ION,
Perhaps what DePalma really meant was that transport time in tubes relative to silicone is much much faster.
And I do like his design philosophy, as well as his insight about different gain devices.
Yes, he probably should have said the transport delay in vacuum tubes is significantly less than in transistors by ("x") orders of magnitude. But again this has to be qualified e.g. are we comparing audio grade transistors to audio grade tubes or UHF transistors to UHF tubes. At any rate transport delay in itself is not evil, but may become noxious when negative feedback is used, unless the negative feedback is in the form of local stage degeneration. If it is global NFB, too much of it can produce bad results. This is a complicated issue, both phase, transient and frequency dependent. Having read his historical background, he was very blessed to have the acquaintanceship with the early pioneers of HiFi and tube amp design that he did. Being just a few years younger, I also grew up in that era but did not have the associations except by reading and absorbing the literature of that era and building some of the period designs. His heroes in the field were also mine. I was lucky enough to score the very nice Dynaco A440 output transformer at a surplus store which formed the basis of many of my trial designs back then, but my tube amp construction projects go back to the mid 50's with 4 pin triodes. I also enjoy his philosophy.
« Last Edit: 2013-12-26, 22:07:30 by ION »
---------------------------
"Secrecy, secret societies and secret groups have always been repugnant to a free and open society"......John F Kennedy
|
Author
Topic: Some "New" Observations (Read 290896 times)
