Topic: Making an AES > SPDIF cable

[DigiGal]

Nice looking bag Marc, I posted photos of my rig combo which uses Portabrace and Marantz cases strapped together in another tread.

I used to use one Tekkeon MP3450 it had a dedicated 5V output to power the PMD661 and I would set the adjustable output to 12V to power the MixPre-D via the Hirose connector.  This battery powered both devices for several shows before needing a re-charge and fit easily in gear bag.  Here's a photo showing the battery as mounted in the Portabrace bag and another showing the bags strapped together, provides gear protection, allows full access and viewing in a nice compact setup for the combo rig.  After having a couple of Tekkeon failure(s) both in and out of warranty decided to make the jump up to a NP1 type battery solution.

[Marc44]

Yes, I see your bag.
Nice so and probably more usefull to have a look on time-code for example.

For Tekkeon MP3450, it's a good idea.
I understand there is a fix output to 5V and another one variable (12V possible).
http://www.tekkeon.com/products-mypall-zoom.html
Is it easy to wire a Hirose connector on the box side?
For 5V , is the same connector for Marantz as for desktop ?

Marc

[DigiGal]

Yes, I see your bag.
Nice so and probably more usefull to have a look on time-code for example.

For Tekkeon MP3450, it's a good idea.
I understand there is a fix output to 5V and another one variable (12V possible).
http://www.tekkeon.com/products-mypall-zoom.html
Is it easy to wire a Hirose connector on the box side?
For 5V , is the same connector for Marantz as for desktop ?

Marc

You'll need to make or buy a Tekkeon cable to Hirose 4-pin power cable for the MixPre-D.  You'll also need to make or buy a USB-A to 1.7mm I.D. x 4.0 O.D. power plug for the PMD661, best to use a beefy USB cable for this.

I wouldn't necessarily recommend that a beginner attempt to make their own Hirose cable but go ahead if you have proficient soldering skills.  Good dexterity, eyes and/or magnifier are certainly useful with Hirose 4 pin connectors.  I made my own but if you're not up to it yourself get in touch with Ted/GAKables for these power cables.

[Marc44]

No, no, I don't want solder an Hirose socket, my dexterity has some limits ...
XLR-3 / RCA: OK but more tiny, I don't try.
It's the reason why  I bought the DV SQN-R , all is included.
Thank for the link Ted/Gakables 
For 5V, I think it's possible to find an USB-A to 1.7mm I.D. x 4.0
For 12V, I don't found a Tekkeon Hirose cable.
Is there a specific socket on  Tekkeon side (12v) ?
If yes , is it easy to  solder ?

A link for expert hands  :
http://www.danmccomb.com/posts/1262/wire-a-tekkeon-battery-to-power-mixpre-and-zoom-h4n/

Marc

[Marc44]

About Vu meters on PMD661  - signal from Mix-Pre-D (thru AES/sp-dif link):
- 1Khz 0 dbu on Mix-Pre-D = -20dbFS on bargraph PMD661 (I think it's normal)
- 1Khz 0 dbu on Mix-Pre-D = -40dbFS on LED scale PMD661
Why such a difference ?

Marc

[tripey]

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.

 

Hey I know this is an old post.  I've been searching around the internet and ran into this thread.  I'm trying to connect spdif from my ad/da converter to another converter that has aes.  I think I'm. understanding how to wire this but the picture with the 3 resistors is confusing me.  Is it 1 resistor wired across pins 2 and 3?  What are the other two resistors?

Thanks

[DigiGal]

Yes old post, if it wasn’t clear the three resistors pictured were from stock I had on hand to make 237 ohm.  You are seeing them wired series-parallel, two wired in series then parallel wired to the third resistor. They were values I had that when combined provided the desired resistance value. Since then I’ve just used a single 237 ohm resistor.  If you are unsure how to combine resistors to achieve the desired resistance or don’t have a supply of resistors to work from then pick up a 237 ohm resistor to wire in parallel with the 110 ohm AES connector for the conversion.