Posted by Thermionic [ 66.233.135.22 ] on April 12, 2004 at 13:36:21:
In Reply to: amp hizzz posted by jim denton on April 06, 2004 at 16:58:13:
Jim, there are several causes of excess hiss. Two of the most notable culprits are old carbon composition plate load resistors that have became noisy with time (in older amps), and faulty SS rectifier diodes. I've seen diodes produce so much white noise that it became louder than the music! What's funny is that they'll still work..........
The noise from old CC plate load resistors is low level, with intermittent fizzing and crackling. The noise from diodes is a constant level.
Thermionic