Analog Sound + Digital Synths

Creating analog or retro sounding synth patches with digital wavetable synthesizers can be quite challenging. In this article I want to present to you five simple tips for doing just that in Xfer Serum. If you prefer a different wavetable synth, e.g. NI Massive X or Arturia Pigments, you can still go through these tips and apply them to your synth of choice. I'd recommend to try these tips out in your DAW while reading this article.

If you are interested in buying high-quality presets for Serum, checkout my Cyberpunk Preset Pack. It has a lot of analog and organic sounding synth patches with lots of detail and depth. 

Tip #1

Use classic wavetables: Sawtooth, Triangle or Pulse (PWM). In Serum you have multiple variations of them in the „analog“ wavetable folder, e.g. Basic Mg, DS Saw and Tri, PWM Juno or PWM Mini. The next step after picking wavetables for OSC 1 and 2 is to slightly detune both oscillators (with the fine tune setting at the top of the OSC menu). Start with +/-1 cent and slowly increase the detuning to hear how the sound becomes thicker and changes over time. In most cases +/- 1 to 7 cents are enough for one oscillator but if you want to make the sound really dense you can increase the detuning to approx. +/- 8 to 15 cents. Everything above that sounds really dissonant but in some cases you might even want to do exactly that.

Tip #2

Use classic lowpass filter designs (e.g. Serum: MG Low 12 or 24, Low 12 or 24, French LP, German LP, Scream LP). Almost all classic analog synths only have basic filter designs like lowpass, highpass and bandpass and therefore it is not recommended to use exotic digital filters when trying to emulate an analog sound. Most analog filters have a 12dB/oct or 24dB/oct slope and in Serum you can choose from several variations in the filter menu. To get as much character out of the filter as possible, I’d recommend boosting the resonance and drive quite a bit. By modulating the cutoff frequency and the resonance amount with an envelope or LFO you can then create motion and add definition to the sound. Note: Most of the time it sounds best to route all oscillators and the noise through this filter. 

Tip #3

Add noise to the patch. The most common noise generators in analog synths are pink and white noise generators. White noise is the more versatile type of noise because it is brighter and doesn’t add too much rumble to your sounds. In Serum you can find quite a few variations of it in the noise menu under „analog“. White noise can be a very good addition to pads and leads that need more texture and organic feel but you should be careful when adjusting its volume because too much of it can make a preset sound muddy or undefined. By modulating the volume, pan or „pitch“ with an ENV or LFO you can also add motion to the noise and mix it in better.

Tip #4

Create imperfections to give the patch more detail. Most classic analog synths had specific characteristics / imperfections like slightly detuning oscillators or subtly changing envelope settings that make them sound more lively and interesting. You can imitate that and enhance your synth patch with subtle modulations on various parameters.
Here a few examples:

• Slow LFO modulation on oscillator fine tuning (just a few cents)
• Slow and subtle LFO mod on filter cutoff frequency and resonance
• For PWM wavetables: Slow LFO / ENV mod on Pulse Width (Serum: Wavetable Position - "WT Pos")
• Subtle LFO mod on ENV parameters, e.g. Attack or Decay Time

Change the LFO rates and shapes as well as envelope settings for these modulations and listen to their effect. Subtlety is key here but in some cases you might also want to exaggerate some of these modulations to create an interesting characteristic. It is also up to you how many modulations you add to your patch, but always be aware of the CPU load.

Tip #5

Enhance the patch with effects to make it even richer. There are three versatile effects in Serum that are most effective at making your patch sound more analog and those are distortion, chorus and delay:

• Use analog distortion to add overtones to your patch. It can even work for clean sounds by adding just a little bit of drive and mixing it in just a few percent. Adding a lowpass or bandpass can also help to make the sound smoother. The distortion types that work best to saturate your patch a little bit in my experience are Tube, Soft Clip, Stomp Box and Tape Saturation. If you want the "analog distortion" to be more aggressive Diode 2, Zero Square and Asym can get you there.
• Use chorus to create a classic lush pad or lead sound. Use a slow to medium fast rate, medium depth and low to medium feedback. If you want to have a really lush and wide sound go over 50% wet but be aware that the sound then increasingly loses its mono compatibility. In most cases it works fine for pads and leads but it’s always better to check your mix in mono.
• Use delay to add depth to the preset. You can add subtle rhythmic imperfections to it by slightly delaying the left and right side and filtering the delay to put more focus on the mid frequencies also helps to make it sound more analog. Leaving left and right at the same delay time (mono delay) can also work quite nicely. 

This is just the beginning

You see there are several ways to make your Serum patches sound like they are coming from an analog synth and these are just the essential steps. You can always go deeper and create more nuanced modulations and also modulate one modulation source with another… The possibilities are near endless and it’s up to the user to create innovative and interesting sounds. 

If you are interested in buying high-quality presets for Serum, checkout my Cyberpunk Preset Pack. It has a lot of analog and organic sounding synth patches with lots of detail and depth.