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

Hi Tom, thank you for reporting your experiences. Until now I only tested the outputs. Not only the headphone outputs sound bad, the analog line outputs sound disgusting, too. The sound is comparable to turning on Dolby B on a cheap tape recorder, without pumping, but with cutting highs and in addition with boosting bass or like having dirt in the ear or having hearing issues caused by a cold. All analog outputs are unusable crap. The companies claim that it's a professional device is a lie, it's even not a home recording or cheap hifi device. I experienced a new issue, that might be an issue for all USB devices on my machine. I didn't do that much tests with the Presonus as I already did with the Focusrite. A few times Qtractor as well as Ardour had issues to read WAV data from the hard disk. Fortunately Ardour informs about the reason, Qtractor doesn't. One time I needed to restart the computer to get rid of it. I tested two SATA HDDs, so it's seemingly not a broken HDD, but most likely an issue related to USB. It seems not to be related to an IRQ... [rocketmouse@archlinux ~]$ rtirq status PID CLS RTPRIO NI PRI %CPU STAT COMMAND 126 FF 90 - 130 0.2 S irq/19-ehci_hcd 130 FF 90 - 130 0.0 S irq/16-ohci_hcd 152 FF 89 - 129 0.0 S irq/17-ohci_hcd 154 FF 88 - 128 0.0 S irq/18-ohci_hcd 155 FF 88 - 128 0.0 S irq/17-ohci_hcd 157 FF 87 - 127 0.0 S irq/18-ohci_hcd 274 FF 85 - 125 0.0 S irq/18-snd_hdsp 32 FF 50 - 90 0.0 S irq/9-acpi 48 FF 50 - 90 0.0 S irq/8-rtc0 78 FF 50 - 90 0.0 S irq/26-radeon 115 FF 50 - 90 0.0 S irq/1-i8042 129 FF 50 - 90 0.0 S irq/22-firewire 132 FF 50 - 90 0.0 S irq/22-ahci[000 142 FF 50 - 90 0.0 S irq/14-pata_ati 143 FF 50 - 90 0.0 S irq/15-pata_ati 261 FF 50 - 90 0.0 S irq/7-parport0 436 FF 50 - 90 0.0 S irq/27-enp3s0 3 TS - 0 19 0.0 S ksoftirqd/0 17 TS - 0 19 0.0 S ksoftirqd/1 ...ahci doesn't share its IRQ with USB. However, I'll continue with some fine tuning. [rocketmouse@archlinux ~]$ sudo modprobe -r pata_atiixp [rocketmouse@archlinux ~]$ sudo modprobe -r firewire-ohci; sudo modprobe -r firewire_core [rocketmouse@archlinux ~]$ sudo modprobe -r ppdev; sudo modprobe -r lp [rocketmouse@archlinux ~]$ cd /sys/bus/pci/drivers/ohci-pci [rocketmouse@archlinux ohci-pci]$ printf "0000:00:13.2" | sudo tee unbind >/dev/null [rocketmouse@archlinux ohci-pci]$ printf "0000:00:13.4" | sudo tee unbind >/dev/null [rocketmouse@archlinux ohci-pci]$ rtirq status PID CLS RTPRIO NI PRI %CPU STAT COMMAND 126 FF 90 - 130 0.2 S irq/19-ehci_hcd 130 FF 90 - 130 0.0 S irq/16-ohci_hcd 152 FF 89 - 129 0.0 S irq/17-ohci_hcd 155 FF 88 - 128 0.0 S irq/17-ohci_hcd 274 FF 85 - 125 0.0 S irq/18-snd_hdsp 32 FF 50 - 90 0.0 S irq/9-acpi 48 FF 50 - 90 0.0 S irq/8-rtc0 78 FF 50 - 90 0.0 S irq/26-radeon 115 FF 50 - 90 0.0 S irq/1-i8042 132 FF 50 - 90 0.0 S irq/22-ahci[000 261 FF 50 - 90 0.0 S irq/7-parport0 436 FF 50 - 90 0.0 S irq/27-enp3s0 3 TS - 0 19 0.0 S ksoftirqd/0 17 TS - 0 19 0.0 S ksoftirqd/1 The Presonus and Focusrite cost < 400 EUR, alternatively there are just 2 Behringer for < 300 EUR and 1 RME for > 600 EUR. I don't test the Behringer devices, because I read customer reviews mentioning power supply failures for one of those devices and I had to replace caps of my Behringer mixer's switching power supply and the power supply of my ADA8000 gets boiling hot. I guess the only reason that the ADA's power supply didn't break is, that I rarely used it. Apart from this I had to clean all knobs of my Behringer mixing console. I'm living close to a main street and dirt is a serious issue, however, all of my gear suffers from the same dirt, but just the Behringer mixer needed a radical cleaning in a shorter space of time. The RME is too expensive. If all ADAT channels of my RME HDSPe AIO of my Linux PC would work, I would buy and test the RME USB audio interface, but because they don't, there's a Linux driver issue or I'm to stupid to understand how to use it, I need to buy two devices, one for the iPad and a second for the Linux PC, so the RME interface is too expensive for me at the moment. I continue testing the Focusrite now, assuming there should be no additional issues, at least no issues for the iPad, I'll stay with the Focusrite and use it for MIDI and ADAT. I still need to test the analog inputs, perhaps they are usable. I also will call my dealer, too ensure that the output sound isn't bad, because something is broken. The analog outputs of the RME HDSPe AIO and the Behringer ADA8000 do not sound that bad, so it's not some technical issue with my PC, mixer, amp or ears. The culprits are the analog outputs of the Focusrite. My two TerraTec EWX 24/96 cards aren't mounted, but I'm sure that even those cards don't sound that bad, especially since even my cheap hifi CD player does sound better, than the Focusrite. The headphone amp of the Presonus wasn't very good, but it didn't colour the sound that much and unfavourable as the Focusrite does. Unfortunately I didn't test the sound quality of the Presonus outputs. Regards, Ralf _______________________________________________ Linux-audio-user mailing list Linux-audio-user(a)lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-user