Going to a more positive path . I was looking for a power supply for my faulty old Micro synth and I decided to give a closer look at the schematic. The delay or “attack” circuit is quite nice . I made a nicer schematic for it to help my understanding .
It’s an interessting and quite simple delay circuit (or “attack” as labelled on the microsynth). All the effect is dependent of C30 charging time. A “discharge” time pot could also be incorporated by adding a potentiometer with D1 to control the discharge of C30. It’s simple circuit using bipolar transistors as switch devices.
Its smallness makes it perfect for other effects. Imagine a Wah controlled by attack ? or a LFO fading in depending on how long the input signal is applied ?
And this a thing that I may add to my next synth idea. Feed an LFO into a VCA controlled by this attack circuit and you get a LFO with a delay . The oscillation doesn’t start as soon as you play a note but fading in slowly depending on the attack value . It may even not appear on short notes.