nikongod

I kind of disagree with DR gilmore's statement that the dyna(whatevers) and some of the others mentioned are op amps. I dont think they have enough open loop gain to satisfy the condition of opampishness. To Dr G's credit, im sure that if his only goal was to make 60dB or more of open loop gain he could have designed another gain stage into the amps only to cancel it out with more feedback later on. there are no free rides: are the more complex harmonics worth it? I'd say not. on that note, not everything in an IC package is an opamp either. With a discrete design you can do a couple things you CANT with an IC. At the end of the day, it boils down to the designer having control over what goes into his (her...) product VS selecting the best part that may be made for something else. 1: You can unconditionally guarantee that EVERY transistor in the gain stage(s) runs class-A no mater what. Many IC opamps run the internal transistors class-A but who really knows how hard? 2: In the design stages you can "roll" transistors in a discrete design, where you just swap the whole IC. 3: Since all of the parts are separate, they can dissipate much more heat individually. You can safely "burn" off a couple watts in the gain/driver stages of a discrete design if thats what it takes to make the amp work well... you only get a hair over a watt TOTAL dissipation with a dip-8 package. 4: If you are designing an amplifier as opposed to an op amp, you can build to suit a specific gain. you also have access to the internal transistors, so smaller local feedback loops (around 1 stage) can be used rather than 1 big one which is typical with an op amp.