Heated chip with music from outer space vco

[zipzap]

Hi
Has anyone used the heated chip methode with rays vco design?
http://www.musicfromouterspace.com/analogsynth/August2003VCO.html
I don´t get the right tempco (at a price i want to afford) so i thought i could use the method doepfer uses in their A110 with the ca3046.
http://www.doepfer.de/a110_tec.htm
Should work more or less and i think if the chip gets a nice isolation jacket it shouldn´t coast too much current (hope so).
Only thing i´m concerned about is trimming the vco, because the trimmers in rays and the doepfer vco show some little differences. Shouldn´t matter, right?

[toppobrillo]

heat it!

[zipzap]

i take that for a yes.
Tell you how it worked when i get to it. Another thing is the fet which i can´t find anywhere around here. Supposed to be a mpf102 or 2n5457. Do you think a bf245b will work?