george2525
- Jan 30, 2015
- 170
- Joined
- Jan 30, 2015
- Messages
- 170
Hello
I am trying to make a music synthesiser and this is the AR part of the circuit. My values may not be very precise as its just a multisim version at present but I think the general idea seems ok.
Everything before U4A is just my power supply and Key A is to simulate a gate.
The output shown goes from about -4.01V to + 3.07V . Im not sure why it is not symmetrical but this is not a major concern right now.
The problem is that I dont know how to handle the negative output with regards to controlling a VCA at the output. I have attached a random Jfet here but ideally I want to connect a LM13700 OTA here. Should I be biasing the last op amp to raise the negative voltage to ground here?
Im realy confused about how to link this circuit to some kind of VCA that I assume should function in a range above ground. I say this because in my experience using synths the AR/ADSR plots always seem to be above or equal to ground.
I hope my question makes sense.
Thanks for any help
![ARout.PNG ARout.PNG](https://maker.pro/forums/data/attachments/27/27693-a41689509e899d424e87d697a333c444.jpg)
I am trying to make a music synthesiser and this is the AR part of the circuit. My values may not be very precise as its just a multisim version at present but I think the general idea seems ok.
Everything before U4A is just my power supply and Key A is to simulate a gate.
The output shown goes from about -4.01V to + 3.07V . Im not sure why it is not symmetrical but this is not a major concern right now.
The problem is that I dont know how to handle the negative output with regards to controlling a VCA at the output. I have attached a random Jfet here but ideally I want to connect a LM13700 OTA here. Should I be biasing the last op amp to raise the negative voltage to ground here?
Im realy confused about how to link this circuit to some kind of VCA that I assume should function in a range above ground. I say this because in my experience using synths the AR/ADSR plots always seem to be above or equal to ground.
I hope my question makes sense.
Thanks for any help
![ARcircuit1.PNG ARcircuit1.PNG](https://maker.pro/forums/data/attachments/27/27692-5e75bec41ff95062ab4a4a0668e22b14.jpg)
![ARout.PNG ARout.PNG](https://maker.pro/forums/data/attachments/27/27693-a41689509e899d424e87d697a333c444.jpg)