Powersupply for the Dual Bal. Output driver board

Hello,

Today i downloaded the schematics from the SSLtech's website for the dual Balanced Output Driver Board designed by Keith. This Balancing design will be perfect for balancing the different insertpossibilities I have on my two studer 903 desks (one is a submixer). They are unbalanced ins and out. Here you can find the schematic and PCB info:

http://www.beatbazar.com/guests/ssltech/ob-1/index.htm

QUENSTION 1

For the insert sends I'll use this board so in total I'll need 24 boards of them for balancing 16 insert sends pre fileter, 16 insert sends pre fader and 16 direct outs. And this four times for the four buckets of channels I use at the time. As to this moment I have no real cleu of what kind of powersupply I'll need for this as I have no idea of the powerconsumption of these boards. I might just use the + and - 18 V powersupply from the studer as it is overdimensioned anyway and not fully used. But to feel safe if someone can give me an indication on powerconsumption that would be nice.

QUESTION 2

With regard to the insert returns I'll need a design for going balanced to unbalanced and again for 32 times (2 x 16) and again four times. If anyone has a schematic best suited for this, please tell me.

If the project for both PCB boards is finished, I'm more then willing to order a huge batch of PCB's if there is an intrest for this, so that everyone can jump in. If the pcb's are allready available .... I would like to know off cource :grin:

Geert

hi roger it is I suppose,

Thx for the info that was exactly what I neede to know. With regard to question two do you know a cirquit to be used?

Regards,

Geert

[quote author="Geert Heyrman"]hi roger it is I suppose,

Thx for the info that was exactly what I neede to know. With regard to question two do you know a cirquit to be used?

Regards,

Geert[/quote]

Hi Geert,
You were very warm on Keith's site. :wink: Check:
http://www.beatbazar.com/guests/ssltech/
Enjoy

Hi Roger and Gerald thx for the information I'll have a look at it.

Kind regards

Geert

If you want a Ballanceing Curcuit that is jst as simple but cheaper to build then maybe look at this one that uses the TL072 of the NE5532....

http://sound.westhost.com/project51.htm


And for de-balanceing you really don"t need a curcuit from what I understand....You just take Pin 2 and Pin 1 from the Ballanced XLR and you will have a Unballanced Signal(or Pin 1 and 3 if you want opposite Phaze)....

I could be Totally wrong but I don"t think so...


Cheers

Thx,

I'll have a look at it, but I allready have found a nice little studerschematic for this purpose. I have send it to kev. When the PCB-layout is finished I'll post it on the forum.

Geert

[quote author="Minion"]And for de-balanceing you really don"t need a curcuit from what I understand....You just take Pin 2 and Pin 1 from the Ballanced XLR and you will have a Unballanced Signal(or Pin 1 and 3 if you want opposite Phaze)....[/quote]

I have a feeling that would defeat the point of balancing the signal in the first place, as it would prevent common mode rejection from taking place.

No point in splitting them up if you aren't going to reject whats common at the other end, or when they get back.

INA and SSM series have receiver chips....

billy

Do the OB-1's usually get fed phantom power? I'm looking to build something to ballance the unballanced outputs on a synth I have so I'm not sure if I'll be able to go with this one or not?

You can just skip the phantom-blocker stuff if you are sure that there'll be no phantom.

That westhost circuit will NOT drive a short-circuit to ground without crosstalk.. lots of it. The SSM2141, Burr-Brown DRV134 or THAT equivalent (from Wayne 'mediatechnology') is a much better bet.

Keith