Doepfer A-147-2 VCDLFO

Combination of a voltage controlled LFO (successor of the A-147), a VCA and a voltage controlled delay unit.
All three parts can be used individually but in combination you can (very easily due to normalizations) fade in the LFO after having received a gate, e.g. for a delayed tremolo or delayed vibrato.

The LFO has four wave forms (sine, triangle, square and sawtooth), it's frequency can be voltage controlled and the LFO has a reset input.
Voltage level ranges: -4V to +4V for triangle, sine and square and 0-8V for sawtooth. Frequency range without CV influence: 0.0005Hz to ~200Hz

The VCA has a linear curve and can be used as a voltage controlled attenuator or as a voltage controlled polarizer.

The delay has to be considered an attack-only envelope with a linear characteristic which is fired when receiving a gate at the "delay reset" input. The delay time (or the attack time to be precise) can be controlled manually or with a voltage.

and now to the combined use: The LFO's triangle output is normalized to the VCA's signal input. the "delay" envelope output is normalized to the CV input if the VCA. If now the delay receives a gate the attack envelope is fired, the rising voltage slowly opens the VCA and thus the LFO's amplitude is rising. Voilá, we have a delayed LFO which we can use for tremolos when connected to another VCA or for vibrato when connected to VCO pitch or for whatever you like.