Mic body modification from USB to XLR?

[rock soderstrom]

Wow, no doubt you are Mr. Wulf! I'm still on my way, I'll be in touch soon! Very impressive!

 

[telewulf]

Hua Hua Hua!
Thanx for the comaparison

 

[Khron]

send me your end bits over to Bremen.

This part sounds SO wrong though...

 

[Drosselmeier]

 

[rock soderstrom]

... jepp, worx ...

Very good work Wolf! Thank you for your generous offer, I got a second similar offer from another member. That really surprised me in a very positive way, thanks guys!

On the subject:

I took a closer look at the whole thing, with a 5-pin XLR it will be difficult because the cut-out for the USB is already too big, you would have to glue it. If you were to drill it out completely, the wall thickness would be very small. take a look at it.

I've decided to leave it as a fixed cable solution, which fits very well with the upcycling idea of the two microphones I want to build with the bodies. They get a dedicated dual power supply, one mic is already finished and plays well. I'm going to pour hot glue into the lower part, I'm curious how it will turn out . The whole thing should be in good proportion to the result and the chosen components. It should remain a good sounding low budget project.

To be continued, pics are coming.

 

[rock soderstrom]

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Bravo, now do it with a tube head amp

 

[rock soderstrom]

One mic is almost ready, I am testing several low budget capsules at the moment. Here with my trusty variable B+ PSU.ATM the original capsule is back in the mic to see what it can do with different polarization voltages...

The plan now is to glue the mic flush with gaffa tape at the bottom with the cable centered and then run hot glue in from above. The adhesive should hold the cable permanently in position and also reinforce the strain relief.

I am gonna heat up the glue gun and the experiment will start now.

 

[Drosselmeier]

 

[Harvey Birdman]

The plan now is to glue the mic flush with gaffa tape at the bottom with the cable centered and then run hot glue in from above. The adhesive should hold the cable permanently in position and also reinforce the strain relief.

Hi there, can I suggest using silicone sealant instead of hot glue. My experience is that hot hot glue does not bond well to polished surfaces, especially where movement of the the cable is involved. The disadvantage of silicone is that its bond is so strong, if you had to remove the cable you would probably destroy it in the process.

Whether you use hot glue or silicone, make sure all surfaces are clean and free of anything that may prevent the adhesive from bonding.

I'd also follow Sony's example, post #18, of providing a cable strain relief clamp, if there's somewhere you can attach it to..

Hope this helps.

 

[Tubetec]

If your happy with the wired in cable Id think about using a cable gland for strain relief ,

Find one with the appropriate cable entry diameter and with a thread that fits the square hole in the base of the mic , then use the hand mixed epoxy putty to cement it in place ,
you should then have a professional result , you dont want something spudged up with hot glue thats going to leave you down . .

Good idea to delete the connector at the mic end to save some change especially with a cheap donor body , you also know precisely the effect of the cable , its not like an indeterminate lenght XLR being plugged in .

Perhaps some of the EMC issues seen with XLR plugs at the mic end can also be reduced or eliminated by having a wired in cable .

 

[telewulf]

I took a closer look at the whole thing, with a 5-pin XLR it will be difficult because the cut-out for the USB is already too big, you would have to glue it. If you were to drill it out completely, the wall thickness would be very small. take a look at it.

You´re right, it was a tight fit in my case too. But that´s where the lathe trumps the drill: 1 mm of wall thickness is no problem.



But anyway, now you know who to call for, whenever you need your "end bits" machined ... or any other parts ...
Oh, and by the way: Your "Vary-B+ Supply" looks like a great idea!!!

best regards from Bremen,
Wulf

 

[rock soderstrom]

You´re right, it was a tight fit in my case too. But that´s where the lathe trumps the drill: 1 mm of wall thickness is no problem.

Top job!

But anyway, now you know who to call for, whenever you need your "end bits" machined ... or any other parts ...

Thank you, I really appreciate that!!

Oh, and by the way: Your "Vary-B+ Supply" looks like a great idea!!!

Yes, the Vary PSU is very handy, you can try out a lot of things with it and it serves different requirements very quickly.

 

[rock soderstrom]

My experience is that hot hot glue does not bond well to polished surfaces, especially where movement of the the cable is involved.

then use the hand mixed epoxy putty to cement it in place ,
you should then have a professional result , you dont want something spudged up with hot glue thats going to leave you down . .

Thanks for the good tips. Your concerns have given me food for thought and I started with a few material tests . I tested the usual transparent hot glue, but it was too soft for me.

Then I ordered black hot glue, which carpenters use to fill holes in wood.
It sticks like hell and hardens very well, but is liquid enough to work with (even with my cheap gun).

You can only get it out of the beverage cap with brute force. That definitely fulfills my purposes.

 

[rock soderstrom]

Okay, I completely filled the lower part of the microphone with black hot glue. That was no problem at all and does its job very well. The two cable ties on the summer cable serve as strain relief. This works all the better now that everything is molded into a large plug, which is additionally held in place by the set screw.

It's bombproof and would survive a Roger Daltry stage show, at least as far as the strain relief is concerned.

All in all, a viable option for low budget upcycling these USB mics if you don't have the skills and machines to turn them out.

The only thing I will change on the second mic is a bend protection at the lower exit point for the cable, which I would also glue in.

 

[Tubetec]

Thumbs down from me ,
Thats an attrocity against tube microphones

What happened to German engineering Rock ?
Hot glue is a cheapskate way of doing it ,
A metal cable gland costing a few euros not only provides proper sheilding and continuity to the mic frame ,but in the event of a problem you can easily take things appart without having to dig out chunks of hot glue and make a big shitty mess of it .

It should be possible to tap threads into the hole at the base of the mic to mount up the cable gland ,
I see the type B USB panel cuttaway is 10.5x11.5 mm ,
only basic hand tools are needed ,
a file, to square out the hole , a drill to make it a circle and a tap to cut the threads , job done ,


Wiring in the cable is something Ive done a few times with tube mics ,
It really simplifies the build and reduces the number of solder joints ,terminals , pin connections and possible failure points , as well as overall component count.
Its also great to be able to throw together a tube mic in an afternoon .


The B&K cathode follower pre-amps have this exact setup , with only grid resistance ,input coupling cap and bias voltage divider at the capsule end of the cable .

 

[rock soderstrom]

Thumbs down from me ,
Thats an attrocity against tube microphones

I knew that my solution would make your pulse racing

What happened to German engineering Rock ?

I don't claim to define new standards for German engineering with a Chinese €15 capsule and a €10 transformer, dude! LOL

Hot glue is a cheapskate way of doing it

This is because the whole thing is a "cheapskate" project, as I'm giving away two microphones and a dual power supply (BTW, for free!) to a young band that I'm helping with their first recording experiences.

A metal cable gland costing a few euros not only provides proper sheilding and continuity to the mic frame

Yes, but to mount it I have the same problems as with an XLR connector. The point was to avoid that, wasn't it? Read the thread again...

It should be possible to tap threads into the hole at the base of the mic to mount up the cable gland ,
I see the type B USB panel cuttaway is 10.5x11.5 mm ,
only basic hand tools are needed ,
a file, to square out the hole , a drill to make it a circle and a tap to cut the threads , job done ,

Well, as I said, there are thousands of solutions to make it better. The XLR version of the SC450 would be one of them...almost all the others have already been mentioned in this thread. What is your point? Are you already drinking at this hour wherever you are? Prost!

At Saturday I will hand over the two microphones to the band ready to play. We'll then record a few things and see how it goes.

I'll read them your email over a beer afterwards!

Cheers Tubey!

 

[Khron]

Yes, but to mount it I have the same problems as with an XLR connector. The point was to avoid that, wasn't it?

Well, unless one managed to find a metal cable gland with a thread diameter that allowed it to be threaded directly into the almost-square USB cutout...

M10's obviously too small, if the smallest dimension is 10.5mm, but what's the next imperial size up?

 

[Tubetec]

The M12 thread tap needs a hole 10.5mm in diameter to begin with , so it should work as it is ,
I'd add two strips of plastic to build out the 11.5mm dimension by 0.5mm on both sides ,
That should be enough to keep the tap centered while you start the cut .