Topic: CA9100 left input mini XLR problem

[lpmaskman]

I encountered in problem with my CA9100, it seems like the left input has some contact issues, like in somepositions it works but not in another. As I move the miniXLR plug, it loses contact, or sometimes it just works in a position, and moving makes loss of contact.

What would be the problem? How it can be solved?

[goodcooker]

There's a couple of ways to track down your issue.

If you have another piece of gear with the same connectors plug it in and see if the problem persists - if it does the issue is in the mic plug not the preamp jack. Open up the connector and see if there's a broken or weakened solder joint where your cable meets the connector pins or a damaged cable.

Otherwise open up the preamp and see if the jacks have any of the same problems - weak solder joints, corrosion, etc. Make sure the panel ,ount jack is securely fastened to the housing - these use a system of lock washers to seat themselves in the housing panel.

Not sure if Chris is even doing repairs on these anymore - and since you are in Europe it may be cost prohibitive to ship it to Canada for repairs anyway.

If you can identify the issue you may be able to get a guitar/music shop or instrument repair tech to get you fixed up. Soldering the these connectors is a little challenging due to their small size but it's not really that hard if you have any amount of soldering experience. If the problem is in the plug (the mic termination) and not the jack (the preamp input) it's probably best to hack off the old connectors and start over with new ones.
TA3 connectors are pretty inexpensive and widely available.

[lpmaskman]

I tried it with switching mics and looks like the problem is on the preamp side. Gonna open the case soon. Also feels like input jack is moving a bit inside.

[capnhook]

I tried it with switching mics and looks like the problem is on the preamp side. Gonna open the case soon. Also feels like input jack is moving a bit inside.

Don't let the smoke out...

[lpmaskman]

Well, I disassambled it. Looks like eveything is covered in resin like material. A little tear can be seen below the connector and it moves as I touch it.

[voltronic]

I can't understand what the purpose of all that epoxy and hot glue is, other than to make this thing very difficult to repair. What a mess.

Maybe you can use a pair of pliers, tile nippers, or wire cutters to remove the epoxy from the broken connector so that you can replace it or repair the bad connection.

[lpmaskman]

For another option for me is building a simple, little battery box for those mics. 99.9% of time I record loud metal music so I don't need amplification most of the time. However this preamp is very old, bought it from a taper friend with a pair of mics a few years ago for cheap, who didn't use it for years, it was laying in his dawer, and bought it second hand 10+ years ago.  So I don't lost too much if I leave it alone and build a simple 3 wire BB, I just need a good schematics.

[DavidPuddy]

For another option for me is building a simple, little battery box for those mics. 99.9% of time I record loud metal music so I don't need amplification most of the time. However this preamp is very old, bought it from a taper friend with a pair of mics a few years ago for cheap, who didn't use it for years, it was laying in his dawer, and bought it second hand 10+ years ago.  So I don't lost too much if I leave it alone and build a simple 3 wire BB, I just need a good schematics.

https://forums.sonyinsider.com/topic/14343-how-to-build-a-stereo-microphone-and-battery-box/

I built the one detailed in this thread and it works just fine with my MKE2 mics. It can be as fancy as you want to make it.

[Gutbucket]

Try cleaning the contacts well first with 90% Isopropyl/contact-cleaner/De-Oxit.

If that doesn't do it, it looks like the jack could be replaced without much problem.  Yeah the solder-joints on the jack are covered with epoxy but the wires leading to it appear to have sufficient length to be able to be cut and reattached to a new jack.

[lpmaskman]

For another option for me is building a simple, little battery box for those mics. 99.9% of time I record loud metal music so I don't need amplification most of the time. However this preamp is very old, bought it from a taper friend with a pair of mics a few years ago for cheap, who didn't use it for years, it was laying in his dawer, and bought it second hand 10+ years ago.  So I don't lost too much if I leave it alone and build a simple 3 wire BB, I just need a good schematics.

https://forums.sonyinsider.com/topic/14343-how-to-build-a-stereo-microphone-and-battery-box/

I built the one detailed in this thread and it works just fine with my MKE2 mics. It can be as fancy as you want to make it.

Thanks! I found a good old thread about the simple 3 wire battery box and I ordered the parts for it.
https://taperssection.com/index.php?topic=49909.0

[lpmaskman]

Try cleaning the contacts well first with 90% Isopropyl/contact-cleaner/De-Oxit.

If that doesn't do it, it looks like the jack could be replaced without much problem.  Yeah the solder-joints on the jack are covered with epoxy but the wires leading to it appear to have sufficient length to be able to be cut and reattached to a new jack.

I ordered mini XLR connectors and let me see how I can change it. First I need to remove the epoxy but how? Will heating it can solve?



2nd note, I built the battery box this weekend, sounds promising, gonna try it live soon! So much lightening for my rig when amp not needed.

[Gutbucket]

Heating is not likely to effect the epoxy, but is likely to melt the plastic housing, and damage the components if extensive enough.  I'd cut the wires as close to the jack as possible, label them so as not to mix them up, and cut/grind away the epoxy to free up sufficient space around the hole in the housing for insertion of the new jack.

[lpmaskman]

Well, since that I cut the epoxy out with a pocket knife by pieces, now the solderings looks accessible.

[Gutbucket]

Even better

[lpmaskman]

I replaced the mXLR input without problems, but looks like there is another problem, with its cable, but thankfully it has another output, a jack female, and it works with that.