Balanced to unbalanced.

[Tobiah]

I feel like this may be a stupid question, but here it is.
I need to connect 1/4" TRS balanced mixer outputs to
RCA ins on an amplifier. Is there any benefit to using
a TRS plug on the mixer side, running all three wires
to the RCA? I assume I'd just tie one of the signals
to ground, which is really the same as just using a
TS connector at the mixer, but was wondering whether
I'd still get the interference rejection by running
both signals through the wire. As I'm typing this
the idea sounds wrong, but I'll let the question stand
at the risk of embarrassment.

[Don Pearce]

On Fri, 9 Jul 2021 08:59:04 -0700, Tobiah <toby...@tobiah.org>
wrote:

Nope, just a normal mono quarter inch plug to the RCA.

d

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[Mike Rivers]

On 7/9/2021 11:59 AM, Tobiah wrote:
> I feel like this may be a stupid question, but here it is.
> I need to connect 1/4" TRS balanced mixer outputs to
> RCA ins on an amplifier.  Is there any benefit to using
> a TRS plug on the mixer side, running all three wires
> to the RCA?

It's not that simple. It depends on the configuration of the balanced
output, and there are several. You need to be sure that the high and low
signal leads (normally the tip and ring) go to the tip and sleeve of the
RCA. But what you do with the sleeve (shield) depends on the
configuration. Some differential outputs don't like having the low
signal lead tied to ground and you'll get distortion. A
"balanced/unbalanced" output has no signal on the ring, though it's
often tied to ground through a resistor. For those outputs, the best way
to connect to an RCA is between the tip and sleeve/shield.

Check out this article and figure out what kind of output you have:

https://crookwood.com/blog/dealing-with-unbalanced-gear-in-the-studio/


--
For a good time, call http://mikeriversaudio.wordpress.com

[Tobiah]

> Check out this article and figure out what kind of output you have:
>
> https://crookwood.com/blog/dealing-with-unbalanced-gear-in-the-studio/
>

The article says:

At the unbalanced end, always connect the hot wire to the output or input pin, and the cold wire to the ground pin

So I would run all three wires, connect the output tip to the RCA pin,
and the output ring to the RCS sleeve, and run the output sleeve through
the wire, but not connect it to anything on the RCA side.

Now, wouldn't this give me a larger signal to the amp as compared to
using a tip/sleeve plug on the output?


Mixer is a Mackie 1402 VLZ Pro.

[Mike Rivers]

On 7/9/2021 1:50 PM, Tobiah wrote:

> So I would run all three wires, connect the output tip to the RCA pin,
> and the output ring to the RCS sleeve, and run the output sleeve through
> the wire, but not connect it to anything on the RCA side.

> Mixer is a Mackie 1402 VLZ Pro.

The 1/4" TRS outputs on that mixer are of the "balanced/unbalanced"
sort. You can connect either the low (ring) wire or the shield to the
sleeve of the RCA plug. It makes no difference since there's no signal
on the low wire. You could use single-conductor shielded wire if you
want, connecting to just the tip and sleeve. I prefer using two
conductor cable to be prepared if in the future I replace whatever has
the RCA jacks with something that has a differential (balanced) input.
It saves having to replace the cable and just means rewiring the plugs.

> Now, wouldn't this give me a larger signal to the amp as compared to
> using a tip/sleeve plug on the output?

If the output was differential (which it isn't), you'd get half the
specified output voltage between the tip and sleeve, and the same
voltage with the opposite polarity between the ring and sleeve. So
between the tip and ring, you get twice the voltage as between either
one and the sleeve. But since you don't have a differential output, you
don't gain anything by connecting the RCA plug between the tip and ring
of the TRS plug.

[Scott Dorsey]

There is a whole section on this on the Rane website and a very cool
app note about it.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[palli...@gmail.com]

Tobiah wrote:
============

>
> I feel like this may be a stupid question, but here it is.
> I need to connect 1/4" TRS balanced mixer outputs to
> RCA ins on an amplifier.

*So you need a 1/4 inch mono plug to RCA plug lead.

>Is there any benefit to using
> a TRS plug on the mixer side, running all three wires
> to the RCA?

**None.

I assume I'd just tie one of the signals
> to ground,

** Never short an output to ground - it's stupid.

Only needed when transformers are involved.

> which is really the same as just using a
> TS connector at the mixer, but was wondering whether
> I'd still get the interference rejection by running
> both signals through the wire.

** Nope.

FYI:

There is no " interference" issue.
Maybe a tiny hum loop created if the amp and mixer are both safety gounded.

Try it and see FFS.

[palli...@gmail.com]

Tobiah wrote:
=============

>
> >
> > https://crookwood.com/blog/dealing-with-unbalanced-gear-in-the-studio/
> >
> The article says:
>
> At the unbalanced end, always connect the hot wire to the output or input pin, and the cold wire to the ground pin

** Bad advice.

Contadicts what is in the main part of that dumb article.

Says:

"Hard balanced outputs *cannot* be shorted to ground ".


...... Phil

[Mike Rivers]

On 7/9/2021 9:28 PM, palli...@gmail.com wrote:

> "Hard balanced outputs*cannot* be shorted to ground ".

Nothing you read on the Internet is perfeck. What's a "hard balanced
output" anyway? A made-up term for the sake of an article?

My explanation was more specific - For an output that's differential,
with the "low" output actually "hot" too, being the "high" output
inverted, connecting the "low" output to ground may cause distortion,
loss of headroom, or, in worst case, component damage.

However, a differential output with a cross-coupled configuration is
perfectly happy having its "low" side tied to ground. That puts the two
outputs in series and you don't lose half the voltage that you do by
leaving the "low" side of an inverted "high" output floating.

The Rane article that Scott pointed out is much better, but when I
wanted to point to it, I couldn't remember that it was from Rane. CRS
syndrome here, you know.

[palli...@gmail.com]

Mike Rivers wrote:
=================

> > "Hard balanced outputs*cannot* be shorted to ground ".
>
> Nothing you read on the Internet is perfeck. What's a "hard balanced
> output" anyway? A made-up term for the sake of an article?

** It was defined in the article.

Means twin, out of phase, ground referenced electronic outputs.
Usually, a pair of op-amps, one unity gain inverting and the other a simple follower.
You must not short the follower.

Not possible for ordinary users to know which is which.

IME a lot of twaddle is published about "balancing".



..... Phil

[Don Pearce]

Connect ground and one signal. If there is sound, you have a
ground-referenced balance. If there is no sound it is a floating
balance, and the other signal lead should be grounded.

[Anthony Kuzub]

TRS outputs are mostly impedance balanced outputs... Mostly.

XLR AES14 and AES59 are mostly differentially balanced...

Using a TS connection In this case, the tip would be signal (hot, non inverted signal) the ring (normally inverted) would be shorted to the sleeve. Because it's impedance balance, there is no signal at the inverting ring... So there is no real danger of blowing up the driver circuit when shorting the ring to sleeve.

Guitar player proof!

Anthony

[Mike Rivers]

On 7/11/2021 7:40 AM, Anthony Kuzub wrote:
> TRS outputs are mostly impedance balanced outputs... Mostly.

ALL balanced outputs are "impedance balanced." The definition of a
balanced output is one with both the high and low side having the same
impedance to a reference point (usually "ground"). "Balanced" doesn't
involve voltage.

Also, "balanced input" is a misnomer. It's a "differential" input, which
depends on being connected to a balanced output in order to take
advantage of its common mode rejection,

> XLR AES14 and AES59 are mostly differentially balanced...

Yup.

>> <palli...@gmail.com> wrote:

>>> Mike Rivers wrote:
>>>> What's a "hard balanced output" anyway? A made-up term for the sake of an article?

>>> ** It was defined in the article.

Hardly a formal definition. It's not a common term. "Impedance
balanced," on the other hand, seems to have entered the common
vocabulary anyway. I can't say for sure that I invented that term, but I
made it up (perhaps independently of someone more famous) to describe
this output configuration that, while it's been around for a long time
(some famous microphones use that output configuration) it was
popularized with the proliferation of Mackie mixers and their followers.

<palli...@gmail.com> wrote:

>>> Means twin, out of phase, ground referenced electronic outputs.
>>> Usually, a pair of op-amps, one unity gain inverting and the other a simple follower.
>>> You must not short the follower.

Yup

>>> Not possible for ordinary users to know which is which.

Easily discovered with a little experimentation, though I'll concede
that most "ordinary" users - those who have little or no technical
knowledge on the subject - need to be told how to sort this out.

>>> IME a lot of twaddle is published about "balancing".

That's for sure.

[palli...@gmail.com]

Mike Rivers wrote:
===============

>
>>>> ** It was defined in the article.
>>
> Hardly a formal definition. It's not a common term. "Impedance
> balanced," on the other hand, seems to have entered the common
> vocabulary anyway. I can't say for sure that I invented that term, but I
> made it up (perhaps independently of someone more famous) to describe
> this output configuration that, while it's been around for a long time
> (some famous microphones use that output configuration) it was
> popularized with the proliferation of Mackie mixers and their followers.

** IME:

1. Impedance balanced = output with one active line and one passive both with the same effective impedance to ground.
Some Rode condenser mics have this, designer Doug Ford liked it ( he told me so).

2. Ground cancelling output = a single op-amp stage with one active and one return line that is actually an input.
Identical impedance to ground with both.
Soundcraft " Spirit " series desks all have this.

> >>> IME a lot of twaddle is published about "balancing".
> That's for sure.

** :-)


..... Phil

[Anthony Kuzub]

Thanks, Mike

For sure, lots of misnomers and marketing... . Impedance Balanced is a weird term that hides the fact that it's not differential.

To sum the above up All balanced lines are impedance balanced including differential... but not all impedance matched are differential.

I do think voltage plays a role in differentially driven outputs... there is potential on both wires :-)

I too am seeking better words: AES-X152: AES standard on interconnections - Audio interconnection specifications
The goal/target/deliverable is a template that manufacturers could include in their manuals that explains the characteristics of the signals leaving devices and the characteristics of signals a device is capable of receiving. Having these parameters summarized in a consistent way will help users integrate equipment.

I hope you're able to contribute to the AES work.

Anthony

[Tobiah]

Well there has been a lot of interesting discussion
about this, but wasn't able to glean a solid conclusion
from it. I'll just use a standard two conductor
1/4" at the mixer wired to the RCA.

[Mike Rivers]

That as well as anything, until you want to hook up something really
balanced.

[Mike Rivers]

On 7/11/2021 5:12 PM, Mike Rivers wrote:
>
> That as well as anything, until you want to hook up something really
> balanced.

What happened to the rest of my sentence? It was supposed to read: "That
should work as well as anything . . ."

[palli...@gmail.com]

anthon...@gmail.com wrote:
======================

>
> Using a TS connection In this case, the tip would be signal (hot, non inverted signal)
> the ring (normally inverted) would be shorted to the sleeve.
> Because it's impedance balance, there is no signal at the inverting ring...
> So there is no real danger of blowing up the driver circuit when shorting the ring to sleeve.

--------------
>
> Guitar player proof!
>

** Gotta disagree there - nothing is guitar player proof !

I once saw a near new Mackie 1604 *destroyed* by a guitar player.
Wanting to feed his 100W Marshall into the desk, he used a spare speaker jack on the back.
The approx 40VAC signal found it way onto the 16V DC rails and blew the PSU.
Then blew most of the op-amps too.


..... Phil

[Anthony Kuzub]

Guitar... It's the only amplified thing we collectively agree needs more amplification.

Not all idiots play guitar, us who can't wished they could.

Anthony

[Dieter Michel]

Mike,

>> That as well as anything, until you want to hook up
>> something really balanced.

> What happened to the rest of my sentence? It was supposed
> to read: "That should work as well as anything . . ."

maybe it didn't escape the unnecessarity filter ;^))

It was understandable anyway.

SCNR,

Dieter

[Chris K-Man]

_________

"SCNR"??

[Dieter Michel]

Sorry, Could Not Resist

[Chris K-Man]

____

Thank You


"TY" (for the Gen Zs)

[Scott Dorsey]

I knew someone once who ate an entire sheet of blotter acid. They went from
balanced to unbalanced pretty quickly.