Choosing resistors for audio circuits

[The Master]

I've done a little playing around and it seems the solution was to simply add 1 extra capacitor to turn my extra resistor into an RC low-pass filter. Unfortunately it's started clipping again when the volume is on full but most of my circuits will use an internal preset to keep it just below the clipping point and the volume will be controlled digitally so that's not a major problem.

I swapped the RC filter and the pot to give the same effect but to suit my PCB layout better. I've uploaded an updated schematic and the scope readings for just below the clipping point and max volume.

I will be ordering some 470nF caps soon along with some 0.5W and 1W resistors. It's working so well now with the 0.25W that I think a 0.5W should be enough with the 470nF cap but I'll get the 1W ones as well just in case.

I know I still have pleanty to learn about audio circuits but I've learned a lot from this thread and gone from a fire hazard to a working audio amplifier so I'd like to say a big thanks to everyone who's helped me out

[Charlie]

Sorry I was not clear - RMS is the AC equivalent of DC in terms of work or power. DC Watts is DC Volts * Amps. AC Watts is RMS Volts * Amps.

An RC filter with series R followed by C to gnd, follwed by series R followed by C to gnd is not the same as a single RC with appropriate values. A single RC will have an attenuation slope of 20 dB per decade; 2 stages will have a slope of 40 dB per decade - double the attenuation of unwanted signals.

You can clean up your signal a lot more, although you may not care.

[The Master]

I would like to clean up the signal as much as possible. What values do I use if I have 2 RC filters? If I calculate that I need a 10K resistor and 1uF cap for a single one then do I use 10K-1uF-10K-1uF or would it be 5K-0.5uF-5K-0.5uF for 2 of them?

[Charlie]

I would like to clean up the signal as much as possible. What values do I use if I have 2 RC filters? If I calculate that I need a 10K resistor and 1uF cap for a single one then do I use 10K-1uF-10K-1uF or would it be 5K-0.5uF-5K-0.5uF for 2 of them?

Read this. http://www.electronics-tutorials.ws/.../filter_2.html