mic cable repair help

[Peter Lowe]

Hello, I have a Sennheiser MKE300 microphone and can see the cable is about to break right where it meets the microphone, which I think is called the strain relief, but it hasn´t broken yet and the microphone still works fine. However the protective outer sleeve is worn right through and I can see the inner wires are starting to fray. This is not good. The cable is moulded to the back end of the mic. What I would like to do is figure out some way to reinforce the cable so it does not break but not sure what would be the best way to do this?

[Donald McPherson]

Carefully open it up and re-solder it. Get an old push button pen. You know the one's I mean. Take the spring out of it and slide it on before you solder. Once soldered slide the spring hard up to the mic and fix with a spot of glue.

[Peter Lowe]

Thanks Donald, even I can see how the pen end would work as strain relief and bump protection once I got that far. I think I can take apart the housing at the back end of the MKE300 and get the cable out and also find someone to help me reconnect the wires since they are quite tiny so I am not expert or confident enough to try myself.

If the wires are removed then reattached as you suggest is there any risk of noise if they are not soldered back on properly or is it just either it works or it doesn´t. The reason I ask is even though the cable is quite fragile at the moment the mic still works as it should so I would not want to make it worse if there was a risk of that happening due to faulty workmanship.

[Paul R Johnson]

If you simply can't open up the mic to fix it properly, then you need a bodge that won't impact on the ability for somebody else to do a proper repair if you sell it.

At some point the cable will break - that is a given. A broken cable is fixable - eventually.

The bodge is to make sure the thing can't break. A single turn of lx tape on the rear, then mix up some epoxy, and cover the tape and the entire cable relief and the cable itself with a thin coat of the epoxy. Repeat, and repeat as it dries to build up a tough hard layer that won't allow the cable to move and bend/snap. This will easily keep the cable intact and usable. Looks a bit naff, but there are ways to cosmetically make it look better. When the final layer of epoxy is still soft, wrap the thing in ordinary white string, neatly winding it on. When it's dry, colour it in with a sharpie! Looks fine then. When you go to sell it, with a broken cable - simply pull the entire thing off, as the wrap of LX tape prevents the bodge adhering to the mic, just the tape - so pulls off, breaking the wire at the weak point. Then you can sell it as good condition with broken cable, and somebody who can solder can buy it and fix it.

[Peter Lowe]

Meanwhile I have found another totally unrelated issue that is also confusing me quite a bit:

I have an old Beachtek DXA-4P Dual XLR Universal Microphone Adapter that I just got out of the back of my wardrobe to try out with the Sennheiser microphone I mention above on my A7II. Much to my surprise it works - but emits a continuous low hum that I hear in my head phones when I plug it into the camera, so for some reason even though it is a passive adapter with no battery it wants to hum.

Maybe it is too old and for some reason not compatible with modern cameras? Perhaps this ought to be a different thread so hope it is ok to raise this here even though it is not related to the question in my first post in this thread?

[Peter Lowe]

Originally Posted by Paul R Johnson

If you simply can't open up the mic to fix it properly, then you need a bodge that won't impact on the ability for somebody else to do a proper repair if you sell it.

At some point the cable will break - that is a given. A broken cable is fixable - eventually.

The bodge is to make sure the thing can't break. A single turn of lx tape on the rear, then mix up some epoxy, and cover the tape and the entire cable relief and the cable itself with a thin coat of the epoxy. Repeat, and repeat as it dries to build up a tough hard layer that won't allow the cable to move and bend/snap. This will easily keep the cable intact and usable. Looks a bit naff, but there are ways to cosmetically make it look better. When the final layer of epoxy is still soft, wrap the thing in ordinary white string, neatly winding it on. When it's dry, colour it in with a sharpie! Looks fine then. When you go to sell it, with a broken cable - simply pull the entire thing off, as the wrap of LX tape prevents the bodge adhering to the mic, just the tape - so pulls off, breaking the wire at the weak point. Then you can sell it as good condition with broken cable, and somebody who can solder can buy it and fix it.

Perfect! Exactly what I need - a bodge (-:!!

Thanks also for the detailed description of how to do it that even I can understand!

I don´t mind at all what it looks like as I am not working with art directors or brides...

Meanwhile I have just found out Sennheiser used to manufacture a replacement cable for the MKE300 that is a bit unusual (perhaps because due to the design many others had the same problem that I have run into) so that could be a more permanent solution a bit further down the track.

Meanwhile I have a project coming up and the only place I have been able to find the replacement cable so far are two suppliers one in the UK and another one in the US who do not ship overseas, so I will try a bodge.

[Jay Massengill]

Back in the day when the Beachtek DXA-4P was a common item, the user manual came with a note saying that Sony cameras had a different ground scheme on their mic inputs and the model Beachtek DXA-4S was designed to ground properly with Sony cameras and prevent noise.
Maybe that's still an issue?

[Richard Crowley]

It depends on whether the strain-relief is MOULDED onto the cable, or whether the cable passes through the strain-relief piece. It is iimpossible to tell from looking at the photos.

If the cable passes through the strain-relief which is a separate piece, then the usual repair is to pull the cable "in" beyond the broken part and re-solder it into the internal terminals. Yes, this requires some rather delicate wire stripping and soldering. Perhaps not a task for the inexperienced.

If the strain-relief is molded onto the cable, then you have much more limited solutions. One of my favorites is a product called Sugru. It is available from several places online including Amazon:
https://smile.amazon.com/Sugru-Molda.../dp/B01BFE0KNQ

It is very easy to apply and results in a decent-looking and very robust repair. Recommended.

Here is just one of many YouTube videos showing how to accomplish a repair like your situation:

YouTube (Short URL)

[Peter Lowe]

Originally Posted by Jay Massengill

Back in the day when the Beachtek DXA-4P was a common item, the user manual came with a note saying that Sony cameras had a different ground scheme on their mic inputs and the model Beachtek DXA-4S was designed to ground properly with Sony cameras and prevent noise.
Maybe that's still an issue?

Thanks for raising this point that encouraged me to take direct contact with Beachtek via their support page quite late last night. Imagine my great surprise when I found a detailed reply from Beachtek support waiting in my email when I got up today Sunday morning. Wow! I was very grateful, even though the news was not good. Harry from Beachtek politely but firmly informed me what I should have realized myself that it was not a good idea to try to use an old adapter on a new camera.

In a nutshell: the "long since discontinued DXA-4P" was "only designed for use with the Canon GL1 or GL2 camcorders. It does not have the proper grounding configuration which is causing the hum on your Sony A7II. It also does not have any preamps..."

So I just bought a new Beachtek dxa-micro-pro adapter and expect to sleep a little better tonight:-)

[Peter Lowe]

Originally Posted by Richard Crowley

It depends on whether the strain-relief is MOULDED onto the cable, or whether the cable passes through the strain-relief piece. It is iimpossible to tell from looking at the photos.

If the cable passes through the strain-relief which is a separate piece, then the usual repair is to pull the cable "in" beyond the broken part and re-solder it into the internal terminals. Yes, this requires some rather delicate wire stripping and soldering. Perhaps not a task for the inexperienced.

If the strain-relief is molded onto the cable, then you have much more limited solutions. One of my favorites is a product called Sugru. It is available from several places online including Amazon:
https://smile.amazon.com/Sugru-Molda.../dp/B01BFE0KNQ

It is very easy to apply and results in a decent-looking and very robust repair. Recommended.

Here is just one of many YouTube videos showing how to accomplish a repair like your situation:

https://youtu.be/SEQ0fSZJuSk

Now I am confident this can be repaired and will figure out what can be done - much better than having to start looking for a replacement one :-)

[Jim Feeley]

+1 for Sugru