Tubes vs. transistors & quantization distortion After reading an article in a 1987 issue of Discover magazine about the popularity of tube amps I decided to try building one using TV tubes and then later, HiFi tubes (and still later, I collected some tube monoblocks and stereo amps I found in antique and thrift stores). Before this I was experimenting with solid state audio circuits and tubes seemed to give me what I was looking for. One day while pondering the tube vs. transistor sound mystery I tried visualizing the inner workings of tubes and transistors. With tubes, amplification seems to take place (almost) entirely in a vacuum and classical electromagnetic theory seems adequate to explain most of it. With transistors you basically have to start with quantum mechanics to explain how they work. An idea came to me, could it be possible that solid state electronics produce a kind of quantization or quantizing error distortion because of their quantum mechanical nature? It seemed to me solid state sound had an unnatural characteristic similar to the digital sound from CDs. I wrote to Ed Dell in 1990, Amateur Audio Publications, Inc. editor, about this idea and he published my letter, in Glass Audio magazine and he wrote back and told me about some publications by Malcolm Hawksford about some work on “the molecular and atomic activity within solid state devices as well as work on quantizing problems”. I looked through some books in the library about transistors and didn’t find much that would lead me to the answer. I did find something about traps in semiconductors and a graph that had steps in the audio region, but don’t know if that’s related or not. After finding Ed Dell’s 1990 letter recently while looking through some old papers, I decided to look on the internet to see if there are any articles by Hawksford available. I found a site with a collection of them and one article of his which discusses quantizing distortion in transistors. Looking through the equations, it appears to me that it doesn’t have anything directly related to quantum mechanics in them. The website is http://www.essex.ac.uk/csee/research/audio_lab/malcolms_publications.html and the article I read is J7 FUZZY DISTORTION IN ANALOG AMPLIFIERS: A LIMIT TO INFORMATION TRANSMISSION?, M.O.J. Hawksford, JAES, vol.31, no.10, pp.745-754, October 1983 http://www.essex.ac.uk/csee/research/audio_lab/malcolmspubdocs/J7 Fuzzy distortion.pdf I’m wondering if this effect is seen in tubes or not. If it is, maybe it’s a lot less compared to transistors based on their subjective sound qualities. Could quantizing distortion be the main cause of the difference we hear in tubes and solid state circuits? Maybe its only seen/heard in solid state and not in tubes to any significant degree if at all.