Great sounding Fulltone pedal. The Circuit board uses carbon composition resistors, Polypropylene WIMA .01 capacitors, and a hand- wound "Tuned Core" inductor. The only change from the original '60's Vox design is the addition of a very usable internal "Resonance Control" which is a large durable trimmer, for Bass and gain adjustment, which is easily adjustable by hand without tools and with room to mark your favorite settings.