Patch cable between FX send & return jacks - Cheap Insurance?

[Jim C]

Just had an unusual thing where the contacts on an Ashdown ABM500 didn't distort but rather just lowered the output volume.
A suggestion from the Ashdown crew on this board suggested a patch cable to test and sure enough all is well.

I'm assuming that the contact patch on these self shorting jacks is about the same amount of surface area as using a cable into the jack contacts.
Maybe the extra spring tension would offer a better long term contact?

Sems that most compressors / effects sound a bit better between the intrument and the amp input so not a feature I normally use.

Thoughts?

 

[agedhorse]

I would recommend properly cleaning the normalling contacts with a bit of DeOxit.

 

[Old Garage-Bander]

I wouldn’t think it would be a spring tension problem on the jack. That is more likely with jacks that see a lot of use.
Effects jacks can go unused for years, if ever, which opens the door for oxidation.
Kind of a use it or loose it deal.

Sometimes just inserting plugs will clear the problem.
Better yet, use De-oxit as suggested.
DO NOT spray it into the jack. Rather apply a little to the plug and run the plug in and out a few times.
Keep a short patch cable in the gig bag just in case.

I suggest getting the real deal De-oxit, not some poser substitute.
I’ve tried some of the off brands and they just don’t seem to do the job nearly as well.
I just bought a new can of De-oxit last month. It did the trick on some noisy pots on an amp that the other stuff didn’t begin to touch. $10 well invested, especially for a gigging bass player.

 

[agedhorse]

DeOxit on a plug won't clean the switch

 

[Old Garage-Bander]

DeOxit on a plug won't clean the switch

Yeah! That’s right. It will only get the tip/sleeve contacts.
You pretty much need to take the amp apart and use a burnishing tool or replace the jack.

 

[agedhorse]

A tiny bit of DeOxit on the switch contacts works better than burnishing.

 

[Old Garage-Bander]

A tiny bit of DeOxit on the switch contacts works better than burnishing.

Granted. Especially if someone gets heavy handed with the burnishing tool. Or uses the wrong thing to “burnish” it. And it may depend somewhat on corrosion vs oxidation, or the condition of the contacts.
But how easy is it to just use a spray cleaner without disassembly?

You might be able to direct the stream towards the contact side of the jack if you can see where it is. But just “shotgunning” a lot of De-Oxit spray into the jack in hopes of a little bit hitting the switch contacts doesn’t seem like a good idea either.

If you aren’t skilled at amp disassembly/reassembly, then it could get start getting expensive.
Pay a tech to do the cleaning or jack replacement, or pay him to fix what you might screw up by doing it wrong.

 

[agedhorse]

Agreed, don't go spraying away in hopes of hitting something blindly, that just makes more of a mess.

With a vertical enclosed PCB mount jack, sometimes you have no option but a tiny spray into the jack, but better to avoid if possible.

 

[Jim C]

Thanks and I do only used Deoxit for anything audio; the CRC is reserved for line voltage gear
In my case it will be to remove the amp chaisis from the sleave, and the jacks will be easily accessable

 

[agedhorse]

CRC makes a might fine torch too (note to others, don't try it... I'm just kidding)

 

[BadExample]

CRC makes a might fine torch too (note to others, don't try it... I'm just kidding)

Sometimes you have to...



biz cards make a good and safe burnishing tool.

 

[Real Soon]

Unused contacts will get oxidation on them. Just a fact of physics / environment.

I haven't used DeOxit, but have used rubbing alcohol and a q-tip/cotton swab to clean off an output jack with great results before, and DeOxit just sounds like it'd be even further optimized for the job. In extreme cases like long periods without use + exposure to humidity, a light touch-up with medium-grit sandpaper (150-220, mounted on a small tool if you don't want to open up the instrument or amp) can get built-up oxide off before applying the cleaner.

Also, these metals do get small grooves in them from use. A bit of extra-fine sandpaper on a cable tip that's well-used but otherwise in good shape (and similarly on a well-used but still springy jack) can help smooth out the grooves and restore contact surface area. Most of the time we just replace stuff by then, but if you're averse to tossing metal parts, you don't always have to.


As far as insurance... there's not much. Plugging the jacks doesn't keep moisture out since you've always got a little air & moisture getting in from other jacks, heat dispersion vents, etc, and keeping a patch cable in there can help but does introduce a small amount of strain to the jack's metal, possibly making it less springy and more iffy if left that way for a long time. These things just need maintenance, y'know?

 

[agedhorse]

Never ever use sand paper on electronic contacts. That's the sigle quickest way to ruin a connector. Nothing good can come of this in the long run.

Electronic connectors are plated and nothing should be done to damage or remove this plating.

 

[Jim C]

Agreed, safe burnishing only works on solid copper, brass, or bronze.

 

[Old Garage-Bander]

I would think that if a patch cable solves the problem, and there is no other good solution short of paying a tech to clean or replace the jacks, then leaving the patch cable in would be OK.

 

[JimmyM]

I've cleaned them out by sticking a plug in and out of the jack many times really quickly. Is not as good as the Deoxit cleaning since that'll be longer lasting but it does work.

 

[agedhorse]

I've cleaned them out by sticking a plug in and out of the jack many times really quickly. Is not as good as the Deoxit cleaning since that'll be longer lasting but it does work.

And is safer than sand paper (or an angle grinder )

 

[beans-on-toast]

It takes some time for a jack shunt to oxidize. Use deoxit once every year or two. Often people whose amps have oxidization issues haven’t been serviced in years.

Between maintenance sessions, it helps to exorcise the jacks by cycling a plug in and out of all jacks that haven’t been used often. This can be the case with effect loop in and out, preamp out, power amp in, slave out, and footswitch jacks.