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Gear / Technical Help => Microphones & Setup => Topic started by: hobbes4444 on May 15, 2008, 04:25:30 PM

Title: Nak CM 300 XLR connection question
Post by: hobbes4444 on May 15, 2008, 04:25:30 PM
So in searching around for info on windscreens for CP-4's, I came across a page with what seems to be the instruction manual from Nak CM-300s.  http://www.coutant.org/nakamich/index.html  It says that the cable supplied with the 300s is wired for unbalanced operation (XLR>1/4).  It then says balanced lines should be avoided unless absolutely necessary to avoid noise pick-up problems, since input transformers necessitated by balanced lines inevitably introduce coloration.  Where balanced lines cannot be avoided, the CM-300 may be used with standard 2 conductor plus shield cable, terminating at the micorphone end in a female Cannon XLR (3) type connector, to provide a fully balanced 200 ohm system.

Huh?  So is there a problem running the CM-300s with Canare Star Quad (L-4E6S) cables into a Zefiro InBox (Denecke AD-20) into a D8?  Or would I be better off running the CM-300s with XLR>1/4 and then a Y cable for 2x1/4 female to 1/8 stereo into a D8 or R-09? 

Newbie confusion. . .

Also looking for some, uhm, creative suggestions (VIA PM!!)  for using 300s and CP-4s without a stand, in a non-open, but very laid back open-air  environment (i.e., a park with lawn/sand chairs, blankets, etc)
Title: Re: Nak CM 300 XLR connection question
Post by: Gil on May 15, 2008, 05:01:13 PM
While all of your science-y stuff nearly caused my head to explode, I've never had any problems running them with balanced XLRs into my AD-20.
Title: Re: Nak CM 300 XLR connection question
Post by: hobbes4444 on May 15, 2008, 09:05:15 PM
Nearly?  Thanks for the confirmation . . .
Title: Re: Nak CM 300 XLR connection question
Post by: Roving Sign on May 16, 2008, 08:59:27 AM
The quoted passage does sound a bit confusing...

"Where balanced lines cannot be avoided, the CM-300 may be used with standard 2 conductor plus shield cable,"

I mean - isn't a balanced cable...2 conductors plus shield?

There is a transformer in the mic itself - and - the stock cables have pins 1 and 3 connected...

The question might be  - what happens to the signal when you use a cable that doesnt have pins 1 and 3 connected (i.e. a balanced cable)?? Is it still an unbalanced signal even though you are using a balanced cable...?
Title: Re: Nak CM 300 XLR connection question
Post by: SmokinJoe on May 17, 2008, 07:45:30 AM
I've tried to wrap my brain around that statement a few times too.  I concluded that was written in a different time with different input gear.  I've run typical XLRs into UA-5's and AD-20s, and so have many other people.  Not a problem. 
Title: Re: Nak CM 300 XLR connection question
Post by: rsimms3 on May 17, 2008, 10:10:25 AM
What you have to remember is the correct pin assignments when wiring to mini-XLR.

I bought a set of CM-300s hard wired and they were wired literally number to number.  XLR goes left to right, top to bottom 1-2-3
and mini-XLR goes left to right, top to bottom 1-3-2.  Took me doing some modding to figure out what had happened.  I just rewired mine with the mini connector in the attenuator body and it works fine with phantom adaptors and my CA-9100 preamp now that the pins are in the right places.
Title: Re: Nak CM 300 XLR connection question
Post by: hypnotoad on May 17, 2008, 02:07:03 PM
What you have to remember is the correct pin assignments when wiring to mini-XLR.

I bought a set of CM-300s hard wired and they were wired literally number to number.  XLR goes left to right, top to bottom 1-2-3
and mini-XLR goes left to right, top to bottom 1-3-2.  Took me doing some modding to figure out what had happened.  I just rewired mine with the mini connector in the attenuator body and it works fine with phantom adaptors and my CA-9100 preamp now that the pins are in the right places.

Now that's some good information right there (I'll have to file it away just in case I ever need it).  +t  :)