I have followed the instructions as best I can, however I get no input voltage from the input pin, no matter what sound. It always reads 0v on my meter and 0 in the serial port.
unfortunately from lack of parts, I had to vary from the circuit slightly, perhaps one of these are the problem?
-2 100k resistors in series to make 200k instead of the needed 220k
-2 ~2nf caps in series to make ~1.3nf instead of the needed 1nf
-using the bc557b-4 transistor instead of bc558b
-using bc548-4 transistor instead of bc548b
using polarized electrolytic caps might be a problem?
other than that, I cant think of anywhere I went wrong. Does anyone have any suggestions? I dont have access to an oscilloscope
What value are those capacitors? They do not look like 470nF more like 470uF. If they are too high then C4 will absorb all the sound you put into the circuit. The others do not matter as much but that one if it is too big will stop it working.
Can you signal trace and follow where the signal disappears?
re-check your wiring again.
Your transistors orientated right? It's C-B-E (with the flat side facing you).
those capacitors are huge for 0.47uF.
I've used these kind of caps for a VU meter. They're available in this radial format.
The first step in debugging would be to make sure that the dc working points are right. I would measure voltage on the key points (bias divider, b/c/e on transistors, diodes' a/k, etc. vs. ground).
Mark them on the schematic to help people see clearly where the circuit sits at idle.
The first step in debugging would be to make sure that the dc working points are right. I would measure voltage on the key points (bias divider, b/c/e on transistors, diodes' a/k, etc. vs. ground).
Mark them on the schematic to help people see clearly where the circuit sits at idle.
should I go try some smaller 0.47uf caps that arent electrolytic?
anyone else have any other ideas why this isnt working? I'm assuming its a simple fix
