Analogue Dub Siren

spec said:

Yes, very valuable experience- there are standard rules about laying out a high gain (open loop) amplifier. The thing is that it is fairly pernickety and perhaps boring.

It does not matter if the amplifier is inverting or non inverting for audio amplification.

What is needed now is a description of the input signal and source and the required output signal and what is to be driven.

We do know that 12V supply lines are desirable.

spec

Click to expand...

The only thing that is boring for me about this is lack of knowledge
Dont know much about the siren (input signal) it is a analog circuit making sounds. Guess I need some more equipment than the multimeter to figure that out

Something like this?
https://m.aliexpress.com/s/item/32594681066.html

Maybe can be modded with a variable gain

Rorut said:

Something like this?
https://m.aliexpress.com/s/item/32594681066.html

Maybe can be modded with a variable gain

Click to expand...

Just the sort of thing.

The 5532 is a fine sounding opamp too, but not as good as the OPA2134 that AG recommended.

The 5532 is also at its best with 30V between it's supply lines.

No point in modifying for variable gain, just use a volume control. Variable gain is seldom used in audio amps- for good reason.

But you can set the gain by adjusting a resistor.

spec

Thanks for the info spec

Think I was also told the lm358 was ok for siren sounds. Here is another small one, very cheap

**broken link removed**

Throughout this thread I have been thinking, "What is wrong with your siren circuit that causes its output level to be too low?". Maybe the siren circuit should have its output level increased instead of adding another amplifier to feed your amplifier.
You are just guessing about how much gain you need. 10 times? 100 times? Maybe the power amplifier you are using has something wrong with its gain? Then adding a preamp with more gain ahead of the input of your power amp might cause the preamp to have clipping but not enough output level.

Tried to change the output volume on the siren by changing a 100K resistor to a 50K , did not do much and lower resistor than 50K made sound distorted. I tested the siren with two different DJ mixers with same result. I can hear the siren on low volume but when on very loud volume the siren cant be heard