Using hex inverters as op amp

[Greg]

Hi, this is probably an example of "a little knowledge is dangerous".

I was wondering if anyone knew if it's possible to hook up 3 hex
inverters (such as from a 4049) as an op amp? I'm thinking 2 inverters
(for non-inverting input) with the output wired to a single inverter's
(inverting input) output. Does anyone know if this would work? I'm
interested in musical applications. I've built Craig Anderton's
Tube-sound Fuzz using the 4049 and it sounds great, that's why I've
started thinking about this.

Thanks,
Greg

 

[R.Lewis]

"Greg" <zaraakNO@SPAMmad.scientist.com> wrote in message
newst2k11ld38pa6tcakl9ikp4bamm728v7fi@4ax.com...

Hi, this is probably an example of "a little knowledge is dangerous".

I was wondering if anyone knew if it's possible to hook up 3 hex
inverters (such as from a 4049) as an op amp? I'm thinking 2 inverters
(for non-inverting input) with the output wired to a single inverter's
(inverting input) output. Does anyone know if this would work? I'm
interested in musical applications. I've built Craig Anderton's
Tube-sound Fuzz using the 4049 and it sounds great, that's why I've
started thinking about this.

Thanks,
Greg

I seem to remember that in the old RCA databook on their 4000 series logic
there was a complete section on the analogue uses of various of their
unbuffered devices.
Unfortunately my copy of the databook is long gone (dunno where) but someone
out there will have one to quote from, I'm sure.

Regards

 

[Harald Noack]

Hello!

we used some 74hcu04 ac-coupled with resistor of 2k2 from output to input to
amplify a 13Mhz signal.

Bye!

"Greg" <zaraakNO@SPAMmad.scientist.com> schrieb im Newsbeitrag
newst2k11ld38pa6tcakl9ikp4bamm728v7fi@4ax.com...

Hi, this is probably an example of "a little knowledge is dangerous".

I was wondering if anyone knew if it's possible to hook up 3 hex
inverters (such as from a 4049) as an op amp? I'm thinking 2 inverters
(for non-inverting input) with the output wired to a single inverter's
(inverting input) output. Does anyone know if this would work? I'm
interested in musical applications. I've built Craig Anderton's
Tube-sound Fuzz using the 4049 and it sounds great, that's why I've
started thinking about this.

Thanks,
Greg

 

[Watson A.Name - \"Watt Su]

"Greg" <zaraakNO@SPAMmad.scientist.com> wrote in message
newst2k11ld38pa6tcakl9ikp4bamm728v7fi@4ax.com...

Hi, this is probably an example of "a little knowledge is dangerous".

I was wondering if anyone knew if it's possible to hook up 3 hex
inverters (such as from a 4049) as an op amp? I'm thinking 2 inverters
(for non-inverting input) with the output wired to a single inverter's
(inverting input) output. Does anyone know if this would work? I'm
interested in musical applications. I've built Craig Anderton's
Tube-sound Fuzz using the 4049 and it sounds great, that's why I've
started thinking about this.

Thanks,
Greg

Well, you can't use an inverter as an opamp because there is only one
input, not two, as in a true opamp.

You can use it as an amplifier, but I've seen very old CMOS chips get
real hot if their outputs are allowed to be in the linear region. THis
is not what they were meant to do; as a result, their performance in
this respect could be unpredictable.