audio da info needed

Archived from groups: rec.audio.pro (More info?)

I would like to build a passive balaned da with 4 outs. Does anyone
have a link that would give me the resistor values needed? Approx loss?
I will be using a +4 or +8 input.
Thanks Joe

Archived from groups: rec.audio.pro (More info?)

"Joe"
>
>I would like to build a passive balaned da with 4 outs. Does anyone
> have a link that would give me the resistor values needed? Approx loss?
> I will be using a +4 or +8 input.
>


** A typical balanced output can drive many inputs - 10 at least.

Most power amps have male and female input connectors to allow chaining -
if this is not possible them just make a box with one female and 4 male XLRs
with all pin 1s linked, all pin 2s linked and all pin 3s linked.





................ Phil

Archived from groups: rec.audio.pro (More info?)

Julian Adamaitis wrote:

> "Joe" <joemjmsound2@aol.com> wrote in message
> news:1114141098.545549.171680@l41g2000cwc.googlegroups.com...
> >I would like to build a passive balaned da with 4 outs. Does anyone
> > have a link that would give me the resistor values needed? Approx
loss?
> > I will be using a +4 or +8 input.
> > Thanks Joe
>
> One very simple way is to use "build out" resistors. If it is
nominally 600
> ohms balanced in and out to everything, you can use 600/4=150 ohms in
series
> with each plus or minus "leg". If you were only driving 2 devices
you'd use
> 300 ohm.
>
> Julian

Be careful about loading in a situation like this.
When working with a unknown load, or a transformer
I would use no more than 100 ohms, typically 50 ohms.

rd

Archived from groups: rec.audio.pro (More info?)

"Julian Adamaitis" <nospamJulianPA@Access4Less.net> wrote in message news:116h6l7m2ntdk1f@corp.supernews.com...
>
> "RD Jones" <annonn@juno.com> wrote
>
> > Be careful about loading in a situation like this.
> > When working with a unknown load, or a transformer
> > I would use no more than 100 ohms, typically 50 ohms.
>
> I'd usally rather have too much resistance at an output rather than too
> little. Why do you warn against too much?
>
> Julian


Poof !!

Archived from groups: rec.audio.pro (More info?)

Cheapo DA
Agreed, a low Z o/p (1 to 100 ohms) can feed lots of 10k Z inputs without
level/reponse drop.
I usually add a 51 to 75 ohm resistor in each o/p leg from either bus of the
bal i/p pair.
You can run long feeding leads easily. Best keep the o/ps in phase with i/p.
Assuming source is reference of around 1mW, you could even add switchable
50dB bal'd pads in one or two o/ps for deriving mic level.
Ground the (metal) audio distribution box via input XLR pin1, assuming
provider screen is grounded!
But float those multi-output XLRs' pin 1.
The receiving gear will usually provide the grounded screen for its signal
lead
(unless it's battery-powered - in which case you *would* link it to Source
pin1)
Or to be more flexible, add an Earth/Ground Lift/Make spdt mini-toggle per
o/p XLR interrupting its pin1 to common ground bus (from i/p XLR pin1).

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3crd14F6nj6bsU1@individual.net...
>
> "Joe"
>>
>>I would like to build a passive balaned da with 4 outs. Does anyone
>> have a link that would give me the resistor values needed? Approx loss?
>> I will be using a +4 or +8 input.
>>
>
>
> ** A typical balanced output can drive many inputs - 10 at least.
>
> Most power amps have male and female input connectors to allow chaining -
> if this is not possible them just make a box with one female and 4 male
> XLRs with all pin 1s linked, all pin 2s linked and all pin 3s linked.
>
>
>
>
>
> ............... Phil
>
>
>

Archived from groups: rec.audio.pro (More info?)

"Julian Adamaitis" <nospamJulianPA@Access4Less.net> wrote in message news:116itkae9rk4ke2@corp.supernews.com...
>
> "David Morgan (MAMS)" <mams@NOSPAm-a-m-s.com> wrote
>
> > Poof !!
>
> Naw, if you short the output, then poof.

Quite right....