Model 23: LEDs be gone
2008-02-11 by (i think you can figure that out)
Guys, The M23 circuit is completed, and making final cuts to the prototype I've elected to can the tap LEDs. Pretty lights that serve no real purpose. Thing is you really can't 'see' the voltages walking across the outputs. You see them changing in intensity, but in most cases it's too little to really make a noticable difference. By ditching them we'll save the part and assembly cost of a quad op amp, a socket, four resistors and four LEDs, not to mention the time it takes to punch those four holes. The PCB gets smaller...it's all good. If there was a way to to incorporate them without a voltage follower (Op amp) drive, I might consider it, however if you're going to have them, at ten to the 13th input resistance this is the only way without causing a noticeable droop on the output taps. Right now I'm at less that 7 millivolts inaccuracy, which is really good and it would be insane to sacrifice that for lights. My main concern is the what you put in comes out so it can be driven by a keyboard or quantizer wothout making your cringe. So the LEDs are gone. - P