Noisy Focusrite Scarlett and how to fix it

Having noise issues on your external USB audio interface when connected to a desktop PC and powered studio monitors? Chances are you’re having issues with your grounding… Make sure you are using balanced cables, meaning three wires (two phases + ground) to connect your speakers to the output of your interface.

I recently spent quite a few hours chasing down an extremely annoying crackling hum on my audio setup because of that. No ground loop, all devices connected to the same circuit, I even hooked everything up to an online UPS so I get perfect sine voltage but to no avail. When connected to my main workstation there was a noticeable and extremely annoying background noise on my monitors that wasn’t there when I plugged the Focusrite Scarlett 2i2 into my notebook or mobile phone via an USB OTG adapter. Heck, it wasn’t even there when I plugged it into an HP Z600 workstation that is sitting right beside my main computer, all connected to the same UPS, ethernet switches and whatnot…

Turns out I used unbalanced cables from the Scarlett to the monitors and apparently the MSI X99S mainboard (or maybe the power supply?) in my primary desktop computer has for some reason quite a bit of noise on the ground of the USB bus. Or something like that – I didn’t bother to get an oscilloscope to verify.

Swapping the cables from TS to proper TRS (tip-sleeve “mono” to tip-ring-sleeve “stereo” aka balanced) fixed it and everything sounds perfect, no matter what computer the interface is connected to.

HP ProLiant: 601 – diskette controller error, what it really means

I recently got this puzzling error message on an HP ProLiant Server: 601 – Diskette Controller Error with the system just stopping at the BIOS, no way to enter the maintenance menu or continue booting. Well that’s odd, I though… being a BL460c blade server. All the documentation I could find online suggested it’s a defective floppy drive, or loose cabling… which a blade server doesn’t have.

Ok, so it’s a legacy error message. Maybe the BBWC? Nope. Backplane module then? Nope. The disks? Nah. The fucking SD card module? Not even that… Well, let’s try a system reset them using the DIP switches. Nope. Switching to backup ROM and booting with that one… Doesn’t work either. Well, fuck. Remove all the mezzanine cards – basically the system stripped down to the bare minimum. Still the same error.

About three hours later… Being the only removable part left, I figured I remove the CMOS battery and check it while I’ve it remove. Turns out it’s dead. Replace it with a new CR2032 button cell and voila – system boots again as if nothing happened.

So there you go… 601 – diskette controller error apparently really means: your CMOS battery is dead, better replace it. Even though the documentation says otherwise.

Dear HP: Fuck you. I want those hours of my life back.