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Focusrite Scarlett 2i2 Audio Interface Gen 3 Review

scott wurcer

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That's what I don't know. They should, by all measurements, sound the same. There's no reason they should be any different, and yet they are.
You are comparing a complete product with a particular input device to some un-named circuit using another IC. Has someone modded the Scarlett with that TI part and performed a DBT to make this determination?

EDIT - At that price point this part would never be used in a consumer product with a $160 price. A mod with this part would be a large undertaking, far better would be the mic pre-amps from THAT such as the THAT1512.
 
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Blumlein 88

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This post by @sergeauckland covers it pretty well. https://www.audiosciencereview.com/...-to-single-ended-connection.13034/post-389484
My apologies if this has been covered as I didn't read all 7 pages.

I don't know about the gen 3 Scarletts, but earlier generations were impedance balanced and shouldn't be bothered with pin 3 grounded.

You can check this pretty easily. With power off using a TSR cable check resistance between the sleeve to the tip and the ring. One will read a rather high and possibly fluctuating resistance. One will read a moderately low and fixed unchanging resistance. This is the connection that isn't connected to an active op-amp rather just resistance coupled. Explained and illustrated here:
https://www.soundonsound.com/sound-advice/q-how-impedance-balancing-audio-different-normal-balancing


Unbalancing a balanced differential output by shorting XLR pin3 (jack ring) to ground is fine or not, depending on the type of balanced output.

If fully floating transformer balanced, that perfectly fine.
If centre-tapped transformer balanced that's not fine at all as half the transformer gets shorted out. Pin 3 needs to be left unconnected in this case.

However, most outputs these days are not transformer balanced, but use electronics. These can also be OK or not.

If the output is electronically servoed, then it's effectively 'fully floating' i.e. not ground referenced, so shorting pin 3 (jack ring) to ground is fine.
If the output is just plain electronically balanced, i.e. with an opamp on each leg, then it's not OK as one leg will be shorted to ground. Usually each opamp has a series resistor to protect the output against just such an occurrence, but that raises the output impedance from essentially zero ohms to 75-100 ohms so sometimes isn't done.
If the output isn't differential, just impedance balanced, then shorting pin 3 (jack ring) to ground should be fine assuming the sensible case that it's pin 2 that actually carries the signal.

In summary, it's impossible to know what's the right way unless you know what sort of output you have. In many cases, the manual will tell you how to unbalance the output. If they don't then the safest is to leave pin 3 (jack ring) floating, and if that works, then great. If the sound is weak, with only high frequencies, then pin 3 needs to be tied to pin 1 (ground).
 

LTig

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Hi, thanks for all the info but I'm confused why TRS-to-RCA would be needed when the Focusrite supports TS unbalanced output (screenshot from manual below) and there exists TS-to-RCA cables, like the Mogami I linked.

Apologies in advance if this is a stupid question, but am I missing something very obvious here?

http://www.mogamicable.com/category/products/gold_TS-RCA_6_12.php


View attachment 66749
No, you do not miss anything. You did what I wrote in posting #105: you've read the manual. This states that it is OK to use an unbalanced TS connector. So do it. There are circuits which allow this, and the 2i2 has such one.
 

Music1969

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No, you do not miss anything. You did what I wrote in posting #105: you've read the manual. This states that it is OK to use an unbalanced TS connector. So do it. There are circuits which allow this, and the 2i2 has such one.
Thanks!

All the replies I’ve received are talking about wiring TRS balanced to RCA.

But there exists TS to RCA cables and the manual states TS unbalanced is fine, so I was really confused.
 
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RayDunzl

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For grins:

Using a Clarett 4Pre USB device.

Compare cheap XLR mic cable and TS unbalanced guitar cable plugged into balanced TRS input and outputs.


REW Tone at -0.10dBfs -> USB -> Topping D10 -> S/PDIF non-coaxial RCA cable -> Switch -> Optical -> Focusrite channels 3 and 4

Focusrite Ch 3 output -> No name 25 foot XLR with XLR/TRS adapters on both ends -> Focusrite Ch 5 input -> USB Out to REW

Focusrite Ch 4 output -> No name 15 foot TS Guitar Cable -> Focusrite Ch 6 input -> USB Out to REW


1591167201064.png


A little power and USB (?) noise on the unbalanced, at levels that are in the don't care zone, unless you do.

Without signal:

1591168918930.png
 
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Music1969

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Nope. You have to read the manual. RME states for the ADI-2 PRO fs that you should not plug a mono TRS connector into the stereo TRS plug because this shortcuts the (-) signal which may lead to higher distortion.
Can you show where this is in the manual?

@Panelhead was talking about the 1/4" output there and in the manual I see the below.

I think you are only talking about XLR outputs when connecting to unbalance but @Panelhead mentioned 1/4" outputs which support both TRS and TS, as per:


1591792972128.png
 

Music1969

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Same applies to RME Fireface UC's 1/4" outputs, they support TS also

1591793311314.png



This warning below wouldn't apply to the Mogami TS-to-RCA cables I orginally asked about, right? It's only applicable to TRS jacks which is not the cable I asked about

1591793439377.png
 

Music1969

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That warning appears to be about TRS INputs.
It's under the line outputs section, as per screenshot above.

I think the warning applies to both 1/4" input and output... but again, not applicable to TS connectors like the Mogami I initially asked about
 

Blumlein 88

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somebodyelse

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It's under the line outputs section, as per screenshot above.

I think the warning applies to both 1/4" input and output... but again, not applicable to TS connectors like the Mogami I initially asked about
We're talking about https://www.rme-audio.de/downloads/fface_uc_e.pdf aren't we?
Manually doing image-to-text since it didn't appear as expected when quoted, and adding emphasis:
When using unbalanced cables with TRS jacks: be sure to connect the 'ring' contact of the TRS jack to ground. Otherwise noise may occur, caused by the unconnected negative input of the balanced input.
This is NOT in section "23. Analog Outputs" or its subsections in the version I see. It is in sections 22.1 and 22.3 regarding analog inputs though.
For inputs the sleeve of the TS plug will connect the negative input to ground, so not applicable as you say.
 

Music1969

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We're talking about https://www.rme-audio.de/downloads/fface_uc_e.pdf aren't we?
Manually doing image-to-text since it didn't appear as expected when quoted, and adding emphasis:

This is NOT in section "23. Analog Outputs" or its subsections in the version I see. It is in sections 22.1 and 22.3 regarding analog inputs though.
For inputs the sleeve of the TS plug will connect the negative input to ground, so not applicable as you say.
Noted but regarding outputs (as per my original query), from the manual:

1591839187797.png


and

1591839240665.png
 

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somebodyelse

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I just wanted to be sure you weren't mixing up requirements for inputs and outputs. For the outputs the part I'd highlight is:
The electronic output stage is build in a servo balanced design which handles unbalanced (mono jacks) and balanced (stereo jacks) correctly.
The mono jacks are the TS ones you're talking about, and RME are explicitly saying these outputs are built to handle them.
 

Music1969

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Hi all, is the volume control for this interface digital? For both headphones and line outs?

I didn't see any channel volume balance measurement in @amirm 's opening post.
 
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