|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
209.97.232.21
In Reply to: Transistors' dirty little secret... posted by Al Sekela on April 10, 2007 at 12:51:40:
<< Tubes don't have this particular problem, but all of them are microphonic to some extent. >>Plus most of them use steel pins and steel internal parts and are prone to hysteresis distortion from the magnetic fields.
Not to mention the fact that they are wearing out every time you turn them on...
Follow Ups:
Well, it’s a good thing then that being a high voltage device, the currents are exceedingly low and so are the magnetic fields produced internally. A tube like a 6SN7 can produce VERY low distortion with a spectrum that is low order. Hysteresys distortion is a problem in output transformers associated with Tubes however and they are to varying degrees microphonic.
For that the tap test will tell.Yes they wear out a little bit each time but finding either at a garage sale or attic, the odds of a 20 year old solid state amplifier working are smaller than that of a 30 or 40 year old tube amp working. Plastic transistors are not “air tight” like Pyrex and frit glass, they usually get leaky and fail. Tubes can leak too when the repeated thermal expansion causes micro fractures around the frit and pins.
SS and Tubes are entirely different ways of doing the job, each has totally different strengths and weaknesses from an engineering standpoint.As for the “memory”, the thermal shift is real, I have no idea if you can hear it.
On the other hand, for a Voltage amplifier the cascade approach already minimizes the collector swing on the onput, making the Voltage between the two transistors larger would further reduce the pdis swing and increased the avg pdis.
Heat them inputs up with static bias
Best,
Tom Danley
So right. A tube amp is simple for anyone to fix. It's easier to replace six or eight tubes than it is to find out which of the 40 or 50 transistors inside has failed.
Provided the tubes are good, they can last much longer than a ss amp. Replace the handful of electrolytic caps. every ten or fifteen years and you are all set for another decade. Or you can do the same with a ss amp, although replacing 40 electrolytics in it might be a hassle...
I literally spent 30 years buying one ss amp after another trying to find one that had the sound I wanted. None did. Most of them sounded the same to me, regardless of how much I spent.
"None did. Most of them sounded the same to me, regardless of how much I spent.
"
!
And so are most of us......... :)
| ||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: