Tandberg instrumentation recorder controlling a synthesizer

video upload by A Radiophonic Shed

"This Tandberg Series 115 instrumentation recorder is a scientific logging device from the 1970s.
Voltage changes detected from scientific instruments are recorded as frequency-modulated signals to four separate tracks on ¼" magnetic tape. When the tape is played back for analysis, those same voltages can be examined - replaying the experiment.
Here we have recorded 1V/octave pitch voltages from a keyboard, and now we're replaying those same voltages into a modular synthesizer - all the sound is coming live from the synthesizer, it isn't an audio tape recording.

More details: https://shedsynth.wordpress.com/2026/..."

And a short video featuring the Tandberg as a VCO along with a full view of the front:

Tandberg 115 as a VCO – electronic music from old test equipment

video upload by A Radiophonic Shed

How's the Serenity?

video upload by cirtcele

"Quad reverse sigmoid chaos module with CV inputs, sync controls and mixed outputs
https://www.nonlinearcircuits.com/mod...

single 1U version - https://www.nonlinearcircuits.com/mod..."

"This module is a set of 4 reverse sigmoid chaos circuits, running at different frequencies, there are pots to feed each section into another and influence, sync – sort of, the action. There are also CV inputs for each section which affect the reset or crossover timing, for the faster ones the results are obvious. For the slower ones, give it a few hours.

The reverse sigmoid circuits are similar in concept to the mackey-glass based design used in the NLC Frisson, but are greatly simplified to a bare minimum of parts. Simply an integrator, two all pass filters and a nonlinear stage with two feedback paths. The nice thing about them is you can use any capacitors you like, so long as all three are the same, and the circuit will work with no other mods required. The sections in this module use 1uF, 10uF, 2x 1000uF in series (so 500uF) and 2x 2200uF in series (so 1100uF).

They work quite differently to the Sloth chaos circuits, with a number of ripples or rolls between each attractor, also the three outputs track each other, the faster ones are delayed by a few seconds, the slower ones by minutes. The intent of having 4 different circuits running together with pots to get them to influence each other is to have a module that can create longer tracks with many different but related musical events happening and, of course, weird delayed CV effects. Think of a band where the members all do their own thing but every now and then the sounds and patterns connect and achieve structure, which slowly scatters and reforms in new ways.

Feel free to change the 1uF caps to a higher or lower value, similarly for the 10uF. Stack capacitors on top of each other to get 20uF, or use Tayda 22uF caps and stack them. See pictures on pg6 for info on which caps to change. Make sure the capacitors have at least a 25V rating or higher.

If you want to use larger values than 1000uF and 2200uF, make sure they will fit on the PCB and/or thru the panel holes (1000uF on PCB are 10mm diameter, 2200uF panel holes are 16.8mm)

There are also two difference rectifier circuits which output complex mixes of the individual chaos circuits."

1U REVERSE SIGMOID
DESCRIPTION/USAGE

6hp

This module is a reverse sigmoid chaos circuit; it can be built to run as a fast or slow CV source, or even as an audio/noise source. This is a single version of the four chaos circuits in the NLC How’s the Serenity module.

The reverse sigmoid circuits are similar in concept to the mackey-glass based design used in the NLC Frisson, but are greatly simplified to a bare minimum of parts. Simply an integrator, two all pass filters and a nonlinear stage with two feedback paths.

The nice thing about this design is you can use any capacitors you like, so long as all three are the same the circuit will work with no other mods required. The capacitors are marked ‘C’ on the PCB, 1uF is a good mid-range value to install, but 10uF, 22uF are good too albeit much slower. Lower values than 100nF get you into audio rate territory. Make sure the capacitors have at least a 25V rating or higher.

This works quite differently to the Sloth chaos circuits, with a number of ripples or rolls between each attractor, also the three outputs track each other, the faster versions are delayed by a few seconds, the slower ones by minutes.

The Input expects a positive CV, negative going CVs won’t hurt but will have no effect. The CV signal feeds into the first all-pass filter stage via 10k and a diode, this is different to the method used on How’s the Serenity. On slower builds, using 10uF caps, the effect of the CV will be washed out to some extent. It will still have an effect but not as noticeably as on the faster versions.

WTV Synth (through echo)

video upload by Tim Kaiser

Logistic Maps and Analog Computing with Serge

video upload by La Synthèse Humaine

New Uses for Old Circuits Series

"New Uses for Old Circuits is a series looking at linear and nonlinear processes in the modular system.

In this video we look at the textbook example of a nonlinear and chaotic system - the logistic map. We explore how to use the Serge as an analog computer to take numbers and multiply, add, and subtract them, and further how to create a discrete feedback sequence from them.

Check out Greg Zifcak's website and his example of the Logistic Map: https://www.gzifcak.net/cefms/"

Nonlinearity And Feedback

video upload by La Synthèse Humaine

New Uses for Old Circuits Series

"New Uses for Old Circuits is a series looking at linear and nonlinear processes in the modular system.

In this video we look at simple feedback systems and explore linearity and nonlinearity. We see how basic audio feedback through a linear system (basically a volume knob) can accentuate or attenuate what is already present in a sound. But sending the feedback through a nonlinear system transforms the sound into something else entirely."

New Uses for Old Circuits 04: Studies in Linear and Nonlinear Systems

video upload by La Synthèse Humaine

New Uses for Old Circuits Series

"New Uses for Old Circuits is a series looking at linear and nonlinear processes in the modular system.

In this video we get right to the heart of the matter and discover what defines a linear system (and therefore what defines a nonlinear system). Linear systems are systems that obey the laws of homogeneity and superposition, whereas nonlinear systems are ones that break these laws."

New Uses for Old Circuits 03: Sources Of Inversion

video upload by La Synthèse Humaine

New Uses for Old Circuits Series

"New Uses for Old Circuits is a series looking at linear and nonlinear processes in the modular system.

In this video we go through every module in the Serge synthesizer to discover which circuits create an inversion at the output. As a result, we create perhaps the most boring synthesizer video on YouTube, but we also lay some important groundwork for the future - creating a conceptual map of the Serge that will be very helpful in feedback patching.

Apologies about the periodic focusing issues - I'm still working on it :)"

New Uses for Old Circuits 02: Sources Of Inversion

video upload by La Synthèse Humaine

New Uses for Old Circuits Series

"New Uses for Old Circuits is a series looking at linear and nonlinear processes in the modular system.

In this video we go through every module in the Serge synthesizer to discover which circuits create an inversion at the output. As a result, we create perhaps the most boring synthesizer video on YouTube, but we also lay some important groundwork for the future - creating a conceptual map of the Serge that will be very helpful in feedback patching.

Apologies about the periodic focusing issues - I'm still working on it :)"

EMS VCS3 Cornwall Modifications

video upload by Rhythmicons

"Some of you might want to get your VCS3 modded. This is part one in a series of videos showing the ones that I have added to mine. Shown is the Voltage Controlled Waveshaper and the Variable Oscillator Sync."

New Uses for Old Circuits 01: Slew Generators as Lowpass Gates

video upload by La Synthèse Humaine

New Uses for Old Circuits Series

"New Uses for Old Circuits is a series looking at linear and nonlinear processes in the modular system.

In this video we start from the basics and look at the two most famous modules of the Serge system: the Dual Universal Slope Generator (DUSG) and Smooth/Stepped Generator (SSG). These two flavors of slew generator allow us to not only create modulation sources but process audio signals, acting as low level lowpass filters."

Deckard's Dream X2

video upload by Love Hultén

"Beasty setup for a client incl two(!) Deckard’s Dream MK2, Mercury 7, Cosmos and an Osmose for MPE

Inspired by the Yamaha CS-50"

15 minutes with Smoothie Audio Smear, a 98-pole allpass filter

video upload by Signal Sounds and Tom Churchill

"Tom takes a look at Smear, the debut module from Smoothie Audio. It’s a dual stereo 98-pole allpass filter, and it’s capable of some pretty mind-bending spectral effects.

Buy here:
https://www.signalsounds.com/smoothie...

More from Smoothie Audio: https://smoothieaudio.com/products/smear"

via Signal Sounds:

"We say...
It's not often that we come across something genuinely new and innovative in Eurorack these days, but Smear is just that - a pair of stereo 98-pole all-pass filters that open up all sorts of strange sonic territory. Brilliant!

Manufacturer's description
Smear is Smoothie Audio’s first Eurorack module - a dual stereo 98-pole allpass filter unlike anything else in your rack.

At its core, Smear takes a deceptively simple concept - the allpass filter, usually buried deep inside reverb algorithms — and refines it into a playable, sculptural processor. A single allpass subtly shifts the phase of incoming audio while passing the entire signal unfiltered. Stack 98 poles in series, and the effect becomes striking: frequencies across the spectrum are delayed by different amounts, creating a rich spectral delay that can smear, morph, and transform sound.

Smear can be become different effects, according to how you set the parameters:

Transient Smearing & Spectral Delay that reshapes transients, can add punch
Resonator & Percussion Voice for metallic, physical-modeling tones when pushed into feedback territory
Morphing filter & Phasor for animated timbral movement
Interface & Controls

The panel is laid out symmetrically, with two identical sections (Left and Right). By default, stereo audio flows left → right → out, but a dedicated Split Mode allows each side to process audio independently.

Each section offers three core parameters — Frequency, Resonance, and Stages — each with dedicated CV inputs. Frequency and Resonance have attenuverters for precise modulation. A global Feedback control (with CV) unlocks resonant, flanger-like, and physical-modeling behaviors.

The Stage sliders reveal Smear’s hidden depth: with LEDs indicating crossfade modes between filter poles, you can dive into complex notch filtering, animated flams, and evolving timbral movement. Modulate them, and the module comes alive with unpredictable, dynamic filtering effects.

Built on the Daisy platform by Electrosmith
CV inputs -5V to 5V
48kHZ sampling rate"

RORSCHACH -TV drone jam

video upload by DecadeBridge

RORSCHACH is a video synth with "an audio output that converts the video signal into a distinctive drone voice." Full details below.

Video desciption:
"All audio from Rorschach running through a cheap delay pedal. The vertical movement on the screen is due to the faulty tracking on the TV. All patterns generated by Rorschach.
10% off pre-order.
Rorschach is available from the following places:-
https://decadebridge.etsy.com/uk/list...
https://lumaticvisual.com"



Rorschach by Lumatic Visual Devices is an analog-style video synthesizer designed for artists exploring video synthesis, live visuals, and audio-reactive image generation. It works equally well as an entry point into video synth hardware or as a creative expansion for experienced users.

Rorschach is well suited to live performance, with the ability to self-generate evolving patterns using its built-in randomisation features. Its functionality can be extended further by feeding control voltage, gate signals, or audio into the modulation inputs, making it easy to integrate into modular and experimental setups.

With a clear, functional, and immediate control layout, Rorschach is an excellent starting point for anyone taking their first steps into video synthesis, while still offering enough depth to remain engaging for more experienced users. Compact and portable, it also features an audio output that converts the video signal into a distinctive drone voice.

Rorschach generates its own black and white composite video patterns straight out of the box. Its functionality expands further when used alongside modular or Eurorack systems, or when audio signals or control voltage are fed into the CV and gate inputs. The focus is on experimentation, play, and hands-on control.

A dedicated random section allows the synthesizer to run freely, generating evolving patterns automatically and in real time. Leave it running during a performance, or introduce external signals such as a kick drum or sequencer to push the visuals into new territory.

Key features

Four main controls for horizontal position, vertical position, width, and height
– CV inputs for all four parameters
Form control selects from six pattern generator modes
– Can also be modulated via audio input or control voltage
Random control sets the amount of randomness applied to the four position parameters on each refresh
– Independent switches and gate inputs for each random parameter
– CV input for random amount
Clear screen modes:
– Clear / Random Clear / No Clear
– Gate input for clear screen
Pattern colour switching:
– White / Black / Invert
Horizontal and vertical mirroring switches
– Independent gate input for each axis
Composite video output via RCA connector
Audio output allowing the generated visuals to be used as a drone sound source
Power Rorschach is supplied with a 9V battery clip.
If you would like to run Rorschach off a wall adapter you will need a 9V CENTRE POSITIVE adapter.
Power requirements:- Minimum 70mA

CLICK FOR MORE »

Drone Scope by Tim Kaiser

video upload by Tim Kaiser

Circus @ 39 o'Clock (Roland DJ-70, ARP 2600m, Moog Slim Phatty, Novation Drumstation)

video upload by Mano Sol

"This is the third of a new series entitled 'Mono Soul: Samples, Synths and Oscilloscopes'...

Going back to how I produced music 30 years ago. Embracing the limitations and beauty of 60s, 70s, 80s, 90s and 00s technology. Repurposing and recycling technology and music.

Equipment used in this video:
Roland DJ-70 (sampling heavy lifting, VL Tone drums)
Moog Slim Phatty (fat synth bass)
Korg ARP 2600m (clanky bell sound)
Novation Drumstation (808 kicks and snares)
Macintosh SE running MOTU Performer 4.2
Korg SDD-2000 (echoes)
Roland RSP-550 (reverb)
Mackie 1402-VLZ Pro"

Making a sawtooth and sine from a triangle wave - converting waves the opposite way as usual .

video upload by organfairy

"I switch it on at 4:35 and run it with a sequencer at 5:25.

After having made the 'classical' sine wave generator • Analog sine wave generator [video below] and the 'sort of digital' sine wave generator • Synthesizing waveforms with a frequency di... [posted here] a couple of months ago, I thought I should do a sine wave the third way - if not for other reasons it could be to say that I have done a sine wave trilogy: Start with a triangle and convert it to a sine wave.
This is a method that was often used commercially. If a function generator has both triangle and sine it is often made this way, and the XR2206 component that is often found on cheap tone generator kits works this way internally. I am not sure about the EMS VCS3 but I have a suspecion that OSCILLATOR 1 is also based on this idea as it can make saw and sine at the same time.
I do start with making a sawtooth wave though. I have not seen this method used before, but I doubt that I am the first to have done it.

The music is sort of a mood composition where I focused more on the mood and the sound construction than the melody, which is rather unusual for me as I consider myself a melody focused music tinkerer. Whatever it is I made it on my Roland D-20."

Analog sine wave generator

video upload by organfairy

"I test run it at 4:15

After making that "somewhere in the swampy wasteland between analog and digital sine wave generator" last week, I decided to try and make a classical analog sine wave generator - just for the fun of it.
Sine wave generators are sort of an interesting thing: They are basically just an amplifier connected back to front through a filter, but the amplifier needs to be regulated in some way, otherwise the sinewave will get distorted to a point where it is often more a square wave.
This sine wave generator is not controllable from a keyboard like the other one I made, so it is more for modulation purposes or maybe if I one day take up the obscure art of musique concrete.

The musique ridicule that I play during the video is something I fumbled together playing my Korg Rhythm 55, Elka X-1000, and Roland D-20."

CHROMAGENE - Waveforms

video upload by Gene Synths

"Sound recorded directly from the back of the synth (No added effects / eq / reverb etc)."

See this post for additional details.

K-ACCUMULATOR: PULSARS

video upload by Fancyyyyy Synthesis

"Deposits for Batch 2 of K-ACCUMULATOR are now open. https://fancysynthesis.net"

See the announcement post here.

Update:

K-ACCUMULATOR: OSC

video upload by Fancyyyyy Synthesis

"K-ACCUMULATOR is a 21st Century Complex Oscillator. Find out more at http://fancysynthesis.net"

EMS Documentary Clips & Interviews

video uploads by Ektoplasmic Interzone

Update: video 8. w/ Liz Parker added.

Playlist:

1. Zinovieff featured on "Tomorrows World" (1968) - Clip from BBC Program
2. Zinovieff from BBC's "New Horizons" (1971)
3. Rise and Fall of EMS London - Zinovieff interview
4. EMS Studio London - Peter describes the challenges of the electronic studio
5. Peter and Robin at EMS Oxfordshire Studio
6. Malcolm Clarke demonstrates Synthi 100
7. VCS3 Waves and Harmonics
8. Liz Parker demonstrates Synthi 100 Radiophonic

And a massive playlist from Ektoplasmic Interzone featuring additional videos:

Electronic Music Studios (EMS) London Ltd Synthi


You can use the player controls to skip around. Click the drop down on the trop right of the player to scroll through titles.

Synthesizing waveforms with a frequency divider - a sequel

video upload by organfairy

"I show how it sounds at 4:17 and play it with a keyboard at 5:50

Winter is getting closer so this is the time of year when I start building things. The first of my projects is a revisit to an old idea of synthesizing waveforms with a frequency divider. This time the waveform in question is a sine wave and some other waveforms derived from it.
The old idea is here: • Synthesizing waveforms with a frequency di... [below]
The project is quite a bit more complicated than the previous 'digital' waveform synthesizer as the sine wave is very..... well....wavy, as there are no straight lines like there is in the triangle and sawtooth waves. Therefore I had to take a different approach using a couple of 74LS138 3-8 decoders and an awfull lot of resistors.

The music is my attempt at playing something relaxing on my Wersi Prisma DX-5 organ."

Synthesizing waveforms with a frequency divider

video upload 8 years ago by organfairy

"The demo starts at 4:15.

The normal approach to generating waveforms is to start with a sawtooth wave and then fold it into a triangle wave and schmitt trigger it into a square wave. But it is also possible to synthesize the waveforms by means of a frequency divider and some logic gates. Off course the generated waveforms will be somewhat 'edgy' but that can probably be filtered out and some people might even find it usefull.

The music is something I made back in 2005 on the homemade synthesizers I had then. It's not the best piece I have made but I am still willing to take responsability for it :-)"