all of my parts that I don't have come from digi-key or some other supplier. I probably have a few billion transistors, resistors, diodes and 555 timers, and capacitors ranging from 1picofarad to over 1000microfarads to name less than a quarter of my supply, I need to check to see if all of my scopes work, been awhile. I only order parts that I know I don't have or haven't seen in any of my inventory.