Hi there,
I finally decided to build the VCLFO 10 from Electric Druid, based on LMNC stripboard layout.
I first soldered it on stripboard because it seemed to be easy, and couldn’t have it working at all (just a little voltage offset when plugged into a filter CV, and all potmeters seem to have no effect)…
So I tried to experiment on test-board (see pictures, sorry for wire colors), it is all the same. I placed 2 LEDs in opposite way of each other at the output of the last OPAmp in order to visualise the swinging +5V and -5V output but there is only a constant output, witch porarity depend on how I tweak the 100k trimmer. I only included frequency, multiple, and waveform potmeter on this test-board.
I tried 2 different VCLFO 10 chips, stored in the same place as all of my chips, that all work correctly as far as I can tell after 5 month of modular build…
If you have any suggestions, I would be pleased to read them ! Thank you guys.
PS : when I accidentally unplugged the 10k resistor between the 2 OPAmps, there were no changes on the LEDs, so I think the OPAmp is just receving nothing from the VCLFO 10 chip.
Hi. I also have an issue with the LED driver circuit from the VCLFO from Meebilt.
When i think of an led driver i normally see a lot of schematics that uses the following setup:
+12v to the collector of a BC547 transistor. A 100k resistor to the base. The emitter goes to the anode of the led, the cathode goes via a 1k limiting resistor to ground. Right?
Or +12v directly to the anode of the led. Cathode goes to the collector. 100k resistor to base (trigger input or whatever), and 1k current limiting resistor to ground. Right?? Works for years now in my modular setup.
Here comes my question/issue.
Whats wrong with this schematic? Why do i keep burning out led’s? The led’s are even not that bright because of the fairly big resistors (3.3k for positive, and 4.7k for negative led’s)
