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CV-Sync LFO + S&H




The CV-Sync LFO is a pure analogic Low Frequency Oscillator with wide speed ranges, two advanced sync modes with threshold, 4 classic waveforms outputs ( sinus, triangle, square, up-saw) and a Sample and Hold stage with a Noise generator to produce Random voltages.



- Full CV Frequency with External CV modulation input and attenuator plus a two range switch to get cycles from more than 5 min up to 3Kz or even more (!) Classic V/Hz input.

- Sync input to reset (or lock ) the LFO cycles at any time. The Sync potentiometer set the sync threshold level
This allow to synchronise the LFO with any kind of signals : Gates , Triggers, CVs or even audio Signal for advanced modulation effects and/or complex waveshaping...

- The GATE /TRIG switch provide two different sync modes :

1) TRIGGER mode: to reset the LFO when the signal applied on the Sync input is higher than the threshold level ( the sync pot...)

2) GATE mode: to lock/stop the LFO as long as the signal applied on the Sync input is higher than the threshold level. This mode is great to stop/restart the LFO. It can be used as a gate delay too ...

- The Sample & hold input is normalised to an internal analog noise generator to produce the classic random voltage steps ... The S&H is clocked by a adjustable pulse witdh PW waveform derivated for the LFO's saw output. A direct control of the S&H clock is possible with the Sync input ...The internal noise generator and the PW(M) can be added to the front panel too but they imply a wider panel than my 1U MOTM design....

Scope view of triangle and random outputs

All levels I/O levels are calibrated to be in the 10Vpp range. They are very easy to adapt them to other standards
Frequency ranges can be set as desired by changing a pair of capacitors.
The CV-Sync LFO is made with common and very easy to find parts only .


Schematic , bill of material , pcb...

Download the Cv-Sync LFO schematic + bom ( pdf )

Clic on the picture to enlarge - two CV-Sync LFOs rear view

Demo soundclips

Classic S& H Random demo


On following demos, two CV-Sync LFOs are patched togheter to generate triangle stair waveforms to drive a VCO for automatic melody generation. It use the Sync and the S&h features.

    1. lfo_sh_tristair1.mp3
    2. lfo_sh_tristair2.mp3

Others soundclips with the Sync input + Threshold on more complex patches ...

    1. lfo_sync1.mp3
    2. vcsyn_lfo loop1_cut.mp3


CV-Sync LFO pcbs + Construction manual
are available on order

Marc Bareille © 2008-2009