[LAU] Sound quality of the Focusrite Scarlett 18i20 2nd Gen

Hi, first of all, with a non-rt kernel 4.8.13-1-ARCH threadirqs the Presonus worked with 256 frames/period, in this regard the Focusrite is better, it's possible to use it with 128 frames/period. I used the same Qtractor song with fluid-dssi and hexter, as I used for the Presonus. I didn't test S/PDIF. I returned the Presonus, so I can't compare the Presonus and Focusrite directly. The headphone outputs of the Focusrite are the most worse I ever heard. I made a test with 44.1 KHz. I ripped "weather with you" from a Crowded House CD. Ardour played the ripped WAV and a CD player played the original CD. A comparison with the RME HDSPe AIO's headphone output makes no sense. I hoped that just the headphone amps of the Focusrite are weak, so I compared the sound quality of the Focusrite's analog outputs with a Behringer ADA8000 connected by ADAT with the Focusrite, using the same cables and mixer channel and then by listening to the mixing console's headphone amp. After that I used the same cables to connect the Focusrite and the ADA8000 to a hifi amp, without a mixer involved. The ADA8000's sound quality always is more or less equal to a hifi CD player, the sound of the Focusrite was always vastly worse. Not only nuances are missing in the audio signal, but I have the impression that the bass is purposely boosted. Since I need a device that provides ADAT and works with my iPad, I'll continue testing, but for Linux usage only, without an ADAT device, I suspect the Presonus is the better choice. I suspect the Focusrite's headphone and analog outputs are completely unusable for home recording. At least I would send back the Focusrite, if I wouldn't need DAT for the iPad. The sound is close to a cheap no-name Walkman with a bass boost feature. Using studio headphones there anyway is some 80s Walkman headphone alike sound impression. It doesn't require blind tests to compare a telephone with a hifi amp. The Focusrite's sound is better than a telephone, but I want to make clear, that there's an audible difference compared with other gear, that doesn't require blind tests. FWIW the front is made of plastic and a countersunk bolt isn't completely countersunk, but the cross recess of the screw is damaged. It's a brand new device, not a b-stock. Regards, Ralf