todo.txt

* replace YM3438 resistors with 1k or 2.2k, and the Rf resistors of the op amp with 5.1k.  The amplification should be 5.1k/1k at the high end and 5.1k/11k at the low end of the trim pot
* maybe remove the YM3812 trim pot so we can rewire it with a fixed volume at a later date.  Should I maybe put in 1k/2.2k resistors for that chip as well???



* should you move the audio pot to only control the power amp volume and not the line in volume?

* can I add some helpful things to avoid desoldering?
	* ability to bypass the onboard amps?
	* ability to easily swap out resistor values for amp gain


PLANNING:

* should you use an uno or a mega?  It might be good to have more ram for the instruments??
* later revision could have an integrated arduino or STM32
* should you add another type of output, like RCA?
* should you add jumpers or switches to turn on/off certain channels?

* I'm thinking 4 chips is sufficient, AY, OPNx, OPLx, and maybe OPM
* need to buy more YM2151, YM2413, and maybe YM2164 and YMF278?

* chips that could be used
	AY-3-8910/YM2149
	YM2612/YM3438 (OPN2/OPN2C, might need different audio output resistors to work for either)
	YM3812 (OPL2)
	YMF262 (OPL3)
	YMF278 (OPL4?? I don't think I have one)
	YMF288 (OPN3)
	YM2151 (OPM)
	YM2164 (OPP)
	YM2413 (OPLL, maybe overkill)
	SN76496 (but I couldn't get it working on the breadboard)
	YM2608/YM2610