ok. I give myself an answer ;-)
Yes it works and it works very well. That means, now I can tune my
NES easely, even while playing.
I used an LT1799 Oszillator Chip as Crystal replacement.

greets to all NS moders
electra_toy

--- In nesmodifications@yahoogroups.com, "electra_toy"
<electra_toy@...> wrote:
>
> Hi
>
> I just have bought an MIDINES cardridge and noticed that
unfortunately
> the Pitch is way to low (about 80 cents) on my European console.
> I wonder if it's because the cpu clock on PAL consoles is lower
than
> on NTSC consoles.
> NTSC consoles works with a 21.47727 MHz Crystal and clock will be
> devided by 12 = 1.79Mhz cpu clock
> PAL consoles works with a 26.601712 Mhz Crystal and the clock
devider
> should be 16 = 1.66 Mhz cpu clock
> Now I wonder if I would replace it with an 28.64 Mhz Crystal,
should
> the console still work ? No problem if I cant have a picture,
because
> I just need the sound (but with correct Pitch)
> And I also wonder if someone made a cpu clock mod on european
console,
> to play US games with adjusted sound pitch ?
>
> greets
> electra_toy
>