Holy Bot

Bedroom music production, gaming and random shit



In Voltage

I didn’t want to dive into the ocean of modular synthesis. For may years I resisted. I thought the practice was all about experimenting and jamming – all about the live session in itself. And for me, the things that come first in all of this, are songwriting, composition, arrangement, structure, mixing, and postproduction such as mastering.

And while I enjoy sound design very much, and regard it as an important part in the making of music, I thought Eurorack modular systems primarily made noises that was hard to integrate into more conventional tracks. And then it’s not possible to save presets.

But now I’m thinking: why not have both? I can still do my old routines, and at the same time care for a little ecosystem with an ephemeral nature on the side. I could set limits.


So I’m building a basic synth voice, something in that direction. The modular rack is made of dedicated modules (more or less) and has many modulation possibilities. It kind of goes like this: VCO > MIX > VCF > VCA > ENV > LFO.

I don’t want to use multifunctional toolboxes, such as Expert Sleepers Disting or advanced generators as Make Noise Maths to begin with. I don’t want a computer to do everything – that would defeat the purpose of a modular system (although a couple of combined utility functions are alright, like Mutable Instruments Kinks or Intellijel Triatt ). I’m not putting a self-contained, semi-modular synth – like a Moog Mother-32 or an Arturia MiniBrute 2 – as a starting point, because I want building blocks; different exchangeable modules. (I’m, however, using an Elektron Analog Keys to control everything and then some.) For the modular system will grow, evolve organically, and stuff will be supplemented or replaced.

From the get-go, the the modular is mainly Doepfer, but it will be customized with other equivalent modules or upgrades. I’d like to say I’m expanding slowly to get a chance to thoroughly understand the modules and how they interact with each other, but to tell you the truth, this configuration has really exploded. But I guess, and hope, it will cool down. It takes time and perhaps it’s the process per se that is the point.

Another agenda is to acquire used modules on the secondhand market, as far as possible. I want to be able to try out and then sell, if it doesn’t fit without losing too much money. This approach has been working great with the exception of a friend of mine whom is building a uBraids for me.

P.S. Ableton Live 10 is officially released today.


Tips for the monotribe

The Korg monotribe is a desktop analog monophonic synthesizer with an additional three preset drums sounds. Its sound is warm and rich but quite clicky and noisy – although I think I prefer this timbre over the newer volca series. The monotribe was released in 2011 and is now discontinued.


How to Silent the VCO When Processing External Audio

The synth has an audio in port to feed external audio into 12 dB/oct lowpass filter (which uses the same circuit as the classic MS-10/MS-20). The crux is that the synth engine must be triggered to run the filter, meaning it’s not possible to process external audio solo (without being modded). But the LFO can modulate the oscillator so that it becomes nearly inaudible. The workaround below is not exactly neat, but should do the trick. On the monotribe, do as follows:

  1. Press PLAY button and then REC.
  2. Set RANGE select switch to WIDE and press the highest key on the RIBBON keyboard during the whole sequence.
  3. Set EG to GATE.
  4. Switch TARGET to VCO.
  5. Set MODE to 1SHOT.
  7. Set LFO RATE knob to minimum speed and INT. to maximum depth.
  8. Select TRIANGLE WAVE on modulation waveform WAVE.

How to CV Control the monotribe with the Analog Keys’ Keyboard

OS version 2.11 allows the SYNC IN connection to be used as a pitch CV/gate input. This makes it possible to control the monotribe with an external keyboard or sequencer (which is great because the ribbon keyboard is almost impossible to play). There are many ways to do this, but the theory is the same: send CV and gate via a TRRS 4-pole mini jack – where gate is tip and CV the second ring.

Now I got an Elektron Analog Keys which can send both tip and ring from the same CV output, but to do that to the monotribe I’d need a special cable (sort of TRS to TRRS) and I haven’t soldered any yet. So until then, I hacked a workable cable with many different pieces I found laying around (e.g. the composite video cable was provided with a TV I acquired last year). Again, you can build this patch cable more streamlined, but here’s my solution:

  1. Connect a composite video cable to SYNC IN on the monotribe and connect a RCA connector, white male to white female and red male to yellow female. On the other end, connect a pair of adaptors, RCA female to mono 3.5 mm mini jack male and then another pair of adaptors, 3.5 mm mini jack female to 6.3 mm jack male and plug white in CV AB and red/yellow in CV CD on Analog Keys.
  2. While this setup only uses the tips, and demands both CV ports on Analog Keys, set CV A to Gate, V-Trig, 5.0 V and CV C to Pitch V/oct, C 3, 1.000 V, C 6, 4.000 V. (CV B and D are not used.)
  3. Download and install System Updater 2.11.
  4. Prepare the monotribe as described in the documentation that came with the download package. Activate CV/GATE mode, set the Pitch CV curve to V/oct and GATE polarity to high.

P.S. It’s also possible to create a feedback loop by feeding the headphone output back into the monotribe’s audio in. This will render a mild thickening, and if you have some kind of attenuator on the feedback signal path, you can dial in some overdrive too.

CV on Analog Four

If you got an Elektron Analog Four (or Analog Keys) and devices that can be operated via CV (control voltage) and Gate trigger connections, here’s how to do it, e.g. connect Moog Minitaur and Arturia MiniBrute to sequence, automate and processes them on Analog Four.

1. Connect a stereo ¼” (female) to CV Output A and B on Analog Four, and dual mono ¼” to Pitch CV (tip) and Gate (ring) of the Minitaur.
2. Connect Audio Out on Minitaur to Audio Input Left on Analog Four.
3. On Analog Four, select track Trk 1.
4. Select Osc 1 > IN L.
5. Pass all frequencies on 2-pole ladder filter: Filters > FRQ 127 and RES 0, and 2-pole multi mode filter: Filters > HP2 > FRQ 0 and RES 0.
6. Set the envelope on Amp > REL INF (if you don’t plan to use the Osc 2, sub oscillators or filter self-oscillation of the Analog Four).
7. Select track CV.
8. Set CV > CV A > TRK > TR1 and CV > CV B > TRK > TR1.
9. Select CV A configuration page, and set:

NOTE 1 > C 3
VOLTAGE 1 > 1.448 V
NOTE 2 > C 6
Voltage 1 > 4.634 V

10. Select CV B configuration page, and set:

LEVEL > 5.0 V

11. Connect a stereo ¼” (female) to CV Output C and D on Analog Four, and dual mono ¼” to Pitch (to VCO) (tip) and Gate In (ring) of the MiniBrute.
12. Connect Master Out on MiniBrute to Audio Input Right on Analog Four.
13. On Analog Four, select track Trk 2.
14. Select Osc 1 > IN R.
15. Pass all frequencies on 2-pole ladder filter: Filters > FRQ 127 and RES 0, and 2-pole multi mode filter: Filters > HP2 > FRQ 0 and RES 0.
16. Set the envelope on Amp > REL INF (if you don’t plan to use the Osc 2, sub oscillators or filter self-oscillation of the Analog Four).
17. Select track CV.
18. Set CV > CV C > TRK > TR2 and CV > CV D > TRK > TR2.
19. Select CV A configuration page, and set:

NOTE 1 > C 5
VOLTAGE 1 > 1.004 V
NOTE 2 > C 8
Voltage 1 > 4.004 V

20. Select CV D configuration page, and set:

LEVEL > 5.0 V

Set up the old king SH-101

If you got a Roland SH-101, the set it up like this:

1. Connect a stereo ¼” (female) to CV Output A and B on Analog Four, and dual mono ¼” to CV In (tip) and Gate In (ring) of the SH-101.
2. Connect Output on SH-101 to Audio Input Left on Analog Four.
3. On Analog Four, select track Trk 1.
4. Select Osc 1 > IN L.
5. Pass all frequencies on 2-pole ladder filter: Filters > FRQ 127 and RES 0, and 2-pole multi mode filter: Filters > HP2 > FRQ 0 and RES 0.
6. Set the envelope on Amp > REL INF (if you don’t plan to use the Osc 2, sub oscillators or filter self-oscillation of the Analog Four).
7. Select track CV.
8. Set CV > CV A > TRK > TR1 and CV > CV B > TRK > TR1.
9. Select CV A configuration page, and set:

NOTE 1 > C 3
VOLTAGE 1 > 0.986 V
NOTE 2 > C 6
Voltage 1 > 3.956 V

10. Select CV B configuration page, and set:

LEVEL > 5.0 V

Note that the voltage levels are roughly set. Also bear in mind that it seems that some split cables use left for tip and right for ring, while others directly contrary.

Tune Other Gear

If you got other gear, then connect a tuner to the audio output, select CV A configuration page and start with:

NOTE 1 > C 3
VOLTAGE 1 > 1.000 V
NOTE 2 > C 6
Voltage 1 > 4.000 V

Then just tweak the voltage settings – 1 V per octave in the mid range – according to the tuner, this usually works.

Lastly, don’t forget to check all four voices on the KIT > POLY CONFIG > VOICES to use Analog Four as an analog polysynth while using the two external sound sources of your choice.

P.S. I totally missed this, but this blog, Holy Bot, turns four years today, yay!

FM à la Analog Four

One of my favorite synths is the Analog Four, and with the OS update 1.22 a while back, Elektron added new LFO synchronization modes and destinations and made this synth even more awesome. (If I only could take one of my synths to a deserted island, it would be the Analog Four.) Anyway, in short that means I’m now able to apply pitch tracked LFO FM behavior.

Here’s a way to start (not rules):

  1. Set triangle (as a substitute for sinus) waveform on an oscillator.
  2. Open up both filters.
  3. Set the LFO speed to any multiples of 16.
  4. Set the LFO multiplier to over 512 and synchronize it to the oscillator you’re working with.
  5. Let the LFO restart when a note is played on Trig Mode.
  6. Choose sinus as the LFO waveform.
  7. Set frequency or pitch modulation to the oscillator as LFO destination. (Also try different destinations later, like the filter frequency.)
  8. Set depth of the LFO modulation (or, if you’re using the first oscillator, let the second assignable envelope control this).
  9. If you use Depth A in the step above, then try to fade in or fade out the modulation.

Also, there’s a few videos on YouTube describing these methods, like this, which is a good walkthrough, even though it’s a bit unfocused and lengthy.

Mixer Setups

I wrote about my mixer some time ago, and you might wonder how it’s connected and how recording is done.

There are several options to route the signal flow of the Mackie 1202VLZ4, although my setup is kind of generic and should work for many different rigs. It goes like this: The DAW connects to the audio interface via USB, with communication in both directions. The audio interface, through stereo outs, connects to left and right audio ins of the monitor speakers. The main stereo outs of the mixer routes to the audio interface via line in pair. All instruments and mic go to different line ins of the mixer.

DAW > Audio interface > Monitor speakers
DAW < Audio interface < Mixer < Instruments and mic

In this setup, the main stereo out of the mixer is routed to the line in pair of the audio interface, and the monitor speakers are connected to the stereo output of the audio interface.

If you prefer to have all audio signals (software and hardware) going through the 1202VLZ4 mixer, you should be able to connect the XLR main outs to the monitor speakers, and route the TRS second main outs back to the line in pair of the audio interface. Also, on the 1202VLZ4, there are control room outs with selectable source (main mix, alt 3-4 stereo bus, soloed channels, or the tape input) that you can use to route to the line in pair of the audio interface.

Generally when recording in a DAW, you just create an audio track, and select line in of the audio interface as audio input. You can choose to record in stereo or mono. Don’t record too hot, keep some headroom.

Sometimes I miss being able to record to several audio tracks simultaneously (multichannel recording). Although with Overbridge (Elektron’s integration software) the Analog Four – which only has a stereo output – can now output all four tracks individually to Ableton Live. In that way it can function as a multi-tracking USB sound card of sorts.

My Mixer

During 2015 my hardware synth collection grew considerably while the audio interface still had limited input connections. This led to an investment not of a bigger audio interface, but of an analog mixer.

By then I was looking for a no-frills compact mixer that was able to make a clear, pristine mix with high headroom and low noise. I had no need for neither built-in effects nor USB connection, but wanted a small footprint mixer and great sound quality. So I got the Mackie 1202VLZ4.


Even if I’m using the mixer merely as a patch bay, more or less a set and forget scenario, it’s a quite creative mixer. For example, the mute/alt 3–4 function serves both as muting and signal routing (where it acts as an extra stereo bus). This means that the alt bus can be used to route shit through serial effects as a stereo channel, which in turn opens up for further possibilities.

The 1202VLZ4 also has channel insert, and I’m now thinking of getting some effects, perhaps something from Strymon or Eventide.

In brief, I’m happy with the mixer, but I honestly haven’t had that many analog mixers, so I can’t really compare this one to others. Some say the 1202VLZ4 offers bang for the buck featuring Mackie’s flagship Onyx mic preamps and so on, but I, for one, can only say it works well.

P.S. There are times when I would have preferred an audio interface with like 18 input connections that could be mixed and recorded on separate tracks inside the DAW, true. But most of the time I only need the 4 voices of the Analog Four to be recorded individually, and with Overbridge it is possible already.

Analog Synth Filter Test

I’ve made a low-pass filter test of sorts. Very unscientific though.

I ran an old monosynth through three popular modern synths: Arturia MiniBrute, Moog Music Minitaur and Elektron Analog Four.

The sound source is the Roland SH-101 with both waveforms plus the sub-oscillator simultaneous triggered on C1. The gate signal controls the VCA, envelope and modulation are turned off, and key follow knob is set to 100%.

The audio signal is sent to the filter circuits of the different synths. The test pattern is defined as follows:

  1. A “clean” tone feeds into the filter for a few seconds, with frequency cutoff set to 100% and resonance at 0%.
  2. Manual filter cutoff sweep with resonance at 0%.
  3. Manual filter cutoff sweep with resonance at 50%.
  4. Manual filter cutoff sweep with resonance at 100%.

First off is the SH-101 internal 4-pole 24 dB per octave low-pass filter.

Next up is this unmodulated audio signal going into the MiniBrute and processed with the multimode Steiner-Parker filter, set to 12 dB per octave slope in low-pass.

On the higher resonance level, self-oscillation occurs and the volume peaks. (I had to put a limiter at -6 dB threshold to keep the volume at bay). The filter sweeps follow the same order as earlier.

The second external filter in this test is the Moog ladder filter (4-pole 24 dB per octave low-pass) of the Minitaur. Again the filter sweep follows the same order as above. The volume level drops noticeably on the higher resonance settings.

The last filter is the Analog Four’s ladder filter, another 4-pole 24 dB per octave low-pass.

The audio signal pass through the synth’s second filter unaffected (the 2-pole multimode filter is set to 12 dB per octave high-pass with minimum frequency and no resonance).

Maybe I’m doing something wrong here, because the audio signal seems to loose some decibels both in the treble and in the bass. Anyway, the flattest response is obtained when resonance is somewhere around 25, not 0.

On the last filter sweep, the resonance is set to 85 (out of 127), because the self-oscillation is going crazy over 85, and only the filter sounds. And the volume raises dramatically.

That’s the test for what it’s worth, I know the execution leaves a lot to be desired. The input level of the synths differ some, which makes a comparison hard. I should probably mention that the audio signal is running through a Mackie 1202VLZ4 mixer before being recorded using high-grade Cirrus Logic converters. This might have some affection and coloring on the signal.

In the Thick of It

This blog is about music production and gaming. And I live in Stockholm, Sweden. You might now this if you’re following the blog. But did you know that I live in the same part of the city (Södermalm that is) as several of the famous Swedish manufacturers? Of course it doesn’t mean anything, there’s no synergy or anything, just a fun fact.

Teenage Engineering is only 240 m away. And I pass DICE, 1.8 km from home, every day going to work (some years ago I work at a news agency in the same actual building). Clavia is in the same area too, 1.1 km from home. Propellerhead Software is located 4 km, a bit further west, still on the same island. Moreover, Mojang is 2.7 km from home and 600 m from my job.

Only Elektron is located in the second biggest city of Sweden, Gothenburg (Göteborg), and Massive Entertainment is situated in the third biggest city, Malmö. SoundCloud started in Stockholm but moved to Berlin, Germany.

Maybe I forgot some companies, like Spotify and whatnot, however, it’s a small capital and a small country.


Blog at

Up ↑