I'd say a simple op-amp in non-inverting configuration and gain of 2 should be the easiest and best way to go. Scmitt-triggering it may be useful. The op-amp should have a Vcc of at least 12 V for a Vpp of 0-10 V. Be careful which op-amp you use, because most need dual-supplies for proper operation. If you use only a single-supply Vcc, there are many caveats you should be aware of.

I don't understand how you could use an astable multivibrator to generate a sinewave. The only astable multivibrators I know are the 555 kind that generate sqaure waves.

kundi