On 22 Sep 2006 04:55:24 -0700, "Telstar Electronics"
wrote:

+++Frank Gilliland wrote:
+++ As far as "matching problems", if you are referring to mismatched gain
+++ in transistor pairs, that only causes harmonics. If the mismatch is
+++ great enough to cause one transistor to run hotter than the other,
+++ that would be due either to component failure or ****-poor quality
+++ control.
+++
+++No, I'm talking about impedance matching problems. On the input is not
+++a big issue... only reducing the available drive... but a mismatch on
+++the output is critical... and causes big problems with excessive
+++transistor heating... leading to premature failure.
+++
+++www.telstar-electronics.com
**************

Mismatches only stress transisitors when they are driven beyond the
manufacturer's reccommended operating points. Like Frank said,
ampheads don't care about specifications. If a transistor is speced
for 100 watts then getting 150 watts out it is better.

james