Become a Site Supporter and Never see Ads again!

Author Topic: battery box and extension cable  (Read 1790 times)

0 Members and 1 Guest are viewing this topic.

Offline zupanic

  • Trade Count: (1)
  • Taperssection Regular
  • **
  • Posts: 85
  • Gender: Male
battery box and extension cable
« on: March 30, 2011, 06:58:43 PM »
did a search but did not find the answer...
I am going to be running a pair of Church Audio CA11's on a tall mic stand and need to use an extension cable.
Should I run CA11>battery box>extension cable> recorder    OR
CA11>extension cable>battery box>recorder ?
I'm guessing the first scenario is preferred, but that will force me to fashion-up the battery box somewhere in the middle of the stand.
I am not an electronics wizard by any means and need some advice.
Thanks, Doug

Offline F.O.Bean

  • Is a 4 channel slut and
  • Trade Count: (121)
  • Needs to get out more...
  • *****
  • Posts: 40577
  • Gender: Male
  • Taperus Maximus
Re: battery box and extension cable
« Reply #1 on: March 31, 2011, 10:01:54 PM »
CA11>Extension>BB>Recorder
Schoeps MK4's | MK41's ->
Schoeps | NBob 250/05 KCY's ->
Schoeps VMS 02IB | Naiant +60v/Low Noise PFA's ->
DarkTrain Right Angle Stubby | GakCable XLR's ->
Sound Devices MixPre-6 | Tascam DR-70D ->
128gb | 64gb SanDisk Extreme Pro SDXC-I

http://www.archive.org/bookmarks/diskobean | http://www.archive.org/bookmarks/Bean420 | http://bt.etree.org/mytorrents.php

Offline sunjan

  • Trade Count: (0)
  • Needs to get out more...
  • *****
  • Posts: 2003
  • Gender: Male
  • Taping since 1988, 28 years of fine recordings...
    • Just a handful of stuff I put on etree
Re: battery box and extension cable
« Reply #2 on: April 01, 2011, 04:10:48 AM »
Bean, can you elaborate the reason behind this?
I read somewhere that the impedance of the cables doesn't matter much if the distance is only 2-3 meter or so. Only distances longer than that will cause a noticeable effect. My understanding is also that 2-wire rigs are more sensitive than 3-wire (balanced cables).
Mics: A-51s LE, CK 930, Line Audo CM3, AT853Rx (hc,c,sc),  ECM 121, ECM 909A
Pres: Tinybox, CA-9100, UA5 wmod
Recorders: M10, H116 (CF mod), H340, NJB3
Gearbag: High Sierra Corkscrew
Photo rig: Nikon D70, 18-70mm/3.5-4.5, SB-800
MD transfers: MZ-RH1

Offline Church-Audio

  • Site Supporter
  • Trade Count: (43)
  • Needs to get out more...
  • *
  • Posts: 7554
  • Gender: Male
Re: battery box and extension cable
« Reply #3 on: April 01, 2011, 08:21:31 AM »
If you are using one of my preamps than its recorder-extension-preamp-mics. If you are using a battery box than it does not matter.
The advantage of the preamp is to get the signal as hot as possible as soon as possible so that the level of signal coming out of the preamp is much higher than any inducted noise that might get into the cable.

Chris
for warranty returns email me at
EMAIL Sales@church-audio.com

Offline Karma

  • Trade Count: (0)
  • Taperssection Newbie
  • *
  • Posts: 46
Re: battery box and extension cable
« Reply #4 on: April 01, 2011, 04:34:47 PM »
HI,
Signal loss, per se, is not a problem with mic cables. The currents are so low that the resistence of any reasonable cable will not cause appreciable voltage drops.

What IS an issue is noise pickup. Three wire (balanced) cables and balanced hook ups are far less sensitive to noise, especially 60 Hz hum pick up. This is because the receiving circuits allow the hum to be cancelled in a balanced system. From an electronics point of view, hum pick up is a common mode signal. Input amps have common mode rejection if they are balanced circuits. All mic signals should be three wire (balanced) for maximum noise rejection. And don't think I am picking nits. Balanced configuations are far superior.

The longer the cable run the more important a balanced configuration becomes. But even for short runs, noise can be  factor. Stick with a three wire system.

Sparky

Offline ilduclo

  • Trade Count: (4)
  • Needs to get out more...
  • *****
  • Posts: 3952
Re: battery box and extension cable
« Reply #5 on: April 01, 2011, 05:15:55 PM »
I've run mics (with 3' cords) , 10' extention cord, bb, dat or d50 with no problems.

Offline Karma

  • Trade Count: (0)
  • Taperssection Newbie
  • *
  • Posts: 46
Re: battery box and extension cable
« Reply #6 on: April 01, 2011, 06:23:00 PM »
HI,
Yes, you are right about capacitance with small cables. So, don't use small cables. And this WILL be a function of cable length. And you are also right about circuits that are not true balanced designs. So, use pre amps that are properly balanced. I know this is a problem, one of many, with inexpensive preamps and recorders. Good balanced circuits are expensive. The pro's use nothing else for a reason.

So, if you must live with unbalanced interfaces, you must also live with the potentially noisy consequences. Try to keep your cable lengths short, route them as far away from AC power wiring as you can, and use quality mic cable. This is not black magic.

Sparky

kirk97132

  • Guest
  • Trade Count: (0)
Re: battery box and extension cable
« Reply #7 on: April 01, 2011, 07:23:06 PM »

did a search but did not find the answer...
I am going to be running a pair of Church Audio CA11's on a tall mic stand and need to use an extension cable.
Should I run CA11>battery box>extension cable> recorder    OR
CA11>extension cable>battery box>recorder ?
I'm guessing the first scenario is preferred, but that will force me to fashion-up the battery box somewhere in the middle of the stand.
I am not an electronics wizard by any means and need some advice.
Thanks, Doug

If you are using one of my preamps than its recorder-extension-preamp-mics. If you are using a battery box than it does not matter.
The advantage of the preamp is to get the signal as hot as possible as soon as possible so that the level of signal coming out of the preamp is much higher than any inducted noise that might get into the cable.

Chris
To get this thread back on track, since telling someone to use different gear isn't relative to the original questions posed....
Thanks to Chris for answering the OP questions.  and thanks to msh for addressing the technical theory's involved.  I appreciate the answers and it sheds some light on setting up extension cables for a set of franken naks I am considering building. 

 

RSS | Mobile
Page created in 0.17 seconds with 31 queries.
© 2002-2017 Taperssection.com
Powered by SMF
Website Design by Foxtrot Media, Inc., a Baltimore Website Company