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

On 21 Apr 2005 20:38:18 -0700, "Joe" 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

"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

"Joe" wrote in message
oups.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

Julian Adamaitis wrote:

"Joe" wrote in message
oups.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

"RD Jones" 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

"Julian Adamaitis" wrote in message ...

"RD Jones" 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 !!

On Thu, 21 Apr 2005 23:33:10 -0700, in rec.audio.pro "Julian
Adamaitis" wrote:


"RD Jones" 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/re...tails/2742.pdf



martin

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

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" wrote in message
...

"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

"David Morgan (MAMS)" wrote

Poof !!

Naw, if you short the output, then poof.

"Julian Adamaitis" wrote in message ...

"David Morgan (MAMS)" wrote

Poof !!

Naw, if you short the output, then poof.

Quite right....

Thanks for all the responces to my question
Joe