Mini Mu envelope filter troubleshooting

Started by suryabeep, January 04, 2019, 09:14:48 PM

Previous topic - Next topic

suryabeep

C4's orientation is ok, I am not sure how to check whether it is working or leaking.
The voltage between C4 and D2 starts at around 300mV when I first probe it, then decreases steadily at about 8-12 mV/s.
Still in the process of learning, so bear with me if I ask dumb questions :P

rring

So where are you at with this? Is it it still not working for you? Sorry I'm late to the party.. I can help you get this working...The first thing is to get the peak detector circuit working. When you put audio input into the the circuit, the indicator LED should light up. If that is still not working as you originally described, you need to simple inject a DC voltage at the LM358 pin 5 and see if the led lights up. 1 volt will work fine. If this works then we need to work our way back to the input with further steps. If it doesn't work, then we need to look at that part of the circuit and continue

suryabeep

Hi rring! The indicator LED does light up - it lights up (in a dark room) at what I'd call medium intensity if I strum the guitar very hard and lights up faintly at normal strum power.
Still in the process of learning, so bear with me if I ask dumb questions :P

rring

okay so can you measure resistance change on a photocell and make sure that it responding to light(connect a pot to to pin 5 on IC1 (my schematic) and sweep the voltage ). Also sweep the voltage and see if you get filter action with a sound source(don't care about guitar yet). Trying to isolate one circuit area at a time here and make sense of what is going on.