The µBermuda is an updated version of the Bermuda VCO. It features a hard sync input that is useful for preciously locking the frequency & phase of multiple VCOs together. Or for mismatching synced frequencies to the point that new timbres and harmonics are introduced. The µBermuda is 2hp smaller. And the FM input is slightly more sensitve (less voltage creates more change).
This is a simple analog VCO. Its “thing” is that the triangle output gets AC coupled back into the triangle core, thus self-frequency-modulating itself. New harmonic content results as the shape of the core becomes less definable. Since everything derives from the triangle core, all the wave outputs get distorted. The videos below demonstrate this.
Furthermore, the self mod control is sensitive to speed of knob rotation. If swept slowly there is no notable change in pitch. If swept not-slowly, the movement of that control will result is a momentary pitch swing. This can be “played” for effect and adds bellow or fluctuation to the pitch. If self-mod starts to near its maximum position, the VCO will go slightly flat. This can be noticed near the end of the sine video.
About the sine output. It’s nowhere near a perfect sine, but it’s pretty sine-ish. It is also inverted relative to the phase of the triangle and square outputs. If the sine is mixed with the other waveshapes (through external patching) this serves to cancel out the fundametal frequency in the other waveshapes, and only the harmonics are left. This has a highpass filtering effect and can make useful tones.
The circuit is compensated against temperature related pitch drift, and has good 1V/oct tracking up to about 2-3kHz. Fine tracking adjustment can be done from the front panel via small flathead jewlers/glasses screwdriver. Sub to supersonic frequencies are achieved through regular CV. Without CV, the frequency knob on the panel has a musically useful range of about 10Hz to 9kHz.
- Eurorack 6hp
- current draw 13mA @ +12V
- current draw -13mA @ -12V
- module depth 21mm