Buchla

Electric Music Box

This is my instrument, mainly equipped with contemporary clones of the Buchla 200 series (Bj. 1970-82). The low count of Buchla-modules (e.g. in comparison to the Eurorack) appears as being rather limited (almost like a de-individualization), nevertheless it shows instrumental charm and unmistakable character, which however isn't limited to a sound.

Clones have got the advantage of not having 45 years usage on the clock. Partly also lack or weaknesses have been hurdled. How the differences to the originals are in detail, I cannot judge. I am hugely happy with these modules.

Buchla Modular Series are roughly divided into the 100-Series (60s), 200-Series (70s) and 200-e-Series (since 2005). In the 80s there were still the 400- and 700-Series, which are however extremely rare.

One point why these modules are so interesting and different is, among other things, the fact that mixing (audio) takes a "different rank". Most functions are designed for adjustable weights. Also, very beautiful distortions are produced - almost an extension of the Waveshaping, the other Buchla specialty. Very intuitive. I've had a lot of synths - none of them has tied me like this. A "royal instrument".

Don Buchla

1937-2016

  • With this format I'd like to begin with the person Don Buchla (1937-2016). He is (for me) one of the “Big Four”, which are Don Buchla, Peter Zinovieff (EMS), Robert Moog und Alan R. Perlman (ARP) - they might have appeared on the scene also in this order (ca. 1960-70). I think, all four had assistance of important coworkers, whose existence shouldn't be unmentioned. Such things are developed in the dialog.

    Don Buchla always appeared early with his developments - the modular 100 series was e.g. already introduced in 1963/64 (picture on the left/with the Maestro - photographer unknown). For several reasons the company had never achieved the “commercial break-through”, which surely has to do with the fact that Moog and ARP found a broad group of buyers for Rock and Pop music particularly with smaller stage-synthesizers, while Buchla operated with composers and universities, which required completely different conditions/biases. Furthermore, synthesizer were already expensive, Buchla however was very, very expensive. Since Don Buchla, the name giver and creator of this format, perceived the term “Synthesizer” as misleading, he called his instruments “Electric Music box”.

    The instrument behaves amazingly similar (LPGs) to an acoustic instrument and is very pleasant and intuitive to control. The module panels were usually designed first at Buchla, which is very unusual. The size of the modules (4U), the functional density, the physical distances between the controllers and the arrangement of the switches / controllers are the most successful for me (compared to other formats). The intuitive access is additionally supported by the striking arrangement and the easily distinguishable appearance of the modules. Because of the different layout (Waveshaping/LPG) and the California origin, the term “Westcoast” established for these instruments.

Buchla 200-e

The current Series

    A very nice system - unfortunately not cheap: the pictured Case (18U) costs depending on the configuration from $ 22.000.- (configurations are possible up to more than 30.000). A very adored instrument! Derived from the options almost without competition. I have little experience with this system and can only describe my onetime "experience" - it wasn't that positively, but the report still includes "neutral" information on the System 200e.

    In spring 2012 I wanted to start with a Buchla instrument - but with the e-Series. After trying a Skylab (10U) no joy came into existence. Processing seemed suspect, many knobs felt very shaky. 2 of the 10 modules did not work, i didn't like the sound of the 261e (compared to the previous series' oscillators) and unfortunately it was the only built-in VCO.

    But above all, the (quite interesting and unique) Preset Management is in my way, because I just want to do this with Max. It would be a completely controlled sub-level that would bring only more complications to my work, I would also like to avoid modules with firmware. The e-Series is also highly adapted to the Random and Sequencer Pulse-world, witch is quite far away from what i would like to do. There are much more Pulse I/O's in the e-Series, as in the precursors - they are also used for calling up Sub-Presets directly in the modules. In the Triple Morphing Filter 291e are e.g. 3 "Nodes", each with 8 "Stage Numbers". That is an integrated Step Sequencer with 8 steps and 3 buses which is used for storing the 3 Filter Values. With Pulse it is "stepped" and with CV interpolated (I think it's interpolation and not morphing). Again - this I want to do with Max/Computer.

    The e-Series has grown in terms of performance and compressed in size at the same time (compared to the 200 series). The Dual BPF 291 has become a Triple Morphing Filter 291e. The System Interface 227e has shrunk and still offers additional options (the only e-module in my system). A highlight (for me) is the Matrix-Router, but (fortunately) probably i do not need it.

    So - a great concept - but not for me. Maybe someday more e-Series will show up in my system but i prefer building my base system on the basis of the 200 clones, which I also prefer sonically.

Buchla-Details

Idiosyncrasies
  • Buchla modules (4U) make no synthesizer but an Electric Music Box. Since Don Buchla did not consider keyboards as ideal controllers, there were alternative control modules from the beginning - for CV, there were different Touch-Plate Attenuator variants and very individual Sequencers, for audio more complex Matrix Mixers.

    The Audio Connector Format is the rare Tini-Jax .141 from Switchcraft. Tini-Jax is minimally larger than 3.5mm Mini-Jack and looks similar to the confounding. Tini-Jax plugs are available in metal and plastic versions.

    Mini-Jacks do not sit quite so firmly, but function also and can therefore be used without hesitation on the Buchla.

    Buchla uses Line Level 0dB/600 ohms for Audio (instead of +12dB/150 ohms, like Eurorack).

    Buchla uses 1.2V/oct (instead of V/oct or Hz/V).

    Buchla Electric Music Boxes work internally with 15V - even if they are supplied with 12V power supplies! The original 100-Series and the very early 200 modules were still supplied with 15V (and partly more).

    The Banana Sockets are subject to a color code. Orange for Pulse Inputs and red for Pulse Outputs, black and gray for CV-Inputs, blue and violet for CV-Outputs.

    The alternatives (Gray/IN and Violet/OUT) are only used when inputs or outputs are in a large number in the module.



    In the 200e series, the buttons are color coded too: the positions of the blue buttons are stored in the preset - the white not.

    A particular peculiarity is the length and strength of the Pulses. The modules (especially in the 200e series) produce very different pulses with different shapes (rectangle/triangle), lengths (0.5ms to 4ms) and strengths (9-14V). I'll go back to this (see: BUCHLA peculiarities in the CV control by other formats).



    Buchla - buchla.com





My Buchla

200 Series Clones
  • Since I prefer the (historical) "200 Series" and for me the programming environment "Max / MSP" is of central importance, I leave out a large range of modules. Just this area also plays a central role, particularly in the e-Series (e.g., Sequencer, Touch Panel, Matrix Router, and Preset Management). This is interesting, but nothing for me - I want to do this with Max. If, therefore, these modules are attractive to many Buchla friends, I have no ambitions to acquire them and will report only on the details of my instrument.

    The top boat has 3U and is Eurorack. It has nothing to do with the Buchla and was simply the best place to accommodate these modules in my instrument - the included Expert Sleepers modules (right) are for the control of the MOTM.

    Due to the Expert Sleepers Module (Audio to CV), the left half of the top Buchla boat is fully crowded with 72TE Eurorack modules. In addition to the Expert Sleepers modules, I have added a Vector Mixer (Joystick), Pedal Interface (Sustain and Expression), Dual VCA, Gate-to-Pulse Converters, two Crossfaders and two A/B Switches. Of course the Eurorack modules have their own Power Supply

Modules

  • Programmable Complex Waveform Generator Model 259

    The "Programmable Complex Waveform Generator Model 259" (left) is a Dual Oscillator with Timbre Modulation.

    In particular, the 259 makes clear why Buchla needs fewer modules. Of course, the circuits are also possible in other formats - but they require 3-8 modules for the same tasks (ie 2x VCOs, VCAs, Attenuators, Waveshaper etc.). The division of Shaping into Timbre and Harmonics with Order and Symmetry came only with the Model 259 and makes this Waveform Generator a truly royal module. The Banana CV-Out of the left Oscillator is another advantage of the 259.

    Buchla VCO's are designed for Frequency Modulation and Waveshapping, and Buchla is arranged "differently" - also modular, but the groupings of the functions are combined in selected combinations in such a way that a basic instrumental characteristic arises.



    Dual Oscillator Model 258 and Model 258v

    The "Dual Oscillator 258" (right) is perhaps "the" classic Buchla VCO. The upper Oscillator is Sine to Sawtooth, the lower Sine to Rectangle. Model 258 has at least three Clone versions, the Model 258r, the Model 258r with historic components and the Model 258v, by Mark Verbos. I have the two last-mentioned versions, which, in all diversity, both have their merits. The Model 258v has CV inputs in place instead of the "Fine Tuning" axes. My favorite is the model with the historic components, because it is somewhat "eggier". ;-)

    What fascinates me about this Double Oscillator is how immensely "straight forward" it is. It raises no questions, has clear playing fields (top sawtooth / bottom rectangle), allows cross modulation and sounds just like the "VCO for the island".



    Harmonic Oscillator Model 262v

    The "Harmonic Oscillator Model 262v" (left) is an additional oscillator with 10 Partial Tones. Apart from the single Outs of the Partial Tones, it (of course) also has a mix output for all Partial Tones. At least Saw, Tri, Square and Pulse have dedicated outputs. The Volume of the Partials can be controlled with the sliders or via CV Inputs (black).

    Since Mark Verbos now has a well-known Eurorack series, in which there is also a Harmonic Oscillator, many will ask where the differences lie. Obvious are the two additional sliders on the 262v. They are not just two sliders: they are two important overtones that extend the harmonic spectrum considerably, because they go beyond the octave (and thus over the "triad characteristic).

    The 262v is better controllable (the Eurorack module is somewhat obscure) and the Euro VCO is based on the Model 258 Oscillator, while the 262v is based on the Model 259 Oscillator. Well - and Euro is 12V.



    Dual Sine-Sawtooth Generator Model 158

    This Double VCO is the replica of the 100 Series (1963-70) Oscillator, the "Dual Sine-Sawtooth Generator 158" - the predecessor of the 258. The 100 Series always appealed to me because of its crudity. The replica does not attain this entirely, but has other advantages, e.g. a much better tuning stability. Also, the 100 Series is not as completely CV-controlled as the 200 Series and therefore needs to be operated more manually. Oscillator 158 is just as straightforward as its successor, but has only the Sine and Sawtooth waveforms, while the 258 provides one Saw to Sine and one Sine to Rectangle. The 158 Oscillator is just wonderful and I do not want to do without it. 158 and 258 have the "famous" Buchla trembling. I like that. Sounds like the big time of electronic music.

    Quad LoPass Gate Model 292c

    Filters do not have the central position, as with VCO/VCF/VCA/ADSR "Eastcoast" systems (Moog, ARP). There are still some. The reason for the less central importance of the Filters is mainly due to two things: firstly, the Waveshaping is to be regarded as an alternative to filtering and Buchla works with Lowpass Gates instead of VCA's - this creates "more natural" ins and outs - overtones change with the volume (or opening of the LPG). Therefore, I would call the LowPassGate 292 as the "typical" Buchla module - it also visually stands out clearly by the diagonally arranged buttons.

    LowPassGates are, technically speaking, VCFA - whereby Filters and Amplifiers are controlled coupled. The module also offers a VCA and a Combo Mode. In the Lopass-Modes, the 292 is one of the most sonorous modules and is highly responsible for the "Buchla sound". At the 292, it is also time to mention the weaknesses, since some applications may require a workaround: the 292 does not completely close and should therefore be lengthened by a Gate or another VCA. Another "weakness" that is perceived as an award, is the Vactrol control: it works through optical resistors and is quite slow.



    Dual Voltage Controlled Filter Model 291

    Model 291 (right) is a Double Bandpass Filter and it's not for everyone. It is very characteristic, therefore easy to recognize and it sounds "very old-fashioned". Such pure / exclusive bandpass filters were the first filters used in electronic music (e.g., the Maihak W49 radio play distortors from the 1950s). Pure bandpass filters are rare today and are usually only part of a "variable state filter". If high and low pass are coupled, they also produce a bandpass. The Vactrol control (light source and optical resistance) of the Model 291 also creates the very own character. Lightguides are rather slower, contrary to the assumption. Vactrol controls have a noticeable inertia.

    Frequency Shifter Balanced Modulator Model 285

    The Model 285 is Frequency Shifter and Ring Modulator. This combination is obvious because for Shifting the waveform is halved and only the positve values are heard. By increasing the offset-voltage the pitch raises (Shift). By connecting the negative wave component, the "counter-oscillation" comes into play and the Ring Modulation effect is generated. I call it effect, because it does not quite correspond to a "typical" Ring Modulation - it remains more to Ring-Mix.

    The Model 285 is a development of Roman Fillipov and is not completely analogous - this can be seen on the 4th power cable, which leads 5V. I'm not really convinced of the sound and find that both, Shifting and Ring Modulation sound better with Max/MSP.





    Programmable Spectral Processor Model 296

    The Model 296 can be used as a Filterbank or, as the name "Programmable Spectral Processor" suggests, in a variety of ways for "audio processing". Actually, the 296 accommodates three modules. The sliders are exclusively connected with the function as a Filterbank. The corresponding outputs are in the middle. Soundwise the most interesting part is the "Programmed Spectrum" area - Audio Out top right. The sliders have no influence here, but the (black) CV inputs. For all 16 frequency bands, there are Envelope Follower CV Outs (blue/violet) and individual Audio Outputs. Almost as an addition I see the Comb Filter - Output in the upper left. The combination of the functions, I/O's and the distribution of the Audio Inputs in "Even" and "Odd" (2x8) also allow a Vocoder-like use of the 296 - that is precisely the Spectral Processing.

    The Model 296 also makes it very clear why Buchla is well suited to work in conjunction with computers, tapes or instruments (the line audio levels are also very beneficial). Buchla modules have the inputs usually located at the bottom and the outputs at the top of the modules.



    Dual Matrix Mixer Model 205

    Even if the "Dual Matrix Mixer 205" completely contradicts my requirements - it is huge and can not be CV-controlled - I could not resist it. Each of the 10 inputs can be controlled on 4 buses. The 4 buses are each in pairs as "left" (1-5), "right" (6-10) and "all" (1-10).

    The Switches are actually Monitor Switches for an internal connection to the Model 227 (System Interface). Input 1-5 are Monitor Left and Input 6-10 are Monitor Right. I use "Monitor-Right" as an Aux output and have a Jack Output attached to the rear of the instrument. There my Pedalboard is connected with Boost, Overdrive, Fuzz, Phaser, Delay and Reverb.



    The Mixer 205 is to be looked at as a sub-mixer. It makes a much better use, especially for the Model 296 "Spectral Processor". The inputs are at the bottom, the outputs at the top, the vertical order are volume knobs for the outputs A, B, C and D.



    Signal Delay Unit Model 277

    The "Signal Delay Unit Model 277" I have for testing in my instrument. This delay is also a special module, because there was never such a thing from Buchla. If I am properly informed, it has been developed by Roman Filipov (Sputnik)! The 1/4, 1/2 and 3/4 outputs are designed to provide feedback.

    I wanted to have a Delay in the instrument to avoid a double ADDA conversion. With the TC Electronic Flashback I already have a Delay and thus also a benchmark. I'm not convinced by the sound of the Delay 277 - although it may have many followers. I think it has to do with the digital components or the programming, because both digital modules (285 and 277) in my instrument can not convince me for the same sound reasons. In everyday life, I tend to use the Pedal of my Pedalboard - also because it can be further shaped by Boost.



    Source of Uncertainty Model 266

    A particularly popular module, which is inextricably linked to the name Buchla, is the "Source of Uncertainty Model 266". This module is probably the model of most Random Generators produced today.

    From top to bottom:

    In the top row are 3x2 Noise Outputs in the steps -3dB, 0dB and +3dB. This is very "nice" and many Random Generators do not offer that. The Random in these generators is generated by White Noise. In the second row, 2x "Fluctuating Random Voltages" are output - even without being triggered. The intensity of the movement is set via the CV inputs or controls.

    The middle "Quantized Random Voltages" and "Stored Random Voltages" represent the actual Random Generator. The lower Outputs give the "main values", the upper ones a more restricted movement.

    In the bottom row is the "Integrator" (left) and bends CV from * 0.1 to * 10. On the right, an S/H unit makes the module perfect! The Pulse outputs are different: the ascending curve and the right descending curve as the trigger (On/Off).

    The Pulse inputs (Trigger) are orange, the Pulse outputs are red. The CV inputs are black and the CV outputs are blue/violet. The metallic sockets are audio jacks - here solely noise outputs.



    Quad Function Generator Model 281

    The "Quad Function Generator Model 281" (left) makes exactly what the name says: it produces four Function curves (AD) in three variations. Once as a loop (quasi LFO), once as a single AD curve on a pulse signal (trigger) and once as ASR, the Sustain as a 5V Gate behind the 10V Trigger (Pulse) is released by 0V (releasing the key) the Release curve. In the quadrature mode, two curves are combined and two, more complex curves can be generated with this module.

    Quad Voltage Processor 254v

    The "Quad Voltage Processor 254" (right) is essentially a doubled "Model 257" and has been developed by Mark Verbos. Incoming CV values can be bent and modulated here according to all rules of art. I have it to keep a little "modular feeling" in the instrument, because I send CV mainly via my Max patches from the computer. So I have 4 computer-independent benders with offset regulators that provide the autonomy of the instrument.



    System Interface Model 227e

    The only module from the current "200e Series" in my instrument is the "System Interface 227e". Mine is however optically (Pot-caps) adapted to the historical "200 Series". I preferred the current Model 227e to the historical 227 because it is only half as big and much easier to get. It also fits even better to current, digital equipment. The 227e offers a Mic-Pre with Envelope Follower, a Headphone Amplifier, a 4 in 1 Submixer and 4 Inputs and Outputs. Each Output can be separately controlled and has its own "Swirl" Generator for 4-channel movement/rotation (direction / rate / amplitude). Output 1+2 and 3+4 each have a 3-band Equalizer and Master Volume. Four Meters with 6 LEDs each indicate the Level. Although the Outputs could be easily replaced by a Max-Patch, the additional functions (Mic-Pre, Submixer, Headphones) would be very missing. Also the EQ's before the exits are welcome.

    The "System Interface 227e" also includes a breakout panel on the rear of the case. The four Outputs are available as 6,3mm TS Jacks and it has a XLR Microphone Input.

Parts

more tiny stuff

    Screws

    Inch screws are always a problem in Germany. To fix the modules I have blue allen screws. They are a little longer than the Buchla screws (but shorter than in the photo), which is very good to me, because the short Buchla screws with short threads like to jump out too easily. Shipping was easy and went very fast.

    Socket Head Cap Screws - Blue



    Pot-Caps

    With the 200 Series, Buchla switched from the black Davies Knobs to the blue and red Rogan Knobs. Although the black Davies Knobs look better visually and also feel better in the twisting, I, triggered by the 205 Mixer, exchanged the Davis Knobs for Rogans on all modules, except for the VCOs because the position line of the Davies is recognized incredibly badly. That "consumes" too much attention while playing. In the dense colonization of the Model 205 (with 40 Pots) also more room for the fingers remains with the Rogans, because they are not as thick as the Davies.

    The red skirted caps, as far as I know, were first taken only for Volume Control, but already on the Easel that rule was broken. (The small red button I've seen so far only at the Easel for Fine Tuning and Waveshaping.) I have however, with my instrument, this color coding taken into account (red = Vol). It relieves and simplifies the interface!


    Shopping

    All these special parts are hard to come by and often the prices are astronomical! Therefore it is all the more pleasing that there is an address in Germany.

    Whether Rogan Knobs, Tiny-Jax, Boats (in different sizes!), Busboards or Patch Cables - also with Sommer Goblin cable.

    WeedyWhizz also offers parts for other formats and builds very nice cases.

    WeedyWhizz Website




  • Tini Jax

    Buchla patch cables are hard to find and very expensive. That's why I first had only Mini-Jack patch cables. Finally, I soldered myself Patch Cables with Tini Jax.


    Because I don't like the cheaper models with plastic cap 740 .141, I decided for the 780 .141 metal (shielded). Tini-Jax .141 plugs are only available from Switchcraft.


    Switchcraft Website


    Since the cable opening of the connectors is only about 5.5mm, the cable selection is somewhat restricted. My choice fell on The "Goblin" by Sommer Cable in the (moderate) colors red and ice gray. Great cable - and it fits perfectly with a shrink tube.

    Sommer Website



    Bananas

    Buchla likes Pomona cables - and Pomona Electronics sells the nicest Banana-patchcables. In Germany they can be purchased via Mouser oder Digikey.

    Also with the cables Buchla follows a color coding.

    Pomona-Kabel on the Digikey Website

    Pomona-Kabel on the Mouser Website


    There are also cheaper cables from other manufacturers. I recommend to choose the plug length of 15mm (there is also 17mm).



Foldable

Original Buchla Case
  • 201e-18

    My Case is a 201-e 18U Case - the same as in the photo above. The "U" units denote the width of the modules. So it fit 3x6 = 18 modules in this case - but there are also double- and triple module sizes. With closed/folded case the three "6U Boats" are closely interlaced and the median Boat is behind the sides of the outer Boats. This makes the removal of the patchcables unavoidable.

    This folding-case concept is so consistently oriented to reduction with a low weight, that it made the "race" against a cabled transport.

    Because of the segregation of CV and Audio (Banana, Tini Jax) and a lower module number the effort of patching is not comparable with MOTM or Eurorack. It's noticeably faster. So you do not forget where cables are patched.

    Buchla Cases have small holes in the boats, which are intended for rear panel connectors. The Breakout Panels are installed from the inside, such as the Back-Panel of the 227e System Interface (see picture). XLR Mic In and 4x Jack (6.3mm) Out. Good thinking!

    The 201e-Case is incredibly light weighted! That too was a criterion for me, but it's not difficult to recognize that the instrument is not well protected. There are special Hardcases, though a lot of air make them much larger than the folded instrument.



    201e-18 Case on Buchla.com




    That's why I got a cover from Hot Covers (UK) for transport: a tailor-made "sweater" that protects the instrument and is super-light and practical. The cover also has a bottom with Velcro closure, which is easily opened and closed. With £ 48.-, this cover was also much cheaper than a hard case! It is enough to send the measurements (of the case) to Hot Covers by mail.



    Hotcovers Website



    Expansion Boat

    The 4HE Boat on my Buchla 201e-18, is a Buchla-6U boat from a third-party manufacturer. The wood sides I made myself. Left (on the back) I have built-in a 4-pin XLR socket for the current. In the 201-18 case I also have such a socket and therefore can connect the boats with a 4-pin XLR cable. Next to the opening in the middle I put a socket with the ground (black) and in the opening is the On/Off switch (Row Power) for the Eurorack modules.

    The grounding of the Eurorack I have laid out externally, in order to be able to easily separate the systems (Buchla + Eurorack) for testing, in case of a humming problem. The ground cable runs to the grounding output of the 201e case.





    Because the case for all modules was too small for me, I had first built a detachable top boat for the Eurorack modules. In the photo on the right is the first version to be seen, which has now been replaced. The closure is easy to see in the picture.

    Meanwhile I have a 3HE boat on top of the 4HE boat. The two case closures on the sides keep both floors bomb-proof and the mount and removal is so simple that it can hardly be increased.

BUCHLA peculiarities

in the CV control by other formats
  • Unipolar vs. Bipolar

    The big difference to other modular formats is the uni-polarity. This means that Buchla only wants positive values (0-10V), whereas Bi-polar systems are ±5V. Both are therefore 10V pp and theoretically a 5V offset shift would suffice. In practice, however, it is a bit different.

    If an external system is connected, it is first necessary to connect the grounding of both systems. On Buchla instruments is therefore a Banana-socket (on the rear). How a suitable cable is set up in the other system is shown on the left, using the example "Eurorack" (16 and 10 pin ribbon cables are the typical connections in Eurorack). This is also the most important step for a good connection.

    Grounding problems would show up through hum. For a quick analysis of such disturbances, I recommend not to make this connection internally, but externally - with a Banana Patchcable. With the external connection, the systems can be electrically isolated from each other for easy testing.

    For connections from the Expert Sleepers modules I made my own adapter cables. Since only the TIP connection must be connected, this was very simple and very cheap. From one banana cable iI created two adapter cables. At the same time, I have introduced the color code "green" for CV cables from Computer.





    0-10V - Unipolar



    CV control brings the ±5V comes into play with the Eurorack Expert-Sleepers Expanders: Buchla wants 0-10V and the ESX-8CV module delivers ±5V in the delivery state. The first thing I noticed was the jumper - it changes the current in ± 9.13V. Taking only the positive values would be 0-9.13V. This would be sufficient for most applications, but two problems remain: The "last volt" is missing, or 0.87V, and, by elimination of the negative values, only 11 bit (0-2047) remain. The resolution is still high enough - nevertheless, I would have rather 12 bit - and this is much easier than originally thought.

    The picture (right) shows that in my instrument are actually only 16 inputs, which absolutely need 0-10V (because they are not connected with the sliders). My compromise is (because I have never used all 16 inputs at the same time), that I use one of five Expanders (8x CV) on the 9.13V / 11bit control. Since (in this case) 10V stand for + 6dB, it isn't painful that I can't generate the 10V. Should I use these CV channels on other modules, I only need to adjust the offset (and may have to remind the 11bit resolution). A very comfortablse situation.

    Since most CV inputs on the Buchla are connected to a potentiometer, the offset can be adjusted with the potentiometer. In most cases this is even better than 0-10V, for e.g. the "LoPass Gate 292", the potentiometers should be in the 0 position to be controlled by CV. By the +5V shift, the 0 position changes to 12 o'clock and this has the effect that the envelope curves can be reduced when the potentiometer is controlled to values below 12 o'clock. I am very much in favor of this.



    A view with the settings of my Expert Sleepers Expanders. It is one ESX-8GT MkI Gate Expander and four ESX-8CV CV Expanders.

    Gates

    On the ESX-8GT MkI one of the level jumpers is set, so 4 outputs have 11.54V output (instead of 5V) - but this is only possible with the MkI modules as they are powered (ESX-8GT MkII modules are passive).

    CV

    Only one ESX-8CV expander is not in the delivery state: the jumper is set to ±9.13V and with the trimmer the output was maximized to 9.54V.



    Buchla Pulses



    Buchla produces very different Pulses. On the Sketch from Chris Muir it becomes clear. One problem is, that the Gates/Trigger/Pulses should not be longer than 4ms. The Pulse of the "Function Generator 281" is even only 0.5 ms short. The second problem is that the typical Buchla "Stepped Pulse" consists of a >8.5V Trigger and a 5V Gate.

    To make it short: the best solution is the Synovatron GT Elements. To the right, the incoming gate is to be seen, and the Buchla Pulses generated therefrom. Audible better!


    Synovatron Website



    1.2V/Octave

    Synovatron has a solution too, but I do not need it, since I work with Max. Only the 4ms at the trigger length are problematic and a swallow of single signals is likely, which can only be controlled by the "Audio Interrupt Mode" (in Max). I don't want that because the name is also program.

    Read more on my hybrid synth page.



    My hybrid Synth