Tag: Synthesizers

This post was inspired by a close reading of Ray Wilson, Make: Analog Synthesizers (2013). A close reading is not the same as a great appreciation. The initial problem with the book is that it is a vehicle to promote Ray’s day job, the production and sale of Music From Outer Space (MFOS) analogue synthesizer kits. Another problem is that the author/ editors confuse slang and humour with an ability to make a text easy to understand. They do not. For people who have English as a second language, these two components add confusion. The book is described as a hands-on dive into the tools, techniques, and information needed for making an analogue synthesizer. Hopefully, this information will be unnecessary for anyone with experience in building synthesizers, so it is only suitable for people lacking this experience.

Some of the negative vibes about Wilson’s project come from his reuse of the company/ product name. Leonard Nimoy Presents Mr. Spock’s Music from Outer Space, the debut album of Leonard Nimoy (1931 – 2015), was recorded in character as Mr. Spock from Star Trek, and released 1967-06.

Much of the book assumes that the interested reader is building an analogue synthesizer from a MFOS Noise Toaster kit. No other kit or project will do. It is that specific. Earlier parts of the book are useful in explaining the differences between analogue and digital synthesizers (and then forgetting about digital synthesizers), the building blocks incorporated into an analogue synthesizer, including voltage-controlled oscillators (VCOs), filters (VCFs) and amplifiers (VCAs) as well as low frequency oscillators (LFOs). There are suggestions about making a workshop suitable for synthesizer production. Some of these suggestions are useful, especially those about modifying equipment to make it more suited in a low cost workspace. Some of the foundation circuits for amplification, biasing, and signal mixing are also useful, as is much of the information about setting up and using a budget electronic music studio.

MFOS’s description of the Noise Toaster even lists the following features (orthography in the original): WILL attract alien visitations – CAUTION ADVISED; WILL DEFINITELY cut into TV viewing time – CAUTION ADVISED; Stimulates plant growth and calms goldfish. While the kit is described as lo-fi, it has a price tag that is excessive for that category: US$ 209 = € 187 = NOK 1793, at the time of writing. Periodic checks indicate that this kit is permanently out of stock.

In the weblog post Tech Ed some helpful, electronic textbooks are discussed. One book that was not mentioned was Forrest M. Mims III, Getting started in electronics. It began life in 1983, but the edition I have, from Master Publishing, is dated 2003. This is a good introductory book, if somewhat dated, that many people will prefer to, say, Harry Kybett and Earl Boysen, All New Electronics Self-Teaching Guide, 3rd edition (2008), or later books based on this.

My advice to a prospective 16-year old synthesizer builder is to begin by reading, and working with the Mims textbook, then go on to Kybett and Boysen. With sufficient theoretical knowledge in place, a Eurorack synth component can be made.

Rather than MFOS, my preference for a starter kit involves open-source Erica EDU DIY Eurorack projects. Erica Synths was founded in Latvia in 2014 by Girts Ozolinš. Originally, these Synths used Soviet parts. That time has passed, mostly. Erica Synths discontinues its legacy DIY eurorack projects, but decided to make them open-source. They made slight changes to module design to eliminate custom/ rare components. However, this was an imperfect process, as some modules still require relatively uncommon ICs. It is claimed that these can be sourced from Erica Synths. Then they created a folder for each project, with Gerber files for printed circuit boards (PCB) and front panels, and complete information/ files to build a module: schematics, including bills of materials (BOM), component placement with values and designators, and assembly manuals. Note: some manuals are designed for older module versions. Open source allows them to be available for personal, educational and/or commercial purposes.

Gerber is an open ASCII vector format, and de facto standard, for PCB designs, including copper layers, solder masks, drilled holes and printed data.

An almost unpronounceable brand name, mki x es.edu, is a joint effort between Erica Synths and YouTube presenter Moritz Klein. It claims that its goal is to teach people with little-to-no prior experience how to design analog synthesizer circuits from scratch. Design is the key word in that statement that they want to emphasize. The components in the kit box are not simply meant to be soldered together and then disappear inside a rack. Instead, they claim that they want to take the constructor through the circuit design process step by step, explaining every decision and how it impacts the finished module. A related, but cheaper, approach is to download the manuals, study them, and then decide if one wants to purchase kits.

Starting at 2021-12-28, they are in the process of offering new kits at the rate of one every four to six weeks. A total of 9 kits are planned. When completed this results in a fully-featured modular monosynth: 1) a sequencer, 2) a VCO at €60, 3) a wavefolder (used to shape soundwaves), 4) a noise/ sample and hold (S&H) module, 5) a mixer, 6) a VCF, 7) an envelope generator (EG) at €55, 8) a dual VCA unit at €55, and 9) an output stereo mixer with a headphone amplifier. In addition, a eurorack case with a DIY power supply unit (PSU) is available at €110. Even if a complete kit costs about €700, it should offer greater value for money than a MFOS Noise Toaster!

Kits have a 40+ page user manual that can be downloaded separately, and in advance of any purchase. These provide information about the electronics behind each circuit, also the fundamental principles of sound synthesis. We hope that the project will inspire future engineers and will contribute to the ever-growing diversity of electronic music technology.

The advantage of a Eurorack component, is that it allows one to start with a very simple project that is only part of a functional synth. One can build up construction experience gradually. One can also mix and match components from several manufacturers, or make them.

If one is determined to follow the Wilson trajectory, arrange a conditional sale of a finished MFOS kit-build of a Noise Toaster at cost, at the same time one is reading the Wilson book, and building the kit. The reason for this approach is that once the Noise Toaster is built and sold, the builder is free to decide if s/he wants to build another synthesizer and, if so, the type – without being constrained by the ownership of an existing kit.

My suspicion is that kit builder are seldom content with the simple, but want to construct more complex design. However, a word of caution may be needed. I remember hearing from someone that only the third (or later) iteration of a project actually results in a usable product. The first iteration is overly simple, because one is in the process of developing one’s skills. The second one is overly complex, because with the success of the first project, the constructor is open to anything and everything. The third iteration, involves moderation.

This appears on what would have been the 90th birthday of Peter Zinovieff, (1933-01-26 – 2021-06-23) composer, hesitant engineer and reluctant synthesist.

There are some elements to Zinovieff’s life, that only happen because of his Russian aristocractic background. In 1960, Zinovieff married Victoria Heber-Percy (1943 – ). Her tiara was auctioned, to finance Zinovieff’s first computer. This was used to control an array of oscillators and amplifiers he had bought from an army surplus store. He claims that this was the first computer in the world in a private house. I am uncertain what benefits Heber-Percy got out of the sale of her tiara, but the marriage did not last.

Zinovieff closely followed some developments in computing related to sound generation. In particular this was happening at Bell Labs in New Jersey, where its owners had a vested interest in telephone research. There in 1957, Max Mathews (1926 – 2011) had written MUSIC, the first widely used program for sound generation. This had been further developed in the 1960s with new versions. In 1964, Jean-Claude Risset (1938 – 2016), had used MUSIC IV software to digitally recreate the sounds of brass instruments. He made digital recordings of trumpets and studied their timbral composition using pitch-synchronous spectrum analysis tools.

In 1963, David Alan Luce’s (1936 – 2017) doctoral research at the Massachusetts Institute of Technology implemented a pitch-synchronous approach to analysis/resynthesis of instrumental tones. Luce  joined Moog Music in 1972, where he developed a polyphonic synthesizer, the Polymoog. Later, he became head of engineering, then president of Moog in 1981. He became a co-owner in 1984. Moog Music closed in 1987.

In 1966–67, Zinovieff, Delia Derbyshire (1937 – 2001) and Brian Hodgson (1938 – ) ran Unit Delta Plus, creating electronic music. Its studio was built by Zinovieff in a shed at his house in Putney, Greater London. Unit Delta Plus had a short life, and was disbanded in 1967.

Zinovieff worked with a medical technician with electrical engineering skills, David Cockerell (? – ) and software engineer Peter Grogono (1944 – 2021) to develop an analogue–digital (hybrid) performance controller. Grogono was tasked with developing a new musical composition and sequencing language, MUSYS, that was to be easy to use (composer friendly) and efficient, and working within the limitations of two Digital Equipment PDP8/S and PDP8/L older and newer computers, respectively, named Sofka and Leo, after Zinovieff’s two first children. The system saved output data files to disk. A musical keyboard was added for input, as an afterthought.

In the mid-1960s electronic components were expensive, and the equipment being made exceeded Zinovieff’s means. Thus, it was decided to sell some machines to finance further development costs. Zinovieff, Cockerell and composer Tristram Cary (1925 – 2008) founded Electronic Music Studios (EMS). It is likely that the name was selected for this enterprise prioritizing a studio making music, while ignoring a product manufacturer making synths. EMS created a commercial, miniaturised version of its studio as a modular, affordable synthesizer for the education market. A prototype called the Voltage Controlled Studio 1 (VCS1) was designed by David Cockerell, consisting of a two oscillator instrument built into a wooden rack unit, and built for the Australian composer Don Banks (1923 – 1990) for £50, after a lengthy pub conversation.

Some of this equipment was subsequently marketed as a synthesizer system using the EMS label. It was considerably more portable than the existing Moog system. Possibly because Robert Moog recognized the limitations of his synthesizers, he offered to sell out to EMS for one million dollars. Zinovieff turned down this offer.

The EMS Synthi 100 was a large analogue/digital hybrid synthesizer series, of which 30 were produced. The first unit was orriginally a custom order from Radio Belgrade for its Radio Belgrade Electronic Studio. This order was the result of contact between composer/ saxophonist Paul Pignon (1939 – ), then living in Belgrade, and Zinovieff. The synthesiser was designed by David Cockerell who documented it in detail in 1971. The cost at that time was £ 6 500.

While EMS lasted until 1979, its key personnel soon began leaving the company. Cockerell left in 1972 to join Electro-Harmonix to design effect pedals. Cary left in 1973 to become Professor of Electronic Music at the Royal College of Music and later Professor of Music at the University of Adelade. Grogono left in 1973 but continued working on the MUSYS programming language and further developed it into the Mouse language. He became a computer science professor at Concordia University in Montreal, Canada.

The main challenge for Zinovieff was his aristocratic origins, that prevented him from doing technical work. In 2019 he commented on EMS as a business: “It’s always been a problem with me because I don’t like synthesizers. So this side of EMS was never interesting to me, it was always the studio. The basic purpose of EMS was to finance the studio, but unfortunately that’s not what happened. EMS got bigger and bigger and we made more and more products and it took up more time. And instead of making money, it started to lose it. In the end, when EMS went bankrupt, it pulled the studio down.”

Zinovieff then closed the Putney studio, which was sold to the National Theatre. The equipment was put into storage, and later destroyed in a flood.

He then moved to the remote Scottish island of Raasay between 1975 and 1983. His cottage had no mains electricity supply, so synths were powered by wind generation that charged batteries.

He then move to Cambridge where, in the 1980s, he received two commissions from Clive Sinclair (1940 – 2021) including a piano-sampling project and consultations on sound support for the Sinclair QL personal computer, launched in 1984.

Zinovieff as Composer

In 1968, Zinovieff staged the world premiere of Partita for Unattended Computer, notable for being the first ever unaccompanied performance of live computer music, with no human performer involved, with the piece read from paper tape.

Later in 1968, as part of Cybernetic Serendipity, the first UK international exhibition devoted to the relationship between the arts and new technology, Zinovieff et al created a computer system, that could analyse a tune whistled by a visitor to the show and improvise upon it.

Zinovieff collaborated with Harrison Birtwistle (1934 – 2022) on Chronometer (1971–2) with recordings of Big Ben ticking, and Wells Cathedral clock chiming. Zinovieff claimed that in this project he had invented the technique of musical sampling.

The soundtrack for Sidney Lumet’s (1924 – 2011) film The Offence (1972) was composed by Birtwistle with electronic realization by Zinovieff.

Zinovieff also wrote the words for Birtwistle’s Nenia: The Death of Orpheus (1970) for soprano, 3 bass clarinets, crotales and piano. Here the electronic realization was by Barry Anderson (1935 – 1987). Zinovieff wrote the libretto for Birtwistle’s opera The Mask of Orpheus (1973-84).

He also worked with Hans Werner Henze (1926 – 2012) producing a tape in Tristan’s Folly in Tristan (1975).

Through an association with Francesca Thyssen-Bornemisza (1964 – ), Zinovieff was able to create an audio work for a large-scale installation, The Morning Line by Matthew Ritchie (1964 – ), Bridges from Somewhere and Another to Somewhere Else (2011). Good Morning Ludwig (2012) followed.

Following these projects, Zinovieff’s compositions typically combined sounds from live instrumentation and field recordings and multi-channel performances.

He collaborated with Kazakhstani violinist Aisha Orazbayeva (1985 – ), composing two concertos for violin and electronics: OUR (2010) and Our Too (2014).

From 2011 he collaborated with Scottish poet, historian and broadcaster Katrina Porteous (1960 – ) to combine her poetry with soundscapes created by Zinovieff using sound sources related to physics and astronomy. This resulted in Horse (2011), then with the Planetarium at the Centre for Life, Newcastle upon Tyne, Edge (2013), Field (2015) and Sun (2016). Live visuals for these last works were created by planetarium supervisor Christopher Hudson.

A retrospective compilation of Zinovieff’s work in the EMS era was compiled by English musician Pete Kember/ Sonic Boom (1965 – ) and released in 2015.

Zinovieff collaborated with cellist Lucy Railton (? – ) on RFG (2016). An album version was released as RFG Inventions for Cello and Computer (2020).

Between the years 2013–2017, Zinovieff composed South Pacific Migration Party, based on from hydrophone recordings of blue whales recorded by British oceanographer Susannah Buchan off the coast of Chile. In was released on the record label The Association for Depth Sound Recordings in 2021.

Zinovieff’s final work was, Under The Ice (2021), a 30-minute piece based on recordings of Antarctic glaciers.

When this weblog post was being planned, it was hard to decide if the focus should be on Swiss engineer Uli Behringer (1961 – ), or on the audio equipment company he founded. Currently the company is privately owned by his holding company, based in the Philippines, but with production facilities in Zhongshan, China. It will be both.

Did Uli Behringer have any options in life apart from becoming the founder of an audio electronics company? Much of his family were professional musicians. He started to learn piano at age four. At age five he assisted his father to built an organ with over 1000 pipes and integrated them into the family house. At age sixteen, he built his first synthesizer, the UB1.

Behringer, the company, was started in Germany in 1989. By 1990, it had moved to China, with products being made by subcontractors to reduce production costs. In 1997, Behringer himself moved to Hong Kong, in an effort to improve product quality. In 2002, the company completed a 110 000 m² manufacturing complex in Zhongshan. Here, ten separate production locations form a vertically integrated, eight-building facility where 2.5 million products, including assorted electronic units, speakers, guitars and digital pianos are produced annually.

Synthesizers have been produced by Behringer since 2016. In Norway, there are 18 distinct Behringer desktop synthesizer models available, some with keyboards, some without. These are analogue instruments, meaning that they will produce sound through a headphone or speaker, without the use of additional equipment. Many of these are clones of earlier synthesizer products, whose intellectual properties (such as patents) have expired. There are also 63 different Eurorack components available.

The first synths produced were a twelve voice Deepmind 12, a six voice Deepmind 6 that effectively imitate a Roland Juno-106. The Deepmind 12D is a simpler desktop version. In 2022, these cost about NOK 7 800, 5 500 and 6 850, respectively. While these models offer relatively good value for money, they are expensive as a first synthesizer, where a user will want to experiment in order to find something that suits her/his soul. Others disagree.

The next synth, the Neutron, provides a 56 point mini-jack patch bay. This is ideal for enthusiasts addicted to patch cables. For others, the appeal of the Neutron is its low price, currently NOK 3 355, and the fact that it is equipped with a clone of the synth on a chip technology used in the Curtis CEM3396 integrated circuit (IC). This IC was responsible for the main voltage controlled oscillator (VCO) used in many synths from the 1970s and 1980s including: the Oberheim OB-Xa, OB-Sx & OB-8; the Voyetra 8; the Roland SH-101, MC-202, Jupiter-6, and early model MKS-80; the Sequential Circuits Prophet-5 Rev 3, Prophet-10, Prophet-600, Pro-One, and Prophet T8; Moog Memorymoog; Banana Polysynth; Crumar Spirit; Digisound 80 VCO modules; the Synton Syrinx; Steiner Parker EVI; and, Doepfer A-111-1 High End VCO. This allows the Neutron to recreate the sound of many of these former synths. Here is a video that shows the operational characteristics of the Behringer Neutron.

Electronic Dream Plant (EDP), an Oxfordshire, England based synth manufacturer, was started in 1977 by Adrian Wagner, a synthesist, and Chris Huggett (1949 – 2020), an electronics engineer. Huggett designed the Wasp, and EDP started selling it in 1978. In 2019, Behringer made a clone of the original Wasp, the Wasp Deluxe. The Wasp will appeal to those wanting to avoid patch cables. Once again, it includes a clone of the Curtis CEM3396 IC. It is also ideal as a starter synth. Here is a video that shows the operational characteristics of the Behringer Wasp Deluxe. When it first came out, the its price was NOK 3 400. Now it is a little over NOK 2 300.

In most situations an open-source software/ app synth on a computer is a suitable substitute for an analogue synth, saving space and money. The challenge is the lack of a musical keyboard for input. On 2022-04-01, I took home a Behringer MS-1 RD in red, as my first analogue synth, their cheapest keyboard synth with 32 semi-weighted, full size keys. It cost NOK 3 600. Another characteristic of this synth, was that it was one of only two MS-1 synths available anywhere in Norway, the only other one was a MS-1 BU in blue, not my favourite colour. The purported reason for this was, once again, a chip shortage.

The other synth under consideration was a Behringer Odyssey, previously mentioned. It increases the number of keys to 37, is duophonic, but occupies considerably more desk real estate. It also costs almost NOK 5 000. While marginally more capable than a MS-1, the Odyssey would not be a stopping point, should my skills develop sufficiently.

At some point in the future, I might be tempted to supplement/ replace the MS-1 with a polyphonic synth with more keys and aftertouch = the ability of a keyboard to change tone (or other sound qualities) in response to velocity, pressure or other playing variations. The Behringer Deepmind 12, previously mentioned, offers more synth at a cheaper price than most other polyphonic analogue synths available. However, the design is dated and it is not on any future shopping list. The main reason is a three letter word, fan = a device that moves air, usually for cooling purposes. It also produces unwanted noise.

My current conclusion is that I have bought my first (and last) Behringer synth. However, they offer good value for money for any individual wanting to buy a first synth.

Short Version

From about 1963 to 1980, a Mellotron was an electro-mechanical instrument that used recorded samples of orchestral instruments stored on special tape-recorder tapes to produce a variety of sounds, using a divided keyboard, with the right half playing the tune, while the left half offered more rhythmic support.

Most musicians in the 21st century, will have no need for a Mellotron, Its major use is to recreate – with precision – some of the orchestral sounds, used by groups from the mid 1960s and onward into the 1980s. One such group is the Moody Blues, where the Mellotron can be clearly heard throughout Love and Beauty (1967).

The Mellotron is available in obsolete versions, such as the one depicted in the photo above, in smaller, lighter more modern variants or as cards to be inserted into computers (both handmade in Sweden today), or as fully digital software apps, typically offering 8 or 18 voices.

For most people, modern keyboards will offer a range of orchestral voices that is gudenuf for home consumption, or even a gig. Enthusiastic admiration of a Mellotron is a clear indication of a person living in the past.

Long Version

To understand the development of the Mellotron, it helps to begin with the early evolution of drum machines.

The first drum machine was the Rhythmicon, designed by Leon Theremin (1896 – 1993) in 1932. Theoretically, it was versatile, but far too difficult to play, even for an experienced professional musician. It had been commissioned by the eccentric/ controversial composer/ pianist/ performer Henry Cowell (1897 – 1965), who quickly and quietly ignored it.

The next product was the Chamberlin Rhythmate. At some point towards the end of the 1940s Harry Chamberlin (? – 1967) started development. It took years. By 1957, a Model 100 Rhythmate, became the world’s first sampler, relying on tapes to reproduce recorded loops of drum patterns.

Chamberlin’s business model was disrupted by the 1959 Wurlitzer Sideman, that used a rotating disk to produce percussion sounds. This was a successful product, effectively eliminating the need for the Rythmate. Wurlitzer ceased production of the Sideman in 1969.

Thus, subsequent models of the Rythmate included keyboards, and extended the range of sounds produced, using a proprietary 3 track, 3/8” tape format. These enabled Harry Chamberlin to be the exclusive seller of the tapes, if only people would buy the machines!

New models regularly emerged. By the early 1960s, Chamberlin developed the Model 600 Music Master, that included two 35 note keyboards (G to F). The right-hand keyboard was used for the instrument sounds (flute, violins, etc ), while the left-hand one was used for the rhythmn accompaniments (Bossa Nova, Cha Cha Cha, Tango, etc).

In the early 1950’s, Harry Chamberlin hired former window washer Bill Fransen as a salesman. Unfortunately, while the instrument’s concept was appealing, its execution produced an unreliable machine, that was difficult to sell.

Fransen took two Chamberlins 600 Music Masters to England, looking for a manufacturer that would be able to supply 70 replay heads. In Birmingham, he engaged Bradmatic, who built the requested replay heads. After Fransen showed them the two Music Masters, they agreed to make a more reliable instrument, and to mass produce it. In 1963, this improved instrument became the Mellotron Mark 1. The designer of this instrument was Leslie Bradley (? – 1997). This electro-mechanical instrument was now much more than a drum machine, but far less than a synthesizer. It was approaching what people today refer to as a keyboard, but excessively heavy and large.

Using British funding, band leader Eric Robinson (1908 – 1974) set up Mellotronics Ltd in London, and recorded various instruments at IBC studios (International Broadcasting Company), which he owned with George Clouston, who worked for the BBC.

In 1965, the Graham Bond (1937 – 1974) Organisation was the first band/ musical group to use a Mellotron to record a single, Lease on Love, and an album, There’s a Bond Between Us.

A Mellotron was also used on Manfred Mann’s (1940 – ) single, Semi-Detached, Suburban Mr. James (1966).

The Beatles first discovered the Mellotron during a visit to IBC studios in London on 1965-08-09. John Lennon ordered a Mark II, which was delivered to him 1965-08-16. The most famous Beatles’ song using a Mellotron is Strawberry Fields for Ever (1967), where it substitutes for a flute.

In 1964, a Mark II model was produced. Mike Pinder (1941 – ) worked on quality control at Bradmatic for 18 months. Shortly after, he acquired a Mark II which became the musical foundation of The Moody Blues, a group he had just founded. Using a Mellotron, Love and Beauty (1967) became the group’s first hit. Because of his experience acquired at Bradmatic Ltd, Pinder was able to make technical improvements to his instrument. These included the replacement of accompaniment sounds on the left keyboard with additional instrument sounds, as typically provided only on the right keyboard, allowing it to have a total of 36 instruments.

The possibilities offered by the Mellotron attracted many musical groups: The Rolling Stones, The Kinks, Pink Floyd and King Crimson. It was the first fully polyphonic instrument which allowed a faithful reproduction of other instruments including strings, brass, flute and vibraphone. There were other keyboard instruments available: electric organs (Hammond, Vox, Farfisa), acoustic and electric pianos (Rhodes, Wurlitzer) and monophonic synthesizers (Moog, ARP). However, these either could not offer the variety of sounds, or their learning curve was so steep, that it was not worth the effort.

In 1965, Harry Chamberlin travelled to Britain to visit Bradmatic. A financial arrangement was made with the Bradley brothers allowing them to continue manufacturing the Mellotron and to use the famous sound of strings (3 Violins), the only sound common to Mellotron and Chamberlin.

Bradmatic changed its name several times to successively become Bradmatic Productions, Mellotronics Manufacturing, Aldridge Electronics and finally Streetly Electronics. With the growing success of the Mellotron, Streetly marketed the Mellotron directly, then delegated it to Dallas Arbiter.

Because of the success of the Mellotron, the BBC asked Streetly Electronics to develop a Sound Effects Console (FX Console) Mark II version, whose technical specifications were adapted to the needs of the BBC. This involved the recording/ acquisition of 1260 sound effects to provide sound for radio and television broadcasts.

In 1968, a M300 version emerged, offering a single 52-note keyboard and eliminating amplification. Despite its scaled-down size, it was still a large and difficult instrument to transport. Some bad design decisions tarnished the model’s reputation, and only 52 copies were produced.

By 1970, a M400 became the first Mellotron that was (relatively) easy to transport. Its mechanics were simplified compared to previous models, allowing the use of interchangeable tape frames. Each tape had 3 tracks, with each frame holding a bank of 3 sounds. It was possible to order additional frames with other sounds. Many new recordings were made for the M400. It was Streetly Electronics’ biggest commercial success. Here is a video explaining how the M400 works.

From the end of the 60s, the Mellotron was used increasingly in progressive rock, by groups that include Genesis, Yes and King Crimson. It offered a polyphony, that was sometimes described as melancholic or bewitching.

In 1975, the Mark V arrived. It was, essentially, two M400s in a single box, but with the addition of a reverberation unit.

In the United States, the Mellotron was distributed from 1972 to 1976, by Dallas Arbiter, later, Dallas Music Industries (DMI). DMI’s bankruptcy resulted in Mellotronics transferred distribution rights to Sound Sales, which acquired the registered name Mellotron. This DMI bankruptcy also resulted in the closure of Mellotronics in Britain. Instruments made by Streetly Electronics, lost their right to use the Mellotron name, but used Novatron as a replacement name.

In 1981, the 4 Track is the first American Mellotron, manufactured by Sound Sales. In essence it is an M400, but is able to play 4 tracks on 1/4″ format tapes with an equalization for each track, volume and pan. This recording quality of the tapes was so poor that only five copies were made.

At the beginning of the 1980s, other, better samplers arrived on the market: notably, the Fairlight CMI, the Emulator I and the Mirage Ensoniq. Despite their technical innovations, these machines were expensive, and provide poor sound fidelity, that lasted only a few seconds. By the mid 1980s technological advances resulted in more efficient and less expensive machines, typically made in Japan by Akai and Roland.

At this point, the Mellotron is obsolete. Streetly Electronics ceases operations in 1986. Some years later, John Bradley, son of Mellotron designer, Leslie Bradley, and Martin Smith, founded Mellotron Archives UK. This becomes Streetly Electronics. It remodels, maintains and sells parts and bands/ tapes for all Mellotron models.

In 1989, David Kean purchased the bankrupt estate of Mellotron in the US and bought all remains of the associated UK companies. He resurrected the Mellotron brand. He was then joined by Markus Resch, an engineer. In 1990 they began making tapes, spare parts, and start building what would become the Mark VI Mellotron in 1999, described by its manufactures as: a newly manufactured, electronically and mechanically improved tape-replay instrument. Unfortunately, it also includes a tube pre-amp, which is a regressive measure.

About 1999, David Kean began divested himself of his interest in the Mellotron company, and moved his new project, the Audities Foundation to Calgary, Alberta, Canada.

Since 2001, the Mellotron company has been owned and operated by Markus Resch, in Sweden. It now produces both analog and digital instruments as well as apps under the brand Mellotron. In 2005, the Mellotron Mark VII was launched. Both the Mark VI and the Mark VII machines are still in production, although the Stockholm shop with its listening centre has closed.

Inspired by the Ondes Martenot (1928) and the Electro-Theremin (1950), the Therevox ET-4 is controlled by moving a finger along a reference keyboard shaped to provide tactile feedback. Dual pressure sensitive intensity keys control the amplitude of the ET-4‘s two independent analogue oscillators. Combined with a low-pass filter, white noise generator and internal spring reverb the ET-4 is an expressive and versatile performance instrument.

Therevox began building custom instruments in 2004. Their first product was the ET-1, a modern version of an Electro-Theremin. The Electro-Theremin was designed by Paul Tanner (1917 – 2013). It was constructed by Bob Whitsell (1930 – 2009). Tanner then played the instrument. It can be heard on the theme song of My Favorite Martian (1963 – 1966) and The Beach Boys’ Good Vibrations and I just wasn’t made for these times (both, 1966) .

In 2008 a limited edition of twelve updated ET-3‘s went to musicians and studios in North America and Europe.

In 2012 they released another continuous pitch analog instrument inspired by the Ondes Martenot and early analog synthesizers. This ET-4 is the current model.

• The ET-4.1 is the standard model,
• The ET-4.2 adds an effects loop and some other features
• The ET-4.3 adds MIDI over USB output.

Every ET-4 is individually hand crafted in Tecumseh, Ontario, Canada, “using high quality components and select North American Walnut. With less than 20 made a year the Therevox ET4 is an exclusive instrument. All soldering, calibrating and assembling is also done in the Tecumseh workshop.”

The ET-4.1 is the standard model, the ET-4.2 adds an effects loop and other features and the ET-4.3 also adds MIDI over USB output.

The instruments are designed to be versatile and durable. It has been featured on several albums and film soundtracks. Composer Adam Taylor (1942 – ) used an ET-4.1 to compose the theme and incidental music for The Handmaid’s Tale.

Connections:

The Handmaid’s Tale (1985), written by Margret Atwood (1939 – ), is a futuristic dystopian novel set in a near-future patriarchal, totalitarian, theonomic Republic of Gilead, located somewhere in New England, where the federal United States government has been replaced. Some of the themes taken up in the novel are the subjugated of women and their loss of agency and individuality, the suppression of their reproductive rights, more specifically the subjection of fertile women to child-bearing slavery. More positively, the novel explores the various means by which women resist, attempting to gain individuality and independence.

The television series, based on the novel, consists of six series, developed from 2017. The last season will be shown in 2023. These were made in Toronto, and other locations in Ontario.

Atwood’s partner, from 1973 until his death, was Graham Gibson (1935 – 2019). Together, they had one daughter. Gibson was particularly noted for his interest in birds, having written The Bedside Book of Birds (2005) and The Bedside Book of Beasts (2009). He was a founder and chair of the Pelee Island Bird Observatory.

Tecumseh and Pelee Island are both locations in Essex County, Ontario. Windsor, where I originated, is also in Essex County, about 17 km from Tecumseh.

For people living – possibly even born – in the 21st century, Eurorack is a major approach to acquiring an affordable synthesizer. It is not a specific instrument, but a modular synthesizer format originally specified in 1996 by Doepfer Musikelektronik. It has since grown in popularity, and as of 2018 has become the dominant hardware modular synthesizer format, with over 5000 modules available from more than 270 different manufacturers.

Stated another way: If you, as a synthesizer playing person, want to base your synthesizer on modular components, there is no point in acquiring anything that isn’t Eurorack compatible; If you are a synthesizer module manufacturer, there is no point in offering modules that aren’t Eurorack compatible. Eurorack is the unavoidable standard, the intersection between module consumers and producers. Here, in this weblog post, the Eurorack specifications will be examined in some detail.

The mechanical specification for the Eurorack are derived from Eurocard, but with additional power supply and bus board specifications. The power supply is currently specified as A-100 PSU3, updated in 2015. Many cases adhere to the A-100 PSU2 specification, this allow modules to fit into existing (read: used) rack cases.

The Doepfer bus board allows for a maximum of 14 modules to be plugged in. A standard Doepfer case, either rackmount or portable, consists of two rows of 84hp, 6U high, that contain one PSU and two bus boards.

Doepfer-style bus boards are circuit boards. An alternative to these is a flying bus board. These have similar connections but use a flexible ribbon. This is often preferred, as mounting circuit boards can sometimes prove difficult.

The modules themselves have to meet Eurocard specifications for printed circuit board (PCB) cards that can be plugged together into a standard chassis which, in turn, can be mounted in a 19-inch rack. The chassis consists of slotted card guides top and bottom, into which cards are slid so they stand on end. The spine of each card has one or more connectors which plug into mating connectors on a backplane at the rear of the chassis.

Module height was three rack units (3U) and the width was measured in the Eurocard-specific Horizontal Pitch (hp) standard, where 1hp equals 0.2 inches, or 5.08 mm. The modules were largely low-cost, compact, and had some components on their boards that were socketed instead of soldered down, so the user could, for example, upgrade to a better op-amp IC.

Nathan Thompson, writing as nonlinearcircuits, has posted 33 laser-cut Eurorack cases, plus rails and some other components on Thingverse. Most of the cases date from 2015 and 2016.

Modules connect to a bus board using a 10-to-16 or 16-to-16 pin cable, depending on module design. These 16 pins are arranged in pairs and carry the following signals, from top to bottom: Gate, CV, +5V, +12V, GND, and -12V. The bottom 10 pins do most of the work, providing + and -12V to power the modules. The top two pins are for Doepfer’s optional internal CV and Gate routing. The +5V rail is used on some modules that require more power.

Plugging modules in, is not always as simple as it seems. Experienced Eurorack users will rigorously check connections before powering up, no matter how long they’ve been working with the system. Typically, the red stripe on the ribbon cable connecting the modules to the bus board must line up with -12V. This should be labeled on the module, and is always labeled on the bus board. Plugging a module incorrectly may have expensive ramifications.

A-100 PSU2 provides 1200 mA = milliamps of current to both the +12V and -12V rails. This has to be compared with the power drawn by a module. This has to be less than what the PSU specifies. The A-100 PSU3 also provides +5 V of power.

With the classic Doepfer case, a user would need to consume less than 1 200 mA on both rails. Modules should be almost evenly split between the two bus boards. If a module requires +5V, most manufacturers, including Doepfer as of 2015, either a PSU3 has to be used, or an adapter, which takes current from the +12V rail. The amperage required on the +5V rail will be subtracted from that available current on the +12V rail. The power specifications in Eurorack are not technically standardized, but most follow the Doepfer standard.

Perhaps the most important consideration, but one that may be difficult to answer for someone new to synthesizers and/ or Eurorack, is deciding on the type of rig to make.

Some people refer to a classic analogue synth, a rig capable of generating its own waveforms with wave-shaping tools to add character including textures and timbres to the generated signal. Another approach is to build an effects rack that processes sound generating elsewhere. These can be monophonic, stereo or polyphonic. Below this, one can build a drum machine that is focused on rhythm, rather than more tonal qualities.

One major advantage of Eurorack is its modular nature, allowing an opportunity to add and delete modules. To construct a self-contained instrument one needs: an oscillator, a filter, a voltage controlled amplifier (VCA), two envelope generators, one for the filter and another for the VCA, an effects unit, a mixer and/ or an output module.

Beginners are often encouraged to choose an analogue oscillator. These are easy to find and use, while still offering opportunities for creative expression.

Voltage-controlled oscillator (VCO) generate waveforms—sine, triangle, sawtooth, ramp or square waves— that are slightly unstable, with fluctuations in pitch and timbre as the voltage changes over time, this gives the oscillator a unique character.

Filters impact sounds the most. For better or worse, many modern synths use filters with characteristics that emulate those found on specific vintage synthesizers.

Robert Moog’s (1934 – 2005) lasting impact on synthesizers, starts with his dictate of 1 V per octave. Increasing the voltage going into a VCO by 1 volt raises its pitch by one octave. To understand this, consider a piano and how it is tuned. Convention dictates that middle C is referred to as C4. Tuning is based on A4, two white keys below, or to the left of, middle C. A4 has a standard frequency of 440 Hz. For convenience, it will be assumed that this is produced by a VCO signal of 4V. Thus, the relationship between note, voltage and frequency can be expressed by: A0 = 0V = 27,5 Hz; A1 = 1V = 55 Hz; A2 = 2V = 110 Hz; A3 = 3V = 220 Hz; A4 = 4V = 440 Hz; A5 = 5V = 880 Hz; A6 = 6V = 1 760 Hz; A7 = 7V = 3 520 Hz; A8 = 8V = 7 040 Hz. Note: Not all VCOs are turned to A in this fashion. As can be seen, above, this results in an exponential relationship between voltage and frequency, as each change in octave requires an additional doubling or halving in frequency. An accurate reproduction of this exponential curve in modules is difficult in analogue synthesizers because temperature changes and the ageing of electronic components, often referred to as tracking errors, can impact pitch.

An aside: Many Japanese synthesizers, such as those made by Yamaha or Korg, use a system where voltage is proportional to frequency. If A1 = 1 V, then 2A = 2 V, 3A = 4 V, 4A = 8 V. In other words, it takes a doubling or halving of the voltage to result in an octave change.

There are three basic approaches to acquiring modules that can be used with Eurorack. These are 1) assembled systems; 2) DIY from kits; 3) DIY from components. All three of these approaches will be discussed below.

Assembled Systems

Moog in the late 1960s released synthesizer modules Ic, IIc and IIIc followed by the Ip, IIp and IIIp These were followed in the early 1970s by System 10, 12, 15, 35 and 55. These were all extremely expensive, based on a discrete transistor designs. The separate modules – such as oscillators, amplifiers, envelope generators, filters, noise generators, ring modulators, triggers and mixers – were connected using patch cords, which also enabled them to control each other. This produced a distinctive sound that made its way into many contemporary recordings. Production of all these except system 15, 35 and 55 modules had stopped by 1973. These last three lasted until 1981. Moog released new versions of some of these since 2014, but these typically cost US$ 35 000.

The patents and other rights to Moog’s modular circuits expired in the 1990s. With the expiration of these rights, other manufacturers have been able to offer sound clones of these modules, many in the Eurorack format. Since 2020, Behringer has been one of these.

The Behringer 960 sequencer controller replicates the operation of System 55 but using modern components, and built so that can fit in a standard Eurorack case. It is also affordable, at about NOK 1 600.

DIY from kits

For slightly more money, about NOK 2 200, one could also buy a Dreadbox Dysphonia, that was offered as a kit in 2021-11. As with many kits, it was made as a single run. Once the kits from that batch are sold, no additional kits will be made. Dreadbox describes this as buy now or cry later. On 2022-01-19, one was being offered for sale for NOK 4 000. Despite the hype, one can usually expect something similar being offered in the future, but there will be differences, sometimes even improvements.

The main advantage of this kit is that It could be used as a stand-alone desktop synthesizer, or be fitted into a Eurorack. To facilitate both purposes, It comes with a USB to Eurorack power converter. This type of kit is claimed to be well suited for inexperienced DIY construction. Instructions are typically easy to understand, and solder together!

The Dysphonia consists of 13 individual sections that offer an affordable, compact, modular patch system, if one is prepared to build the system from parts. It consists of a single analogue oscillator comes with 4 waveforms that you can patch independently through 3 VCAs = voltage controlled amplifiers, and a 3 channel mixer before being subjected to a 24dB 4-pole lowpass filter and 12dB 2-pole multimode filter. The low pass filter can also self-oscillate to provide additional tones. In addition to an analogue LFO = low frequency oscillator ad envelope, there is a digital modulator providing 4 different modes with low frequency oscillator (LFO), Envelope, Random and CC = continuous control, a MIDI = musical instrument digital interface message capable of transmitting a range of values, usually 0-127. These are commonly used for controlling volume (#7), pan (#10), data slider position (#6), mod wheel (#1) and other variable parameters. This can enhance music, but an over-use of these messages can result in MIDI log-jam, where the amount of data sent exceeds the supported bandwidth. There is also a MIDI-to-CV = control voltage, module which provides analogue to digital and digital to analogue conversions, allowing the module to intereact with a keyboard, computer, phone or almost any other device. There is also a Hybrid Echo module.

DIY from components

One useful source of updated electronic information comes from Elektor magazine. A green subscription provides everything digitally, including back issues. Elektor publishes electronic projects, background articles and designs aimed at engineers, enthusiasts, students and others. It also sells printed circuit boards (PCBs), kits and modules. PCB design work is usually available without charge from their website. Microcontroller and/or computer based projects normally come with program source code and other necessary files.

This is also a good source of synth designs that take advantage of modern electronic components with methodologies that are suitable for hobbyists.

Gear Acquisition Syndrome

One of the major challenges with Eurorack, is that it encourages the acquisition of excessive amounts of gear. Gear acquisition syndrome (GAS) is a real psychological challenge, satirically documented by Steely Dan guitarist Walter Becker (1950 – 2017) in a 1994-04 Guitar Player magazine article (p. 15), where G originally stood for guitar. Because the many providers of Eurorack offer a wide variety of relatively low-cost components, often with specific but limited characteristics, it is tempting to buy just one more! Some people realize compulsive shopping should be resisted. Those who need the advice, will probably not follow it.

The seven key stages of GAS are discussed in a 2022-08-18 Music Radar article. These are: dissatisfaction, desire, ‘research’, the purchase, guilt, acceptance and relapse. Relapse, this last “cruellest stage of GAS can hit anywhere between a year to eighteen months after the purchase, although the time passed invariably depends on the amount of cash spent and the amount of meals you’ve had to eat from a tin as a consequence.” Once again, the article refers specifically to guitars, but also applies to synths, and by extension Eurorack modules.

Another weblog post tentatively titled DIY Synths and currently scheduled for publication 2023-03-25, contains more detailed information about synth circuits, especially from kits.

Dave Smith (1950 – 2022), educated in electrical engineering and computer science at the University of California, Berkeley, bought a MiniMoog in 1972. In San Francisco, in 1974, he made a hardware sequencer = a hardware device or software program that can record, edit or play back music, using note and other performance information, for himself. Then he made three other sequences, and sold them under the name Sequential Circuits. These four analog sequencers could be used with Moog and ARP synthesizers. In 1975, Sequential Circuits went on to make an unknown number of digital hardware sequencers, and then programmers, similar, but slightly more advanced devices that, can change the settings and other characteristics of a synthesizer. By 1976, aided by John Scott Bowen, these had become the Model 800 Sequencer, and Model 700 Programmer.

In 1977, the Prophet-5 started life as a Prophet-10, a synthesizer with ten voices of polyphony. It was unstable and overheated. This, in turn, made it difficult to tune. To construct a viable product, half of the electronics were removed, resulting in five voices of polyphony. It was renamed the Prophet-5. This machine was jointly designed by Smith and Bowen, with Bowen responsible for the sound design. Later, he created most of the Sequential’s sounds and sequences, and much of the User Interface (UI). The Prophet-5 was the first fully programmable polyphonic synthesizer and the first musical instrument with an embedded microprocessor, and a programmable memory. This allowed users to store sounds and access them instantly. It eliminated the need for a synth to be reprogrammed after even minor experimentation with sound. The Prophet-5 was especially praised for its ability to produce a standard package of familiar sounds. Between 1978 and 1984, about 6 000 units were produced.

After this, additional products were made including the Prophet-600 released in 1982 with a musical instrument digital interface (MIDI). In 1987, Sequential faced financial difficultires. It was purchased by Yamaha, who shut it down in 1989.

Smith then began working for Korg on the Wavestation synthesizer. In 2002, he started Dave Smith Instruments. That same year it released the Evolver synthesizer. In 2008, it released the Prophet ’08, an affordable eight-voice analog synthesizer. In 2015, Yamaha returned the Sequential Circuits brand name to Smith. In 2018 Smith released the Prophet-X, which featured sample playback and digitally controlled oscillators. On the 40th anniversary of the Prophet-5, (2018-08-31) Dave Smith Instruments rebranded as Sequential. Despite the release of a newer version of the Prophet-5 on 2020-09-30, it was announced on 2021-04-27 that Sequential had been acquired by Focusrite, a British audio company known for its audio interfaces.

Finding a suitable Prophet

In the text below, prices are stated in Norwegian kroner (NOK). To aid in conversion 1 CAD = 7.46 NOK; 1 € = 10.12 NOK; 1 USD = 9.45 NOK on 2022-06-04, on the date of this post’s publication.

Selecting a suitable Prophet is dependent on a person’s intentions and wealth. Those with the economic means who want to acquire an investment with extreme growth potential, probably should have bought an original Prophet-5 at least twenty years ago. If they are content with an ostentatious machine to intimidate others, these machines still offer opportunities.

Those a few rungs below on the economic ladder, content with impressing others, may want to consider a model, currently being made, a Sequential Prophet-10 Rev-4 Synth is being produced. The company is now owned by Focusrite. The synth costs about NOK 45 000. Its specifications include the use of some dated, but genuine, components, along with modern replacements, retaining the sound of the original Prophet-5, but with ten voices.

Musicians who simply want the sounds of a Prophet synth can usually obtain these cheaply, by using a clone or a virtual instrument.

One clone is a Behringer Pro-1 (NOK 3 000), a fairly rudamentary synthesizer based on the sounds of a Prophet-5, but with a single voice. It has numerous specifications that only synth fanboys understand or care about. There are claims that Behringer released a sixteen voice Pro-16 in 2021. I have not been able to find any information about it.

In terms of virtual instruments, Bowen worked for Native Instruments, to develop their Pro 5 software synthesizer emulator, released in 1999. It was followed by the Pro 52 in 2000 and the Pro 53 in 2003. He also contributed to Creamware’s Prophet and Prophet Plus emulators in 2003. Arturia released the Prophet V, in 2006. There are also totally free virtual instruments that can do almost the same, but these usually come without any guarantees.

For those more interested in experimentation than reproducing a marketable sound product, attention is directed to the Notes and Volts YouTube channel.

Note: Dave Smith died 2022-05-31.