BJT transistor amplifiers

[audioguru]

You can't connect anything more than 10u to an 8R speaker on a 555.

Are you talking about using a tiny 10uF highpass filter feeding the 8 ohm speaker? The cutoff frequency is calculated to be 2kHz but it will acyually be maybe as low as 1kHz due to the inductance of a speaker causing its impedance to be higher.

The output swing of a 555 into a low impedance with a 6V supply is only 1.5V peak with a max current of 188mA peak. So low frequencies can be used with a huge output coupling capacitor.

 

[colin55]

Simply connect the 8 ohm speaker to a 1000uF coupling capacitor

You are stating something that you have never tried.
Try these things before you post them.
Putting 100u on the output distorts the output considerably.
Putting 1,000u on the output makes a complete mess of the waveform.
You cannot use more than 10u to get a reasonable representation of the output of the 555.

 

[audioguru]

"Putting 100u on the output distorts the output considerably." But I am not putting a capacitor as a load, I am using an output coupling capacitor to feed AC to the speaker.

The 555 is spec'd to have an output current of 200mA. With a 6V supply, a huge output coupling capacitor and an 8 ohm speaker the output current is less.

The output is a square-wave that has very high distortion. It sounds like a cheap buzzer.