The E300 Ulta VCO is based on the 5U MOTM-300 VCO with modern improvements and added features.
Introduced in 2000, the MOTM-300 was based on a sawtooth core designed by Dave Rossum and used in the EMu modular. Since that design was already 25years old, we improved the performance by using 0.1% 25PPM resistors, newer op amps with low temerature drift, and other things. But technology marches on, and now in 2019 we decided to get back together and re-design the sawtooth core to take advantage of today's improved silicon and passive components.
The E300 still uses precision, low drift resistors, adding improved C0G ceramic timing caps, the latest in low drift and low THD OPA op amps, and a new, unique triangle waveshaper that generates 'glitchless' triangles and sine waves.
The MOTM-300 was very sensitive to the rise time of external VCOs used to sync, and the E300 uses a much improved sync/triggering scheme to allow any signal, with fast or slow edges, to reliably force sync.
We decided that a more useful feature not in the MOTM-300 was a switchable -1/-2 suboctave (square wave) on a dedicated output jack.
Height 3U (128.5mm)
Width 14hp (70.8mm)
Depth (with power cable attached) 30mm
Power 16-pin Eurorack (53mA from +12V, 28mA from -12V)
CV input range 10Vpp (-5V to +5V), DC to 10KHz
SYNC Input 50K nominal input impedance, trip point is +1.1V
Audio Output 10Vpp (-5V to +5V), 14Hz to 15.5KHz frequency range (panel controls). Overal range is 0.5Hz to 40KHz
Linear FM AC coupled, sensitivity is 50Hz/V
Warm-up Time The circuitry needs to be powered for 30min to achieve the published tracking and drift performance
Temperature Drift (24hrs) @ 440Hz 0.15Hz, maximum, ambient temperature 15C to 35C (59F to 95F)
Tracking (assuming ideal 1V/Oct input) 0.25Hz maximum, 25Hz to 3200Hz, +-3 cents 3200Hx - 10KHz