when used on contacts where agents used to promote cross linking of thermosets or elastomers are present in the environment or in the actual connector components. Unlike non-saturated oils, Stabilant 22 does not "varnish".
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