@cesar

Im working on the saawtooth part of the circut now (labeled n the photo) and reached an empasse, ts kind of hard to make a way to be able to select the mode (square, sawtooth, sine) because of the way the frequanc selector works, i tred to have a switch conected to all the buttons so f i need square wave its conected to 3V but if i need a sawtooth its conected to the negative pin of the op amp. The problem is this; even i select where the buttons connect i cant choose wich generator works wiithohut havng a bunch of redundant switches any suggestion are welcome

i found the chematic for my sawtoooth wave maker and i calculkated the resistances

I finished the square wave generator part of the synth, calculating the aproxiamte resistor value for each button to get the frequencies i was looking for, and i started looking for sawtooth generator ciruits but i found very lttle results that actujally showed that, maybe ill try to build my own

i started by build the square wave generator using a 555 timer, using a schematic online for a near 50% duty cycle, anf changes frequecy based on C and the r2, i got stuck here trying to do the math to see what resistace is needed for the frequencies im looking for (261.63 Hz, 293.66 Hz, 329.63 Hz, 349.23 Hz, 392.00 Hz, 440.00 Hz, 493.88 Hz)