Topic: Making an AES > SPDIF cable

[Brian Skalinder]

Finally made my AES/EBU > S/PDIF cable.  Pinouts and parts list below.

XLRs from V3 > impedance transformer:

Pin 1 - shield
Pin 2 - (+)
Pin 3 - (-)

BNC/RCA pinout:

Center pin - (+)
Outer ring - (-)
Shield - not used

Parts list (of course, other connectors and cabling may be used, but I've used and liked Canare products in the past):

Qty  |  Markertek Part#  |  Description
------------------------------------------------------------------------------
  1  |  NC3FRC-B         |  3-pin XLR female, right angle, gold contacts
     |                   |  Plugs into V3
 10  |  DA-202           |  2-channel digital audio cable, 110 ohm, 10'
     |                   |  Run b/w female XLR f/V3 and male XLR to imp trans
  1  |  NC3MX-B          |  3-pin XLR male, gold contacts
     |                   |  Plugs into impedance transformer
  1  |  BCJ-XJ-TR        |  Canare # BCJ-XJ-TR, impedance transformer
     |                   |  XLR female, 110 ohm > BNC receptacle, 75 ohm
  1  |  BCP-C4           |  Canare # BCP-C4B
     |                   |  BNC connector, 75 ohm
 10  |  LV-61S BE        |  Canare LV-61S, black, 10'
     |                   |  Digital cable, 75 ohm
  1  |  RCAP-C4A         |  75 ohm RCA connector

Thanks to TapeItNow, an even better suggestion than building the BNC / 75-ohm coax / RCA part of the cable:  simply use a BNC/RCA adapter from Radio Shack, then you can use any old RCA/RCA 75-ohm coax cable to run from the impedance transformer/RS adapter to your deck/7-pin cable or whatever.

[utahtaper]

What I did was make a foot long 110 cable with a rt angle to plug into the MMe/V3 end. Then I bought the 110>75 Canare impedance converter and plugged that into the other end of the 110 cable(which is straight) and I can feed any deck from that connection. I actually reserved that connection for myself and let the patchers have the spdif.

[F.O.Bean]

What I did was make a foot long 110 cable with a rt angle to plug into the MMe/V3 end. Then I bought the 110>75 Canare impedance converter and plugged that into the other end of the 110 cable(which is straight) and I can feed any deck from that connection. I actually reserved that connection for myself and let the

this is my next project w/ the v3

[tim in jersey]

I'm just about ready to build one of these for myself. I plan on using XLR> soldered RCA (one of those cool Neutriks w/ the spring-loaded sleeve).

What is the pin assignment for the RCA end?

[leegeddy]

make sure you're using 75ohm s/pdif (digital) cables.  i highly recommend Canare or Belden brands.

RCA:        XLR:
tip (+)      Pin 2
shield (-)   Pin 3
shield (-)   Pin 1

[adventuregeorge]

Man, those are beautiful  Marc, your work is flawless. I love my cables by the way 

[tim in jersey]

I never did get around to building on of these for myself, lazy bastard that I am. 

[ice8888]

just ordered the parts for this.  is this the correct radio shack part for the bnc > rca cable:

http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=278-303

[Brian Skalinder]

http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=278-303

Looks like that'll do the trick, yes.

[ice8888]

finished making mine.  seems to work.  will give it a full test tonight at the black crowes show here in louisville.  i've attached a picture, although it isn't very good.  damn camera phone.

[twatts (pants are so over-rated...)]

I'd like to get one of these...  about 2-3 feet long...  PM me if you can make one solid...

Terry

[DigiGal]

Here is a much better solution I ran across for this application and made up one of these cables myself using parts on hand.  It works clean from MixPre-D AES to Marantz PMD661 S/PDIF at 24/96.  I can confirm this cable also works going the AES out of a Apogee MiniMe to S/PDIF in on a PMD 661.

A passive impedance conversion AES to S/PDIF cable can be made using a quality 75 ohm coax video cable (i.e. Belden 1505A, Canare LV-61S or equivalent), and to turn the 110 ohm AES source into a 75 ohm impedance install 237 ohms of resistance across pins 2 and 3 within the cables AES's XLR-F connector with the center conductor of coax to pin 2 and shield to pin 1.  Then terminate the other end of the coax with either a 75 ohm BNC or 75 ohm RCA connector to meet your needs.   

The 237 ohm resistance in parallel with the 110 ohm AES source converts it to 75 ohm internally in the XLR-F connector and is then 75 ohm impedance matched all the way to the SPDIF termination.  I've since purchased a large stock of 237 ohm resistors and hand tested/sorted each using my HP3478A Bench Meter to find the ones that meet the tightest tolerance.  My cable utilizes a Neutrik XCC connector which maintains the coaxial shield something that ordinary XLR connectors don't.

EDIT TO ADD: I've had many requests from TS members to sell these cables from another post I made.  If you'd like one please feel free to send me a PM, I'd be glad to make one for you if you're not capable or don't want to make one yourself.  There are now several people out there using my DigiGal AES > S/PDIF passive impedance conversion cable.  I keep stock on hand for a quick build time and am considering posting in the Retail thread since demand has been fairly steady.

 

[Rousselus]

PM to DigiGal : I'd love to buy one of your cable (AES to SPDIF, XLR/F to RCA) to be able to connect my MixPre-D to a PMD 661.
Could you help me ?

[pdxdanmusic]

PM to DigiGal : I'd love to buy one of your cable (AES to SPDIF, XLR/F to RCA) to be able to connect my MixPre-D to a PMD 661.
Could you help me ?

I got one from her about a month ago for my MixPre-D to PMD661 and she does great work. Send her a PM and she will most likely do it. She also did a mod to a AC>DC power supply (I picked up on ebay) to add a hirose power connector and a external battery cable where she added a hirose connector.

[wigglepuppy]

Just got my DigiGal AES > SPDIF cable, It works great, very well made and a super smooth transaction!

Old thread but I just ran across another DIY solution for this and made up one of these cables myself for grins using parts on hand.  Works clean from MixPre-D AES to Marantz PMD661 S/PDIF at 24/96.

So a simple AES to SPDIF cable can be made using a quality 75 ohm coax video cable (i.e. Belden 1505A, Canare LV-61S or equivalent), and to turn the 110 ohm AES source into a 75 ohm impedance install 237 ohms of resistance across pins 2 and 3 within the cables AES's XLR-F connector with the center conductor of coax to pin 2 and shield to pin 1.  Then terminate the other end of the coax with either a 75 ohm BNC or 75 ohm RCA connector to meet your needs.   

The 237 ohm resistance in parallel with the 110 ohm AES source converts it to 75 ohm internally in the XLR-F connector and is then 75 ohm impedance matched all the way to the SPDIF termination.  I've since purchased a large stock of 237 ohm resistors and hand tested/sorted each using my HP3478A Bench Meter to find the ones that meet the tightest tolerance.

I used a Neutrik XCC connector for this build but you could use a standard XLR-F connector too.

EDIT TO ADD: I've had a few requests from TS members to sell these cables.  If you'd like one please feel free to send me a PM, I'd be glad to make one for you if you're not capable or don't want to make one yourself.  I can confirm this cable also works going AES out of a Apogee MiniMe to S/PDIF in on PMD 661.