Hi Gang,
Some of the parts (555, TL082, LM13700) will operate on up to +/-18V so you may not have to use additional regulators to go from 15V to 12V. Check the datasheets to confirm allowable operation range. However, sometimes there may be other elements in the design that were based on a 12V source like a voltage reference; so check the design. Also providing a local regulator may help reduce noise and other nasty things.
That said, be careful of the 7812 etc they may require a minimum supply voltage of 15 to 19V. Consider the T92 package for less than 800mA or local regulation or a low dropout regulator to provide greater input headroom.
All the Best,
Brian
Some of the parts (555, TL082, LM13700) will operate on up to +/-18V so you may not have to use additional regulators to go from 15V to 12V. Check the datasheets to confirm allowable operation range. However, sometimes there may be other elements in the design that were based on a 12V source like a voltage reference; so check the design. Also providing a local regulator may help reduce noise and other nasty things.
That said, be careful of the 7812 etc they may require a minimum supply voltage of 15 to 19V. Consider the T92 package for less than 800mA or local regulation or a low dropout regulator to provide greater input headroom.
All the Best,
Brian