Hello. Thanks for the idea. Your schematic is from Studio Chaos. I want to make Marekko Chaos. The circuit diagram is different. The secondary is not grounded in the attached image schematic. The output from the op amp is connected to the secondary center tap. 　 The center tap of the primary is conn...

know here I live in Japan so I have to buy $200. I can't buy that much.

Hello. I'm looking for xicon's 42tm117-r. Please tell me where they are sold. "If you have an extra one, I'd like you to give it to me." 　
If you know a compatible product for this transformer, please let me know. I want to create malekko wolftone chaos.

hello. I tested the Doubleur de fréquence circuit on a breadboard. Supports dual power supply using 7660 chip. I wired it according to the circuit diagram and it worked. It produces an octave fuzz that sounds a lot like an octave up sick box. In addition to germanium diodes, I have tried 1n4148 LEDs...

hello. I tested it with a circuit simulator. Q1 has led Q2 has 100k resistor and Q3 is 1n4148. I put 40hz in the input and adjusted it so that around 80hz came out from the output. The bias trim was around 1k and the octave sound was good. Q3 can produce an octave even with a 470k resistor, but the ...

hello. I am also testing on a breadboard. I don't have Q1's mpsa13, so I created Darlington with 2n3904. Q2 is 2n3904 and Q3 is 2n3906. All three LEDs are red LEDs. When I changed the LED of Q3 to 1n4148 as a trial, the sound became rough and powerful. It seems that the octave output is not much dif...

hello. I would like you to redisplay the circuit diagram.
Thank you very much.

Hello everyone. I made funk hmachine. I first made it with lm358 instead of 1458, but it didn't work. After all, I'm using two 741s. It was This time, we modified the wah operation so that up mode and down mode can be used. An inverting circuit was added in the middle of the envelope circuit to inve...

Thank you for your reply. Thank you for your advice. For the time being, I made it according to the circuit diagram and layout, but it does not work well. I am thinking of reviewing the specifications of the parts again. First of all, I would like to improve the accuracy by changing the resistance t...

bmxguitarsbmx I adjusted the LED current, but I can't adjust it to the range of 5mA to 20mA. Currently, I am referring to Mad Bean's Naughty Fish. Adjusted with a combination of 5kpot and 330Ω. The photocoupler used is lcr-0202. When down, 5kpot is the minimum (330Ω only) and 1.74ma in silence. You ...

Bumblebee Thank you for the article. bmxguitarsbmx The current of the output of the LED drive was measured. In the up mode, the silence state is 0.27ma at the maximum when playing at 0.04ma. When you stop playing, it will drop from 0.27ma, but it will take a long time to change the sound quality due...

bmxguitarsbmx The second section is to switch the LED driver from non-inversion in "up" mode to inversion in "down" mode, but since down is a + input, isn't it non-inversion? Is it necessary to switch the range switch when switching down and up? I tested it again and it feels lik...

dear bmxguitarsbmx thank you for your reply. I'm flipping the switch in two places, but I'm having problems. It works with down, but up doesn't. Does the capacitor in the filter section operate at 1n8f and 2n2f? It seems that there is a slight change in the sound when listening carefully in the up m...

Hello rrroo. I also made Mutron, but I have a problem. down mode works, but up mode doesn't. There seems to be no change even when listening to the sound. You said you adjusted the bias, do you need to adjust it to a value suitable for up and down each time? Did you make the capacitor of the filter ...