Analog synthesizer manufacturers typically adopt one of several standards:
Hz per volt - used by Yamaha and Korg
1V per octave - used by Moog, Roland, ARP and Doepfer
1.2V per octave - used by Buchla and EML
0.32V per octave - used by EMS
0.26V per octave - used on oscillator 3 of the EMS VCS3
I've been playing a lot recently with my old Buchlas esp after visiting Japan and seeing some great Buchla performances..
Buchla voltage specs vary a bit between 100, 200 & 200e series.
Not all modules react the same.
So be careful when you first test these sequencers out.
For safety, I start with the lowest pulse setting on my sequencer and see if it will
trigger a gate or envelope, then work my way up
A brief guide :
Pulses first.
Pulses from the 281e are +15 V, for about .5 ms.
Pulses from the 225e and 222e are a 9V to 10 V spike/short gate with a 5 V sustained "gate."
One of the 3rd party modules that I use, the Pendulum/Ratchet has pulses
which are 1 ms long. The pulses can be changed to either 10 V, or about 14 V.
(this depends on what resistor pack is installed).
The 250e outputs a spike of 8.5V. The spike duration is only 0.5ms.
Note: Buchla pulse outputs include a 10v trigger and a 5v gate/sustain and allow pulses to be combined and sustain to be held even while triggering new events.
CVs
CVs are from 0-10 V. So try to refrain from using -ve voltages .
A module such as the 251e outputs CVs between 0.0V to 9.9V
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The precise Buchla audio & CV levels fluctuated over the decades:
100 series Buchla had audio at 0dBV .... roughly 1 volt RMS.
Pulses are 15V and CVs range between 0V & +15V.
Early 200 series Buchla used audio levels of +4dBV... Professional line level of +1.736 RMS
Pulses are 15V and CVs range between 0V & +15V. for early 70's 200.
Late 200 Buchla dropped the CV range to 0-10V. Audio levels stayed the same at +4dBV
Buchla 200e dropped audio back to 0dBV. Pulses are 10V. CVs are 0 to +10V.
100 series Buchla had audio at 0dBV .... roughly 1 volt RMS.
Pulses are 15V and CVs range between 0V & +15V.
Early 200 series Buchla used audio levels of +4dBV... Professional line level of +1.736 RMS
Pulses are 15V and CVs range between 0V & +15V. for early 70's 200.
Late 200 Buchla dropped the CV range to 0-10V. Audio levels stayed the same at +4dBV
Buchla 200e dropped audio back to 0dBV. Pulses are 10V. CVs are 0 to +10V.
The Buchla Polygot manual is a good reference
Here is a brief list of sequencers that can output 1.2V/oct
Expert Sleepers
Disting Mk1/2 (Eurorack)
Disting Mk 3
Disting Mk4
Silent way - software
It runs as a plug-in for your DAW
Elektron
A4 - Analog 4
The synth's sequencer has a very flexible CV/gate
config. I use it with Buchla & well as Korg.
The CVs are digitally controlled which makes for high precision.
Endorphin.es
Shuttle control
PITCH 1V/OCT, PITCH 1.2V/OCT AND HZ/V are
the control voltages available
SHUTTLE CONTROL outputs +5V at C4 note
(the highest voltage SHUTTLE CONTROL can transmit).
Then 1 octave lower C3 will return +2.5V, C2: 1.25V, C1: 0.625V, C0: 0,313V, C-1: 0.156V and the last one C-2: 0.078125V (with pretty bad resolution however).
As you may see, the accuracy in the lower octaves is bad and on the edge of SHUTTLE CONTROL's CV resolution possibilities.
That is why the useful range for controlling such type of synthesizers is roundabout 3 to 4 octaves.
Keith McMillen
QuNexus - keyboard/sequencer
Use the editor to set this to 1 Volt per Octave, 1.2 Volts per Octave (Buchla) , or Hertz per Volt
Kenton
Pro-solo
Pro-2000
Modular Solo
+ Polyend
Polyend 2 - eurorack MIDI to CV converter
1-4 Gate (0-5V or 0-10V),
1-4 Pitch (0-10V, V/Oct, Hz/V, Buchla standard 1.2v/oct).
A really handy module that allows you to use the sequencer
of your choice
XOR Electronics
Nerdseq - eurorack tracker sequencer
Synthstrom
Deluge - synth/sequencer
A number of settings are available in the settings menu.
Each CV output may be set, in 0.01V increments, to any value between 0.01V and 2.00V per octave, or to “Hz per volt”.
Squarp
Pyramid sequencer
CV V/oct or CV Hz/V,
or exotic voltages like 1.2, 0.32 or 0.5 V/oct.
Korg SQ- 64
CV out can be: Hz/V, 0.26V/oct, 0.32V/oct, 1V/oct, 1.2V/oct -
with voltage bias adjustment and 0V reference note adjustment (per track)
Gate out: 10V, 5V, V-Trig, S-Trig
Mod out: 0V-10V, voltage bias adjustment
Track D - the drum track has 16 possible tracks, via MIDI with 8 drum trigger
outputs for working with modular gear.
Sequentix
Cirklon sequencer
Its a MIDI sequencer but the
CVIO option adds 16 CV and 8 gate outputs.
The CV outputs support 1V/octave, 1.2V/Oct and Hz/V modes plus portamento/glide and micro-tuning options.
The gate outputs can be configured in 5V v-gate or S-trig modes.
Pattern lengths are up to 256 steps.
Orthogonal devices
er101-102
This is a eurorack module, inspired by the Buchla 251e sequencer.
Its much cheaper than the Buchla version, but offers many of the same features.
Its perfect for a Buchla-TipTop euro system
- voltages between 0.000-8.192V at 2mV increments can be dialed in
- 4-track sequencer
- stepped and smooth voltage transitions
- each track has 3 outputs: 2 CVs + 1 gate
- each track has its own adjustable loop points
Arturia
Keystep pro
By default, the transmitted pitch voltage is compatible with the 1.0 V per octave standard,
To use a 1.2 V per octave or a Hertz per Volt (Hz/V) standard you can change the corresponding setting in the MIDI Control Center.
(Note: the simplier Arturia Keystep only does 1V/oct & Herz/V with the current firmware)
Microfreak
By default, the transmitted Pitch voltage is compatible with the 1v per octave standard.
To use the 1.2 V per octave standard, you have to change the corresponding setting in Utility>CV/Gate>Pitch Format or in the MIDI Control Center.
Gate signals can also have different output ranges (S-Trig, V-Trig 5V, V-Trig 10V). These too can be changed in Utility>CV/Gate>Gate Format or in the MIDI Control Center.
T-1 Algorithmic sequencer (Torso elecronics)
Added 1.2v/oct for compatibility with Buchla gear. CV voltage for pitch outputs is wrapped on both ends of 0-5 volt limit
Future Retro 512
The 512 is a capacitive touch keyboard, packed with a unique blend of truly musical features to enhance your creative experience.
The 512 is available with or without the optional rack ears that allow it to fit in a standard 19" rack enclosure, taking up only 4u spaces.
Why is capacitive touch better? Quite simply, eliminating mechanical moving parts found in traditional keyboards makes a product that will never wear out, as mechanical keyboards do. No more intermittent key contacts, or failed aftertouch circuits to worry about! In addition, capacitive touch provides a much faster response time for playing notes, and allows multiple forms of expression to be executed by the performer.
There are five main functions of the 512. It can act as a keyboard, arpeggiator, sequencer, MIDI to CV converter, and MIDI to MIDI converter. The 512 can control both MIDI and CV/Gate synthesizers simultaneously. Pitch, Pitch Bend, Mod Wheel, Gate, Velocity, Aftertouch, and Clock are all available in both their MIDI and CV form.
CV's follow the 1V/Oct standard with positive polarity Gate signals, allowing the 512 to control the majority of analog synthesizers both past and present. The 512's CV output is adjustable providing a range of .47V/Oct to 1.34V/Oct. This then allows you to control other CV standards such as the 1.2V/Oct synthesizers used in Buchla and EML brands as well.
OXI ONE
- V/Oct (most modular and semimodular systems). From -3 to +5 V.
- Hz/V (Korg standard pitch tracking). From 0 to +5 V.
- 1.2V (Buchla standard pitch tracking). From 0 to +5 V
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Final thoughts.
After searching the net, it seems like there are lots of sequencers that you can use to sequence Buchla gear. You can of course use a real Buchla sequencer (of which there are many) , but if you are short of real estate in your system, then an external sequencer is a Ok solution.
In addition, if you have a Buchla Midi to CV converter such as the Bucha 225e or 225h you can of course use a midi sequencer.
