cd4046be vco quieter than ne556n vco on my breadboard

[spacesynth]

Hiya, I have placed my cd4046be and ne556n on my breadboard to create two simple vcos, all connected to a 0.2 watt small speaker and a 9v battery. The ne556n set up similar to a atari punk set up but is louder than the vco on my 4046 which is a pain. My quetion is how can I increase the volume on my 4046 so it's the same volume as my ne556n. I'm wracking my brain on this one so any help would be most appreciated. P.S. please reply with untechnical info please as i'm new to all this, many thanks.

[Grumble]

4046 output at 10 volt = 2mA
556 at 15 volt Sink 100 mA Typ, Source 10 mA Typ
That will explain the difference in volume when using a low impedance loudspeaker.

[blue hell]

And so ..

The easiest way to get rid of that difference would be to weaken the 556 signal with a series resistor .. to be experimentally determined to be be like 40 to 200 ohms .. although those values are just coming from my thumb and may be wrong (but they will not hurt)

A somewat less easy (but probably more systematic) way would be to use an amplifier, or speaker driver .. which would give a high impedance input and a low impedance output todrive the speaker. The high impedance input would make it depende less on the output drive capabilities of the circuits toconnected to it's input.

There are IC's which implement amplifiers that are able to drive a loudspeaker. But you could also weaken your signals a factor of 10 or so (with two resistors) and send them to a stereo audio amp driving (a) speaker(s).

[spacesynth]

Hiya, many thanks for your help. Somebody on 'mod wiggler forum said that logic ic's are normally quieter than 555/556 chips. So I may just use a few logic chips connected to a 386 little gem amplifier and two mini 0.2W speakers. Do you think that would work ok? On my previous 556 noise synths I had two 0.2W speakers connected directly to those IC's and they've worked great for the last 7 years.[img][/img]