|
Propeller Head Plaza Technical and scientific discussion of amps, cables and other topics. |
|
|
|
Propeller Head Plaza Technical and scientific discussion of amps, cables and other topics. |
|
In Reply to: Different kinds of problems... posted by Al Sekela on July 16, 2006 at 20:31:01:
As someone else has mentioned, I think, heat sink fins can ring quite a bit causing microphonic effects in power semiconductors. Another area where I think most power transistors tend to have a weakness in audio is nonlinearity near their cutoff region as applied in power amplifiers. This is greatly exacerbated by their typical high transconductance and when operated with the typical low current output stage bias of solid state amplifiers. As a result, from this alone, I think both decently done Class D amplifiers and most tube amplifiers will have a better sounding 'first watt' than the typical 'linear' sand power amp.
I have become quite aware of the contributions of microphonics to the sound of (some) tubes. The 12AX7 is relatively immune, the 6DJ8 and its equivalents relatively susceptible. I designed my triode preamp with all the tubes on a floating subchassis additionally acoustically isolated from the outside world by being totally enclosed in the chassis and by having each tube microphonically damped with a soft wire mesh screen, and with large areas of the chassis panels treated with damping compound.I have also done the above to my DC Coupled OTL with the exceptions that the tubes are exposed to the environment and not on floating subchassis. As a result, microphonics make a negligible to minor contribution to the OTL's sound when it is exposed to SPLs of up to 120db (the highest I could attain with it driving my speakers). In any event, it is considerably cleaner within its power envelope than my Crown K2 Class D amplifier which lacks both heat sinks and linearly biased sand output stages.
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Re: Different kinds of problems... - Tom Dawson 19:55:13 07/18/06 (1)
- Re: Different kinds of problems... - theaudiohobby 06:35:01 07/19/06 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
