Focusrite Scarlett 2i2 Gen 3 Performance Measurements

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mediatechnology
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Focusrite Scarlett 2i2 Gen 3 Performance Measurements

Post by mediatechnology » Sun Dec 01, 2019 3:26 pm

I've been wanting to try the Focusrite Scarlett 2i2 particularly since it runs well with Ubuntu 16.04 Linux.

I'm impressed with this little box as a test and measurement interface.
It sounds good too.

The AudioTester results here are with the Scarlett 2i2 running in a Win 7 x64 environment.
The loopback connections are combo-TRS balanced. (The Scarlett's XLR inputs are the mic input.)
The sample rate is 96 kHz 24B depth.
FFT 65 kpts 10 sample avg.

The input gain of the Scarlett 2i2 was calibrated by inputting 2V RMS at the line input and then adjusting the input level until 0dBFS/clipping was observed.
2VRMS (+8.23 dBu) was chosen to approximate unity gain from the TRS input to the A/D modulator.
Virtually every 5V-powered A/D modulator's differential inputs overload at 2V RMS.
By using 2V RMS at the inputs and setting the level for 0 dBFS the overall net gain/attenuation from input to modulator is normalized to unity.
The level controls when set at this point also conveniently line up with the "1" and "2" marks on the front panel around the 11 o'clock position.
The DAC output "Monitor" gain was set to maximum. (Unity internal gain, DAC 0 dBFS is +15 dBu owing to 6 dB gain in the balanced output.)

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Focusrite 2i2 Gen 3 Loopback Balanced TRS-TRS 0dBu 1kHz

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Focusrite 2i2 Gen 3 Loopback Balanced TRS-TRS 0dBu 10kHz

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Focusrite 2i2 Gen 3 Loopback Balanced TRS-TRS -10dBu

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Focusrite 2i2 Gen 3 Loopback Balanced TRS-TRS -10dBu 10kHz

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Focusrite 2i2 Gen 3 Loopback Frequency Response TRS-TRS -3dBFS

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Focusrite 2i2 Gen 3 Loopback Balanced TRS-TRS Idle Channel Noise

Added 12/07/2019.

I checked the Scarlett 2i2 just below clipping and it's still excellent.
In the following two tests the output was raised to +10 dBu (+15 dBu max) and the input gain lowered to just below input clipping at +8 dBu.

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Focusrite 2i2 Gen 3 Loopback Balanced TRS-TRS Output +10dBu Input +8dBu 1kHz

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Focusrite 2i2 Gen 3 Loopback Balanced TRS-TRS Output +10dBu Input +8dBu 10kHz

The unweighted DR of the A/D looks to be about 104 dB.
Though its about 20 dB shy of the PCM4222's 122 dB the THD performance is outstanding.

The output clipping level (balanced) is about +15 dBu.
The Zout is about 220Ω per leg and is not cross-coupled or OutSmarts® gain-compensated.
The line input overload point is around +9 dBu.

The Scarlett 2i2 is going to be a valuable addition to the test bench and its capable of doing everything well except very low-level noise measurements.

FWIW Linux installation was painless: Plug in the USB connector and the Scarlett 2i2 pops up in Pulse Audio. You're done.

Win 7 requires installation of media pre-loaded on the Scarlett 2i2 as well as web downloads.
Win 7's forcing sample rate conversion required me to set the Scarlett 2i2 to 96 kHz even when playing back 44.1 and 48 kHz material and have those sources. presumably, up-sampled to 96 kHz. If I didn't do this, and just set everything to 44.1 to play back 44.1 files, it produced clicking.

ASIO on Win 7 with AudioTester worked well.
Haven't tried ASIO in Linux yet.
https://ka-electronics.com

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billshurv
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Re: Focusrite Scarlett 2i2 Gen 3 Performance Measurements

Post by billshurv » Tue Dec 03, 2019 9:19 am

That does look rather handy for the price as a bench tool.

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JR.
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Re: Focusrite Scarlett 2i2 Gen 3 Performance Measurements

Post by JR. » Tue Dec 03, 2019 11:29 am

Nice, thanx.

Where was this stuff back when I was assembling Heath kit test equipment....? :lol:

Once again modern technology makes life better and easier...

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

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mediatechnology
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Re: Focusrite Scarlett 2i2 Gen 3 Performance Measurements

Post by mediatechnology » Wed Dec 04, 2019 6:04 pm

The Scarlett 2i2 Gen 3 is an incredible value at $159 US.
https://ka-electronics.com

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mediatechnology
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Re: Focusrite Scarlett 2i2 Gen 3 Performance Measurements

Post by mediatechnology » Sat Dec 07, 2019 6:11 pm

Found the high level THD measurements done at +10 dBu out and +8 dBu in.
Posted the FFTs in the OP.
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