Balancing act

At the moment everything seems a bit like a balancing act. First on a physical level, as I’m currently recovering from surgery one of the things I have to learn again is to find my balance, literally. While recovering I can’t do very much hobby stuff in the analogue domain so I swayed a bit to the digital domain again.

About 6 years ago I bought a Mixbus 32C license but found myself using Ardour more and more. During the pandemic I took a subscription and from then on I basically started using Ardour exclusively. Still remember the first time I opened up Ardour back in the 00’s, to me it was intimidating, daunting, what did all those buttons and sliders do? But like with more things in life, sometimes you just fathom the seeming complexity of something, call it an eye opener, and then you’re like, why didn’t I start using Ardour right from the beginning?

Now Ardour is my DAW of choice. It’s running on Debian 12 with a Liquorix kernel on my old, trusted BTO and I’ve never had such a stable setup before. Yes, Debian, after 14 years of Ubuntu that has become a balancing act too. The more applications are moved into Snap the more it alienates me from the OS. While I understand the concept of self-contained applications, it’s part of my job, I don’t think this concept has a real purpose on a desktop OS. It adds another layer of complexity and makes communication between applications harder. Whole different story for another time.

Ardour 8.0 has just been released and I can wholeheartedly recommend it. Installing and setting it up is a breeze and even on my old BTO it runs like a charm. The only restriction is that I can’t use too many Dragonfly Reverb plugins within a project but once I give in to my GAS to get a Framework notebook that will be resolved too.

Balancing act


You think you have it all configured right, all common DKIM checks on the interwebs agree with you but still you receive replies prepended with [DKIM ERROR]. You dig and dig, find out that apparently only one major mail server vendor gives back those errors, but no real answer or solution.

Picked up the gauntlet (after having smelled the glove) and tried a mail to the mail admins with zero expectations of getting an answer back. But no, got a reply within a day! And guess what. No it’s not my DKIM configuration. It’s my private key. It’s too secure. No, for real. This major vendor errors out on DKIM keys bigger than 2048 bits:

DKIM: permfail key too large ( s=dkim

So if you run into this and you’re using a 4096 bits DKIM key at least now you know a possible cause of this behaviour.


New modem

A while ago I received a new modem from Ziggo since they’re switching to DOCSIS 3.1. Didn’t have the time to replace the old Ubee UVW3200 modem but this morning I was forced to do so because the lease had expired and Ziggo had decided to give me a new WAN IP address in a network segment with no internet.

After replacing the Ubee with the Sagemcom F3896LG-ZG I had no internet though. I did have a green LED lighting up our meter cupboard and apparently that indicated the modem was in bridge mode. The Ubee was also working in bridge mode so that could very well be possible. Quick search revealed I had to call Ziggo, have them disable bridge mode and then I could put it in bridge mode myself again. So I called, Ziggo disabled bridge mode and a few minutes later I still had nothing. No option to enable bridge mode. So I called again. Apparently in some regions the bridge mode option doesn’t show up so Ziggo enabled bridge mode again. Green LED reappeared after a while and tada, my router received a fresh new WAN IP address and there was internet again.

So if you run into similar issues when replacing your Ubee that was put in bridge mode by Ziggo with the new Sagemcom modem, call them. Modem works good now, it does use a bit more power (36W vs 24W for the Ubee) but a bonus is that you still have remote access to the modem which was not possible with the Ubee. And like the Ubee everything else but the modem functionality is disabled so it probably needs less than 36W at the moment. I’ll hook it up to a power monitoring smart plug to find out.

New modem

Moved to Hetzner

After a great tip from dvzrv with regard to hosting all my stuff I recently moved everything to an instance at Hetzner. Main reason why I chose for Hetzner is that they allow you to run your own mail server. First I moved my mail setup and last week I moved the rest. It’s great that I don’t need a mail gateway anymore and it’s always good to move to a more up to date OS.

So my old instance at Fuga is switched off now. After having it backed up I will delete it with a slight pain in my heart, I have the tendency to grow attached to virtual instances. Something with pets and cattle. I’m inching more towards the pet side I guess.

Moved to Hetzner

rtcqs v0.5.2 released

After some thought and having updated the system configuration wiki page I decided to remove three checks from rtcqs. First to go was the background processes check. It checked for two processes that are not used anymore and these days I can’t think of an ubiquitous piece of software that could wreak so much havoc that it needs to be checked for. Second to go was the system timer check. Lore says that in order to achieve accurate MIDI timing one needs a kernel with a clock frequency of 1000Hz. But Linux audio software has been using the snd-hrtimer kernel module for years now which is way more accurate than those measly 1000Hz. This setting is really not needed anymore, same goes for echoing values to /dev/rtc or /dev/hpet max user freq values. Really, using the snd-hrtimer module together with a tickless kernel gives you way more accurate timing than when using a 1000Hz clock frequency. Don’t believe it?

jeremy:~$ grep timer /proc/asound/timers
G0: system timer : 4000.000us (10000000 ticks)
G3: HR timer : 0.001us (1000000000 ticks)

First line is the system timer, it’s 4000 microseconds which corresponds with a kernel clock frequency of 250Hz. But look at the line below, it will automatically pop up as soon as you start a modern Linux audio application that does MIDI. You see that? 0.001 microsecond. That corresponds with a clock frequency of 1.000.000Hz. That’s already a 1000 times more accurate than using a system timer of 1000Hz and this HR timer set at this frequency is available regardless which clock frequency your kernel is using.

Now we got that out of the way, I also removed the max user watches check. It shouldn’t have been there in the first place, I should be the one to know because I asked the gurus about it back in 2011 at LAC2011 in Maynooth. I got no response. For a reason, it’s simply unrelated to increasing the performance of your Linux workstation. So 11 years later it’s good riddance.

The power management check has been improved a bit. Instead of checking the mode and owner of the /dev/cpu_dma_latency device node rtcqs now simply checks if the user running rtcqs has write permissions on that device node. And Robin made it clear to me that even after 15 years or so of running Linux and working with Linux exclusively I still haven’t internalized the idea that Linux doesn’t need a reboot as long as you didn’t touch your kernel.

The tkinter GUI got a promotion, it’s the default GUI now. I’ve demoted the Qt GUI, to the point where it has become a beta feature. The GUI is fully dynamic now, if I add or remove checks to the main rtcqs module I don’t have to bother with the rtcqs_gui module. Maybe it’s getting time to wrap the rtcqs module up in a class.

Other things that got added with this release are a desktop file and two files to facilitate Python packaging. Yes, rtcqs is available on PyPi too as of now, one pip install rtcqs away. These features were requested on the rtcqs project issue tracker in order to facilitate packaging rtcqs for Arch. So if you have a request regarding rtcqs, or run into an issue with it, or spot inconsistencies or just plain false information in the output rtcqs provides, please let me know! Raise an issue at the Codeberg project issue tracker or discuss this release at the forum.

rtcqs v0.5.2 released

rtcqs v0.4.2 released

This release comes with a new Power Management check which checks if the audio group has read/write permissions on /dev/cpu_dma_latency. If your user is a member of the audio group and permissions are set for this group then DAW’s like Ardour and Reaper can open this file as your user, keep it open and control power management this way. This allows a user to prevent CPU sleep states for example so your CPUs are always on and instantly available which could lower the chance running into xruns.

Ardour CPU DMA latency setting Under Edit – Preferences – Performance

This release also introduces a new basic and simple tkinter-based GUI. The Qt GUI does look fancy but to use it it also needs a fancy amount of dependencies. When building binaries with PyInstaller the result of the Qt GUI is a whopping 130MB package while the tkinter version stays below 12MB.

rtcqs tkinter GUI

Future plans are to get rid of some checks:

  • Max user watches as it’s not related to the overall performance of your system
  • System timer as it’s not relevant anymore, rtcqs already checks for the more relevant stuff (high res timers and tickless kernel)
  • Background processes as it’s merely a placeholder which checks for two processes that don’t exist anymore on modern systems

I’m having my doubts about swappiness too as it’s not really applicable anymore for modern machines. But I’m curious if it still applies for smaller systems like RPi’s for example. I’d like to add a filesystem mount option check, for Ext it would check if the filesystem is mounted at least with the relatime option or even noatime for example. And maybe a disk scheduler check but I’m not conviced yet that it really makes a difference.

The new release and binary packages of rtcqs and rtcqs_simple_gui can be found on the Codeberg repo:

rtcqs v0.4.2 released

Using Home Assistant with IR controlled devices

When my stereo amplifier stopped working I could’ve bought a new one but after a quick look inside I was pretty sure the damage was minor so I brought it to a repair service. When I could pick it up again not only were the costs way below the price of a new amplifier but the repair service basically did a full recap with good quality capacitors so not only will it last another decade or two it also still sounds great.

But since this is a pre smart era device it only came with a bulky IR remote, so no possibility to control it via Wi-Fi. I bought a cheap Wi-Fi remote control device that could be flashed with Tasmota and integrated it with my Domoticz setup. Then we got a new thermostat that worked with Domoticz initially but after a firmware update it stopped working. With Home Assistant everything worked except for the IR remote control so for a while I used both solutions.

Not ideal so I dug a bit deeper to get the IR remote control to work with Home Assistant. Since user stories on this matter are pretty much non-existent here are the steps to get a similar solution going on your Home Assistant setup. Be warned that this is not a step-by-step walkthrough, I’m assuming you know how to flash ESP devices, that you know your way around Home Assistant and Tasmota and that you have your own MQTT server running.

First you will have to acquire a Wi-Fi remote control device that can be flashed with Tasmota. I got one from Amazon similar to this unit. Flashed it over the air with tuya-convert. Next step was to add the Pyscript HACS integration to Home Assistant. Then I added the following Python script wich I named to the pyscripts directory.

#!/usr/bin/env python3

import paho.mqtt.client as mqtt

mqtt_server = "localhost"
topic = "ir_remote01"

# IR codes
ir_codes = {}
ir_codes['stereo_protocol'] = 'NEC'
ir_codes['stereo_volume_down'] = '0xE13E31CE'
ir_codes['stereo_volume_up'] = '0xE13E11EE'
ir_codes['stereo_off'] = '0xE13E13EC'
ir_codes['stereo_on'] = '0xE13EA45B'
ir_codes['stereo_tuner'] = '0xE13EBB44'
ir_codes['stereo_aux'] = '0xE13ED926'
ir_codes['stereo_cd'] = '0xE13EA15E'
ir_codes['stereo_video'] = '0xE13E43BC'

def send_ir_code(action=None, id=None):'irsend: got action {action} id {id}')
    ir_protocol = ir_codes[f'{id}_protocol']
    ir_code = ir_codes[f'{id}_{action}']
    ir_payload = f'{{"Protocol":"{ir_protocol}","Bits":32,"Data":"{ir_code}"}}''irsend: sending payload {ir_payload}')
    mqtt_client = mqtt.Client()
    mqtt_publish = mqtt_client.publish(f'{topic}/cmnd/irsend', ir_payload)

What this script does is sending a message over MQTT to the IR remote control, the IR remote control then converts this message to an IR signal and transmits this signal. The script needs two input parameters, action and id. These parameters are made available to the script through pyscript. The Python @service decorator makes the script available as a Service in Home Assistant.

With this Service working I can add it to a View. I used a Grid card for this and added Buttons cards to this Grid.

The Grid Card Configuration looks like this.

Added a Name, an Icon and set the Tap Action to Call Service. As a Service I could select Pyscript Python scripting: send_ir_code and as Service data I entered an id and an action as a dictionary, so {id: stereo, action: on}. Did this for all the other actions and now I can control my pre smart age stereo in a smart way.

Using Home Assistant with IR controlled devices

rtcqs released

rtcqs v0.3.1 is now available on Codeberg and Github. rtcqs is the continuation of the realtimeconfigquickscan project but then rewritten in Python. It comes with a Qt GUI and a few extra checks.

Dear all,

I’d like to announce rtcqs, the continuation of the realtimeconfigquickscan project. It’s a port to Python with some added extra’s, like a Spectre/Meltdown mitigations check and a Qt GUI. It has the approval of the original author of realtimeconfigquickscan to whom I owe a debt of gratitude, not only for the original code but also for his helpfulness with the continuation, or maybe even evolution of the project.

So check it out, indulge me with bugs, issues, improvements or any other useful feedback on the Codeberg repo which you can find at at

Happy system tuning and happy holidays!


While setting up a solution to fully automate the deployment of SSL certificates at work I piggybacked on the flow and focus to rewrite the realtimeconfigquickscan Perl code in Python. As part of the certificate deployment project I wrote an application to decrypt, re-encrypt and base64 encode PFX files so they can be uploaded to a vault solution. This way I ran into PySimpleGUI which enabled me to quickly put together a nice looking Qt GUI.

rtcqs main window

The code could be more terse and probably contains some typical non-programmer idiosyncracies. First improvement will be to make the code more dynamic so the GUI gets generated instead of using hardcoded values like it does now. And I’d like to add a power management check but then I first need to read up on that subject. There are also some checks that might need some more scrutiny like the swappiness and max_user_watches checks to verify if those checks are really needed for a real-time audio environment.

rtcqs released

And what about Linux audio?

Yeah, what about it? Well, not much really. I have acquired the domain name since that is more practical when it comes to DNS changes as I am one of the root admins of the servers. When it comes to making music I’m still exclusively using Linux but I’ve shifted to a monolithic approach. I bought a Mixbus32C license a couple of years ago, clicked on ALSA as Audio System and never looked back.

My interest also shifted to the analog domain. Having a busy job in the digital domain I found myself more and more avoiding computers outside of work. In the same time I got more involved in making music and I’ve also dived into the world of analog electronics. I’ve always wanted to know how guitar effects and tube amplifiers work so I just started building effects a few years ago and by now I can also bias my own amps and do simple mods. I’m also learning how to get the most out of my guitars when it comes to intonation, action, pickup height and electronics, that kind of stuff. It’s very gratifying to be able to do those kind of things yourself, to pick up a guitar you’ve serviced yourself and that it plays and sounds like a dream.

So next up is building my own amp, got all the parts and I have two weeks off around Christmas so hopefully I can start the new year with a screaming solo from my own amp. Building my own guitar would be awesome too. A complete DIY setup, I’d love that.

And what about Linux audio?

New job

Working at home during the Intelligent Lockdown got me thinking about a lot of stuff, including my job at Cyso. I started weighing the many positive aspects against the negative ones and unfortunately the balance tilted too much towards the negative side. So when I got contacted by Evidos I decided to bite the bullet because their offer just ticked so many boxes. Started there in August and I’m now at the point where things are starting to roll. I’m hired as a cloud engineer but as a jack of all trades I already find myself meddling with all kinds of things. Besides maintaining the current cloud platforms, which are mainly used for testing purposes, I’m also heavily involved in the upcoming migration of the current setup into the cloud. And I offer a fresh outlook on a wide variety of subjects that could be done better in my opinion. Think of monitoring, automation and security but also how operational work could be organized better, how existing processes could be improved and I’ve made a start with setting a proper standard for documenting all the things we do.

Evidos itself is a company that does digital signing. Think of all kinds of contracts, deeds or other official documents that need a signature. So no need to go to a notary office, estate agent or your new employer physically, just add your signature in a digital way to the official documents and end up with documents that have been fully signed by all involved parties with a solid judiciary basis. This just saves a lot of time, paper and physical encounters that should be avoided as much as possible these days.

For me this means improving my skills when it comes to encryption standards and methods, security awareness and compliancy. And a great opportunity to make good use of the knowledge I’ve amassed over the years. So far I’m happy about the decision I’ve made, it’s quite a step to change jobs, especially when you already work for a great company with a permanent contract and also given the current circumstances. But sometimes you’re just forced to step back and reconsider. I’m glad that happened, I’m regaining my enthusiasm to work with Linux and open source software in general which is a good sign and I’m starting to find more focus and peace in my current job. A good thing, not just on a professional level but also on a personal level.

New job