audio da info needed

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

"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

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?)

"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

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

On 21 Apr 2005 20:38:18 -0700, "Joe" <joemjmsound2@aol.com> wrote:

>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.

This looks like award-winning material. Has Googoo instituted
some contest that I've missed?

Brilliant,

Chris Hornbeck

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?)

On Thu, 21 Apr 2005 23:33:10 -0700, in rec.audio.pro "Julian
Adamaitis" <nospamJulianPA@Access4Less.net> wrote:

>
>"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
>
>
If your output Z is too high, it means that a load will drop the
level, and if you need to parallel two or more devices from one DA
out, you will get levels drops, so a low source Z is "a Good thing"

try
http://www.canford.co.uk/commerce/resources/catdetails/...



martin

After the first death, there is no other.
(Dylan Thomas)

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?)

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?)

"David Morgan (MAMS)" <mams@NOSPAm-a-m-s.com> wrote

> Poof !!

Naw, if you short the output, then poof.

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....

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

Thanks for all the responces to my question
Joe