Solution to some Peavey Amplifier Problems

[Keith Hilton]

Some time back I had a Peavey 112 amplifier that developed numerous problems. I actually thought the amplifier was done for. Everything about the amp was going crazy. I took the amp out of the enclosure to see if there was anything obviously wrong. I could not see anything wrong. Sometime in the past I had heard about the Molex connectors causing problems with Peavey Amps. There were many of these Molex connectors, maybe 8 or more. The Molex connectors have metal male and female connection parts. I wondered if the metal had deteriorated to the point of losing good connection in places. I decided to unplug and re-plug the Molex connectors several times in an attempt to knock off any corrosion. I did that with all of the Molex connectors, then put the amp back together. The amp was quiet as a church mouse, sounded like a new amp, with zero problems. At that point I wondered about a product they put on wire connections in cars. I bought some of the paste and performed a test. I wanted to see how conductive the paste was before putting it on the Molex connectors, so I put a ohm meter in the paste and moved the probes close together. I could not establish any conductivity in the paste. That scared me so I decided not to use the paste.
Fast forward about 6 years. I came across a product called Penetrox A, made by Burndy. It is a electrical joint compound for all bare AL/AL and AL/CU connections. For the prevention of oxide build-up. A conductor termination compound. It says--"Good for all voltages". It also says, "Assures a high conductivity joint by sealing out air and moisture to prevent corrosion and reformation of oxide film." Actually sounds wonderful.
I am wondering if anyone has had experience using this product? In the past I was most concerned that the voltages in the Molex connections was really low, thus a paste might actually prevent the connections from working. From what I read on the bottle it sounds like this product is something that might solve the Molex problem. I think the product is designed for Aluminum to Copper connections. The question them becomes, "Will this product work on the metal in the Molex connectors?

[Jerry Overstreet]

Interesting question and observation.

In the automotive repair industy, we used a product called dielectric grease on light bulbs and many electrical connections throughout the vehicle such as high voltage ignition parts etc.

Its purpose is to protect the connection from moisture, dirt etc. and corrosion between the mating parts. I don't know about conductivity, but I don't think they would be recommending it if it interfered with the connection.

I don't know if this product is something like you refer to since it's designed for automotive electrical which are DC systems for the most part but some probably convert to AC current these days.

[Larry Dering]

Keith, I have no experience with that product but I have seen an antioxidant used on electric meter connections by the power company. I was having some issues with my Peavey Bandit and like yours cleaning and reseating the connections solved it. I used Craigs spray contact cleaner and I scrubbed the pins with a brass bristle brush.

[John Ducsai]

I have used Penetrox for decades in the Electric Utility industry for connections. I have also used it for automotive and marine connections. It works - don't get it on your clothes

[Bill A. Moore]

I believe the ingredients are Hydrogen Peroxide and another peroxide. I worked for a power company in the 80's, and they used Penetrox that came in grease gun style cartridges. My in laws had an old mobile with aluminum wiring that was causing problems, I replaced the fixtures with CU/AL and penetroxed all the connections. 20+ years later we got rid of the trailer, with no electrical problems!
The "dielectric grease" is a silicone based product, non conductive, but also seals the connection from outside contaminents.

[Donny Hinson]

Keith, electrical lubricants and greases cannot be conductive. If they were, they would cause short circuits, or possible heating effects from the currents present. Instead, they are usually just silicone-based dielectric lubricants, and the best ones may contain a small amount of cleaning and anti-corrosion compounds. The cleaners clean, the anti-corrosion compounds neutralize, and the silicone coats the conductive elements to keep oxygen and water out to prevent corrosion, usually caused by electrolysis.

I’ve always found that the Molex connectors work great in computers and a few other stationary applications. But they don’t work as great in portable amplifiers or other equipment that is subject to vibration, bouncing around, contaminated air, and the high-humidity that instrument amps often are exposed to.

[Jim Sliff]

Regardless of the connector (or variable resistor) type you should never use "contact cleaner" alone.

In potentiometers and faders cleaner removes the oils needed for corrosion resistance on the contacts. and on static connectors like tube sockets, ribbon cables, molex types etc cleaner will leave the surfaces bone dry and unprotected.

So they need cleaner/lubricant as well. I find that connectors with nagging problems have usually been subjected to contact cleaner - they can be fixed...usually...by use of cleaner/lubricant. But some become so pitted replacement is required.

Pots and faders that have just been "cleaned" are destroyed fairly quickly - by abrasion if moved, and by pitting if left in one setting.