Topic: AT 831B - cutting them free

[dphirschler]

I have a pair of AT 831B mics that I love, but have wanted to cut them free from the bulky battery box for years.  Well, after the batter box started developing problems I decided to finally do it.  So I cut them free.  I was expecting  two wires inside the cable, a positive and a ground.  What I found surprised me and now I do not know how to wire them up to a stereo 1/8" connector.  The wires inside each mic cable are as follows:

2 yellow
2 red
1 shield

Can anybody tell me how they should be wired up?  Thanks in advance.


Darryl

[ArchivalAudio]

this might be better placed in the Microphones section...since this is really a mic question
however
Chris
at Church Audio
might
be of help?
I dunno


I searched the mic section for
AT831B
and got
http://taperssection.com/index.php/topic,42835.0.html

also check out Sound Professionals
perhaps

good luck

peace
-- Ian

[Church-Audio]

I have a pair of AT 831B mics that I love, but have wanted to cut them free from the bulky battery box for years.  Well, after the batter box started developing problems I decided to finally do it.  So I cut them free.  I was expecting  two wires inside the cable, a positive and a ground.  What I found surprised me and now I do not know how to wire them up to a stereo 1/8" connector.  The wires inside each mic cable are as follows:

2 yellow
2 red
1 shield

Can anybody tell me how they should be wired up?  Thanks in advance.


Darryl

Take the Yellow wire and connect it to ground with the shield. And the Red wire goes to the ring or tip You can put a 4.7k resistor in between the yellow wire and the shield for my hi spl mod.

Chris

[ArchivalAudio]

Chris,
thanx
I figured you would know what to do...
I though about the 4.7k mod and originally included it
but
I knew you could give the correct info

thanx

-- Ian

[dphirschler]

Thanks Chris and Ian.  I will try this out next time I get out the soldering iron.  Will I need a high quality resistor or will the Radio Shack one work fine?  ... assuming Radio Shack still sells those things.


Darryl

[Church-Audio]

Thanks Chris and Ian.  I will try this out next time I get out the soldering iron.  Will I need a high quality resistor or will the Radio Shack one work fine?  ... assuming Radio Shack still sells those things.


Darryl

You should use metal film resistors I am pretty sure radio shack sells them in the USA. I would also use a 1% if you can find it if not use a meter and try and match them the best you can. Because if they are way off that will change your output from mic to mic. Also you can send me $3.00 for postage and I can send you a few in the mail. You also dont need anything over 1/2 watt. even 1/8th watt will be fine.


Chris

[rsimms3]

Thread on adaptor cable, can be used as guide to do what you want.
http://taperssection.com/index.php?topic=93011.0

Resistors at Radioshack, where I got mine.
http://www.radioshack.com/product/index.jsp?productId=2062305&cp=&sr=1&origkw=metal+film+resistors&kw=metal+film+resistors&parentPage=search

[dphirschler]

Can you explain the logic behind the 4.7k resistor?  What does it accomplish and how?


Darryl

[dphirschler]

I thought I should report back with my results.  I soldered it up to a stereo connector per your instructions (no resistor though) and it works great!  I decided I don't need the resistor since my battery box has an adjustable attenuator built right into the cable.  I thought I had messed something up at first because there was a buzzing sound in the left channel, but it turned out it was just a new connector not making good connection.  Unplugging and replugging several times did the trick.

Thanks for the help guys.  Cutting these mics free from their bulky battery boxes (that's right they each had a box complete with bulky XLR connector) and using them with the smaller Sound Professionals battery box has given them new life!  And now they are stealthier than ever!  Muhahahaha!!


Darryl

[fmaderjr]

I decided I don't need the resistor since my battery box has an adjustable attenuator built right into the cable. 

If it was that easy there wouldn't be much talk here about the 4.7 mod. Attenuating the signal to the recorder will not keep the mic capsules from overloading in high sound pressure situations. That is the reason people do the 4.7 mod.

Without the mod, you mics will work fine in most situations, but won't be reliable in extremely high SPL situations (especially if you like to stack tape loud concerts).

[Church-Audio]

I decided I don't need the resistor since my battery box has an adjustable attenuator built right into the cable. 

If it was that easy there wouldn't be much talk here about the 4.7 mod. Attenuating the signal to the recorder will not keep the mic capsules from overloading in high sound pressure situations. That is the reason people do the 4.7 mod.

Without the mod, you mics will work fine in most situations, but won't be reliable in extremely high SPL situations (especially if you like to stack tape loud concerts).

Attenuating an already "distorted signal" just makes it a "quiet already distorted signal" Muhahahaha!!
Some companies that shall remain nameless have tried to fix the problem that way and it does not work. The only reason why you might get less distortion is the gig your recording is not loud enough to cause distortion therefore its impossible to know the net result of anything with out first approaching it in a some what scientific way of at least being able to "measure the acoustic level of the show" and distortion in a percentage form.

Chris