[sdiy] ETI447

[Rönnberg Niklas]

Hi,

I'm working with an old ETI project. The ETI447 is the phaser and you can
find the complete article on Anders' page Cloned Analog Gear, but I can't
reach it right now...
http://omega.tellus.vallentuna.se/anders/
Look in Soundries and ETI, I think that's the right way.

I have some questions about this circuit. I think that the use of IC9, a
4049 CMOS, are quite smart, but why are pin 16 connected to zero reference
voltage?
As far as I know pin 16 are not used in the IC.

I have hade some problems with IC9, and I know that you guys can help me
and explain this to me. I have tried some brand new Philips HEF4049BP and
it's impossible to get these to work. So I replaced the new IC with an old
and dusty MSM4049RS, and everything is getting to work perfect. What's the
difference?

The original circuit uses 741 opamps... Can I replace these with TL071? It
doesn't seem to work as it is, so can I do any modifications to be able to
use TL071? And, what is actually the best low noise replacement for a 741?

Best regards, and I really hope you have better summer weather than we do
in Sweden!

/Niklas