We had learned that despite the expert's opinions, and the measurements that supported those opinions, "identical" functional amplification blocks could sound dramatically different.
The world had been flipped on its head for us and, as time went by, we began to extrapolate new ideas based on this knowledge.
If one looks at the internal schematic of an IC op amp (which all the companies making them readily published), the differences were dramatic. The 709C was at its core, a current sourced diff pair feeding a gain stage and then out to the buffers. The 741 was a much more complicated and higher open loop gain device that used lots of open loop gain and, we later found, a slew rate that was embarrassingly slow.
Here's the schematic of the 709C
Now, compare that with the 741
Whether this makes any sense to you or not isn't the point of the story. The essence of what we learned is that the internal circuitry of each device determined its performance (duh). And to not look at the IC chip as a functional block, but rather as a convenient package for a discrete circuit.
In other words, if we could figure out the difference between these functional blocks and what made them sound so dramatically different, then we could skip the IC idea and make our own discrete version that could capitalize on the difference and expand it.
So, we started with the simplest of how a discrete op amp works (diff pair, gain stage, output stage) and began tinkering and listening to figure out what mattered and what didn't.
The result was not only the next generation of preamps from our company—all discrete and without any ICs at all—but would set the course for the next 50 years. Our ability to control the parameters of what mattered sonically was the key.
*In the ensuing 50 year period, IC op amps have finally caught up to discretes and in many cases sonically stomp our best attempts at discretes. But, that's another story.
