Film-Tech Forum ARCHIVE: Cable type for sound equipment interconnections.

This is topic Cable type for sound equipment interconnections. in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Stephen Furley (Member # 1277) on 09-11-2013, 07:06 PM:

What type of cable should be used for the various 25 pin interconnecting cables between Dolby DA-20 and DMA8 plus and DTS 6D units? looks like I'm going to have to make my own cables.

Posted by Sam D. Chavez (Member # 1841) on 09-12-2013, 12:21 AM:

I tend to use flat ribbon cables for short distances like 12 to 18 inches and have not had a problem. You can buy them pre made or by a roll of flat ribbon and the IDC connectors, male or female. You can use a small vise to clamp the connector over the the ribbon to make good connections.

Waiting for Steve Guttag to object..

Posted by Stephen Furley (Member # 1277) on 09-12-2013, 04:25 AM:

The diagrams seem to show ribbons for sense/control and some sort of round cables for audio, but it's not clear exactly what it is.

Posted by Louis Bornwasser (Member # 3063) on 09-12-2013, 06:46 AM:

I don't recall the factory cables being shielded, just a multicore, not paired. Seems to work OK at the level and impedance used. Louis

Posted by Scott Norwood (Member # 30) on 09-12-2013, 08:05 AM:

I have been using Gepco GA61806GFC and GA61808GFC snake cable to make DB25->XLR cables. This is probably overkill for connecting a DMA8 to a processor, though. For that, I have been using regular shielded DB25 computer cables, which seem to work OK for short runs, although these will not work in your case since a DA20 (with unbalanced I/O) is involved.

The hardest thing for me to find was DB25 hoods that would accept large-diameter cable. I ended using Amphenol L717DB25P and L77DB25S connectors and 17E-1657-25 hoods. Digi-Key sells these (expensively). It is sort of amazing to think that a DB25->XLR breakout cable will cost about $50+ in parts alone.

Are there better or cheaper options? Probably. No doubt Steve will chime in with the definitive answer.

As a side note: do _not_ buy pre-made DB25 to XLR audio cables. They will have the "Tascam pinout" which is, of course, different from the Dolby version that you actually want.

Posted by Stephen Furley (Member # 1277) on 09-12-2013, 09:39 AM:

No XLRs involved in this Scott. The CP-65 is already connected to the DMA8 plus; I want to add a DA-20 and DTS 6D.

Posted by Stephen Furley (Member # 1277) on 09-13-2013, 07:26 AM:

I assume that any old pair of wires will do for the Dolby motor start relays.

What about the DTS timecode readers; are they fussy about what type of cable they are one? I would guess not.

Posted by Carsten Kurz (Member # 5396) on 09-13-2013, 08:27 AM:

You can use computer D25 cables for automation, etc., no need to make your own there. And yes, Ribbon is okay for short distances.
I have seen DB25 serial/parallel cables being used for short distances for audio as well, but to me that is just too cheap. Also you never know wether these cables are fully wired 1:1 when you buy or recycle them.

For audio, you can buy professional multicore cable by the metre. These are usually twisted pair, so you can also make your own balanced DB25 cables for the more recent Dolby gear with balanced connections. Typical types are 4*2 or 8*2. Thickness just suites typical DB25 connector shells.

http://www.thomann.de/de/the_sssnake_mp08s.htm

http://www.ebay.com/itm/5-8-Channel-DB25-DSUB-SNAKE-w-MOGAMI-2932-NEUTRIK-GOLD-XLR-Female-5/121175289156

http://www.bhphotovideo.com/c/product/888619-REG/Mogami_w2932_00_b_W2932_8_Channel_Multicore_Microphone.html

- Carsten