First off, this is my first post to a newsgroup that I've spent
a lot of time digging through learning from. Thanks to a whole
bunch of people who've taken my knowledge from zero to staying
up late last night soldering balanced cables for my brand new
(well, okay, Ebay "new") RNP/RNC/LynxOne setup.

Here's my question: Can balanced outputs be wired directly to
headphones, or will I need a mixer (or something) that can go
from balanced to unbalanced in between? How would I wire them
up, if I could? (Pin 2 on the XLR of each output channel to tip
and ring, and a pin 3 to sleeve, maybe?)

Currently I'm playing sound through headphones from my rather
noisy onboard soundcard, and I'd like to go directly out from
the LynxOne to my headphones.

If I do need a balanced-to-unbalanced converter, what are some
lowest cost+lowest noise gear options?

Thanks.

Andrew Klaassen

Andrew wrote
First off, this is my first post to a newsgroup that I've spent
a lot of time digging through learning from. Thanks to a whole
bunch of people who've taken my knowledge from zero to staying
up late last night soldering balanced cables for my brand new
(well, okay, Ebay "new") RNP/RNC/LynxOne setup.

Here's my question: Can balanced outputs be wired directly to
headphones, or will I need a mixer (or something) that can go
from balanced to unbalanced in between? How would I wire them
up, if I could? (Pin 2 on the XLR of each output channel to tip
and ring, and a pin 3 to sleeve, maybe?)

Currently I'm playing sound through headphones from my rather
noisy onboard soundcard, and I'd like to go directly out from
the LynxOne to my headphones.

If I do need a balanced-to-unbalanced converter, what are some
lowest cost+lowest noise gear options?


You need an amplifier, preferably a headphone amp.

"Andrew Klaassen" wrote in message
om

First off, this is my first post to a newsgroup that I've spent
a lot of time digging through learning from. Thanks to a whole
bunch of people who've taken my knowledge from zero to staying
up late last night soldering balanced cables for my brand new
(well, okay, Ebay "new") RNP/RNC/LynxOne setup.

Here's my question: Can balanced outputs be wired directly to
headphones, or will I need a mixer (or something) that can go
from balanced to unbalanced in between? How would I wire them
up, if I could? (Pin 2 on the XLR of each output channel to tip
and ring, and a pin 3 to sleeve, maybe?)

Depends on the headphones and the audio interface.

The load presented by headphones to a source ranges from about 10 ohms to
over 300 ohms.

Some audio interfaces can comfortably drive a 10 ohm load, and others can't.
So, you need to know something about your headphones, and your audio
interface before proceeding.

The output impedance of audio interfaces ranges from a few ohms to a few 100
ohms. The output impedance of an audio interface can interact with the
variable load impedance provided by many headphones, creating with drive
signal that has a highly variable frequency response characteristic.

It turns out that some consumer audio interfaces like the ubiquitous
SoundBlaster cards can drive most headphones fairly well, including low
impedance phones like Sony 7506s.

True audio production cards such as the LynxONE and LynxTWO don't match up
with low impedance headphones very well, but they can work out adequately
with high impedance headphones such as Sennheiser HD580s.

A more flexible alternative than direct drive, is a true headphone buffer or
amplifier, such as are specifically sold for the purpose. I have a Rane HC-4
headphone amplfiier for this purpose, and I feel like it serves me well.

Currently I'm playing sound through headphones from my rather
noisy onboard soundcard, and I'd like to go directly out from
the LynxOne to my headphones.

With the right high-impedance headphones, this might work for you. You need
a converter cable composed of two XLR connectors and an appropriate jack for
your headphones. Cable-mounted headphone jacks are readily available. Hook
pin 2 of each XLR to respective signal terminals on the headphone jack.
Hook wires from either or both XLR pin 1s to the ground terminal on the
headphone jack. If you are working with 3.5 mm jacks, purchasing prefab
cables with the proper jack, and cutting and stripping the cable for
soldering to XLR connectors may simplify your work.

If I do need a balanced-to-unbalanced converter, what are some
lowest cost+lowest noise gear options?

In some cases, low-cost far more limited products such as the "Boostaroo",
also known as Radio Shack part number 330-1109 3-Way Headphone Volume
Booster can work out for you. This device is very clean all by itself, but
its output voltage is limited by its power supply and design, to under 1
volt with the internal batteries, and about 1.6 volts with an external 5
volt power supply. This is adequate for a number of low-impedance and some
high-impedance headphones. I use one with 7506s, and an external 5 volt
supply cribbed from a discarded Comcast cable modem.

"Arny Krueger" wrote in message ...

Hook wires from either or both XLR pin 1s to the ground terminal on the
headphone jack.

So it's better to ground to the cable shielding on pin 1 (whatever it
happens to attach to on the other end) rather than to ground to the
negative signal wire on pin 3?

Thanks for all the other info, too.

Andrew Klaassen

"Andrew Klaassen" wrote in message
om
"Arny Krueger" wrote in message
...

Hook wires from either or both XLR pin 1s to the ground terminal on
the headphone jack.

So it's better to ground to the cable shielding on pin 1 (whatever it
happens to attach to on the other end) rather than to ground to the
negative signal wire on pin 3?

Yes. In a proper balanced system, pin 3 is not ground, it is a signal that
has the opposite polarity of the signal on pin 2.