The biggest mistake of my life

My very first product was a phono preamplifier copied inaccurately out of a book. That misstep changed my life and a thousand others. The book was Walter Jung's IC Op Amp Cookbook and in it was a schematic for a phono preamplifier. The schematic called out for one type of IC, a 741 op amp, and I ignored that advice and went with what was readily available, a 709C. Unknown to me at the time I later learned the 741 is a very different sounding device than the 709C. It had been the 709C inside that original prototype phono preamplifier that I had taken to local audiophile Stan Warren's house to audition and it sounded so good he later proposed we start a company called Paul and Stan Audio. It wasn't until nearly half a year later we decided to pay attention to the technical description of the 741:

"The LM74 devices are general-purpose operational amplifiers which feature improved performance over industry standards like the LM709C. It is intended for a wide range of analog applications. The high gain and wide range of operating voltage provide superior performance in integrator, summing amplifier, and general feedback applications."

Aha! we said. We're in for a treat when we replace the 709 with the 741. A free upgrade since the cost of the two ICs was the same. To our great surprise, the 741 sounded dull, lifeless and essentially a total bust. Had I walked into Stan's home with the original circuit based on the recommended 741 he would have never been impressed enough to suggest starting a business together. In fact, based on the 741, the phono preamp didn't sound nearly as good as his Dynaco Pat 4. The biggest mistake of my life set the course of our history and changed the lives of thousands of audiophiles. Sometimes mistakes are the greatest gifts.