• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Focusrite Scarlett 2i2 Audio Interface Gen 3 Review

scott wurcer

Major Contributor
Audio Luminary
Technical Expert
Joined
Apr 24, 2019
Messages
1,501
Likes
2,821
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.
 
Last edited:

Blumlein 88

Grand Contributor
Forum Donor
Joined
Feb 23, 2016
Messages
20,521
Likes
37,050
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

Master Contributor
Forum Donor
Joined
Feb 27, 2019
Messages
5,760
Likes
9,442
Location
Europe
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

Major Contributor
Joined
Feb 19, 2018
Messages
4,636
Likes
2,809
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.
 
Last edited:

RayDunzl

Grand Contributor
Central Scrutinizer
Joined
Mar 9, 2016
Messages
13,198
Likes
16,981
Location
Riverview FL
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
 
Last edited:

Music1969

Major Contributor
Joined
Feb 19, 2018
Messages
4,636
Likes
2,809
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

Major Contributor
Joined
Feb 19, 2018
Messages
4,636
Likes
2,809
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

Major Contributor
Joined
Feb 19, 2018
Messages
4,636
Likes
2,809
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

Grand Contributor
Forum Donor
Joined
Feb 23, 2016
Messages
20,521
Likes
37,050

somebodyelse

Major Contributor
Joined
Dec 5, 2018
Messages
3,681
Likes
2,959
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

Major Contributor
Joined
Feb 19, 2018
Messages
4,636
Likes
2,809
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
 

Attachments

  • 1591839133391.png
    1591839133391.png
    70.3 KB · Views: 109

somebodyelse

Major Contributor
Joined
Dec 5, 2018
Messages
3,681
Likes
2,959
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

Major Contributor
Joined
Feb 19, 2018
Messages
4,636
Likes
2,809
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.
 
Last edited:

Helicopter

Major Contributor
Forum Donor
Joined
Aug 13, 2020
Messages
2,693
Likes
3,941
Location
Michigan
I have one of these, and I want to use it to measure some tube amps, and maybe some vintage amps. Maybe I can publish something valuable to others. I am not certain about the best dummy load circuits to measure a speaker or headphone amp... I made a thread here: https://www.audiosciencereview.com/...-outputs-with-focusrite-scarlet-2i2-v3.15759/
hoping not to derail this thread with more discussion of even more specialized DIY cables. But since it is related to this, and I still need help, I am tying my related thread in here. Thanks in advance for any help!
 

CAS

New Member
Joined
Oct 12, 2020
Messages
1
Likes
0
@admin The dynamic range for Mic input in this post is ~106dB. However the spec from Focusrite is 111dB (A weighted). It the measurement method different causing this or the spec is not real?
 

somebodyelse

Major Contributor
Joined
Dec 5, 2018
Messages
3,681
Likes
2,959
@admin The dynamic range for Mic input in this post is ~106dB. However the spec from Focusrite is 111dB (A weighted). It the measurement method different causing this or the spec is not real?
The filter for A weighting will reduce the noise level at low and high frequencies, so the A weighted figure is usually somewhat 'better' than the unweighted figure for the same device. How big the difference is will depend on the noise spectrum. Measurement bandwidth for the unweighted value could also have an influence, similar to the effect of the ultrasonic noise in the DAC part of the 2i2 on the THD+N vs. Frequency plot.
 

tvrgeek

Major Contributor
Joined
Aug 8, 2020
Messages
1,017
Likes
566
Location
North Carolinia
Curious. I have a Gen 1. Quite happy with it for speaker testing, but I notice a big difference in your graphs than mine. My noise floor runs from about -120 dB @ 20 Hz, rising in a strait line to about -94dB @ 20K. You show a flatter noise floor. Is this a feature of the DAC technology, or maybe a feature of my spectrum analyzer? ( TrueRTA) It would be more useful for electronic testing if the noise floor remained lower. If so, I would buy a new one. MOTU specs are slightly better and fancier display. Ever so slightly.

Headphone output can barely make listening levels into my old Yamahamers or my Grado's. Powered from USB, what do you expect?

If you think it is not good enough for home recording, just think back a few years when the best we had was a Sure pre-amp into a Sony quarter track 7 inch reel to reel. This thing is better than the every best studios for when most of my CD collection was recorded.
 
Top Bottom