4049 distortion + opamp

[dachshund]

I read the EM article - does this really require that power supply, or are the newer devices such as the "DC Brick" good enough?
And - 12V ??

This is great information - thanks!

[brett]

Hi.
Anything from 5 to 15 volts is ok.
No special supply is needed, but a small AC bypass cap (about 0.1uF) from V+ to ground, located somewhere near the chip, is always good insurance against oscillations (especially necessary if the gain is very high).  You'll see one in most op-amp circuits, too.
cheers

[markm]

Hi.
There's a few "fiddles" with the 4049.
First, the gain of the inverters goes UP as the supply voltage goes DOWN.  Yes, there's no mistake there. Voltage down for gain up.
According to the HEF4049UB datasheet, gain =50 at 5V and 25 at 9V.

Like many people, I use a series resistor in the supply line to reduce power consumption and lift the gain a bit.  A 220 ohm resistor works well.

My experience with the 4049 suggests that a small feedback cap around each inverter takes the harsh "edge" off.  Anything from 10 (hard)to 100pF (soft) works for me.  Also a 220k or 470k feedback resistor makes each stage more "tube-like" than the 1M feedback resistors seen in some schematics.  But, as always, tone is subjective and many master builders have used big feedback resistors.

Soft vintage jazzy tone can be got from a 10x op-amp, a 220 ohm supply resistor, 2 x 220k inverter stages with 220pF caps.

This is the quote I should have inserted yesterday.
Here is the question;
So, if i change the 1M in this schem http://gaussmarkov.net/images/redllama-schem.png
It will provide less gain in the output of the circuit?
Maybe, make the drive less "aggressive" perhaps?

[Mark Hammer]

The short answer is yes.

[markm]

Thank you kindly kind sir he said thanking him kindly