my question is the following: you wrote, it is designed for 1V input. But I want to use this circuit after a Booster stompbox, which gives an output signal of about 9V. Is it enough to change the R4 with a TrimPoti, to scale the input voltage?
R4 is not a volume control. The circuit as shown works poorly with a max input of only 1.25V. It is shown on the datasheet of the LM3915 with a max input of 10V. A resistor is added between pin 7, pin 8 and ground so that the pin 7 reference voltage is higher but it must be at least 1.5V less than the power supply voltage.
LED vu meter for 9V ?
Posted - Apr 15 2010 : 10:00:38 AM
