DOEPFER A-110-6 TRAPEZOID THRU-ZERO QUADRATURE VCO

A-110-6 is a Trapezoid Thru Zero Quadrature VCO. The module is based on an idea by Donald Tillman from 2003 but has been revised for the use of modern electronic circuits (no OTAs/CA3280). Because of it's unique trapezoid core it's totally different compared to other VCOs. But the trapezoid core is not the only specialty: it is also a quadrature VCO and features linear thru zero frequency modulation.The term "quadrature" means in this connection that the oscillator outputs two trapezoid waves with 90 degrees phase shift. The same as sine and cosine of a standard quadrature oscillator like the A-110-4 or A-143-9. These waveforms are called TRASIN (trapezoid sine) and TRACOS (trapezoid cosine).The term "Thru-Zero" means that even "negative" frequencies are generated. But this a bit a misleading term as negative frequencies do not really exist. "Negative" means in this connection simply that the TRASIN/TRACOS waves will stop when the linear control voltage reaches 0V and continue with the