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4049UBE cmos distortions

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5/6/1999 9:04 AM

4049UBE cmos distortions

I just recently read a comment to the effect that "cmos inverters may be used to make an audio amplifier, but they sound bad when powered by more than 6v". I hadn't seen that comment before.

I've made the Anderton Tube-Sound Fuzz several times and never cared much for the tone. Has anyone tried this type of circuit with a V+ around 5v or so? How does lowering the power supply voltage effect tone, other than making it clip with less input drive?

regards, Jack

5/6/1999 9:33 AM
GFR	Lowering V+ to a CMOS inverter will increase the open loop gain (a few dB), increase the output impedance (a lot) and decrease the bandwith (a lot - from a few MHz down to a few kHz). And you obviously have less output voltage to swing. I have graphs and tables with these parameters at various V+ for the 4007 - I can send you a scan.

5/7/1999 6:11 AM
GFR	Lowering the V+ will also make the transfer characteristic of the inverter sharper (more like a step and less like a sigmoid). Also quiescent current draw is decreased.

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