[High_Q]

I learned that tube amps how low dampending than solid stage amps.  When the specs mention dampening, is it mechanical or electrical?  How does that effect sound quality?  I welcome detailed explaination, engineering principles will not fly over my head.

 

[Shike]

Quote:

I learned that tube amps how low dampending than solid stage amps.  When the specs mention dampening, is it mechanical or electrical?  How does that effect sound quality?  I welcome detailed explaination, engineering principles will not fly over my head.

Damping is related to output impedance on amplifiers.  The value of it in regards to headphones is debated, though it's pretty much a desirable attribute for many speaker users (higher being better - lower output impedance).  It basically allows an amp to exhibit better control over dynamic transducers.  Some argue this is bad or signifies too much negative feedback (which others argue negative feedback is a necessity and modern marvel).

 

[xnor]

The output impedance (Zout or Zsource) and the headphone's impedance form a voltage divider. High Zout (= low dampening factor) will cause frequency response variations.
 
Simple example:
A headphone has an impedance of 50 ohms at 1000 Hz and 100 ohms at 100 Hz.
Zsource is also 50 ohms (= high), that results in a damping factor of Zload/Zsource = 1.
 
Signal is 1V, 1000 Hz: the load is 50 + 50 ohms, the headphone will see 0.5V.
Signal is 1V, 100 Hz: the load is 50 + 100 ohms, the headphone will see 0.66V.
Thats a difference of about +2.5 dB at 100 Hz.
(like using a parametric eq with a peak at 100 Hz with +2.5 dB, bandwidth depends on the impedance peak of the headphone)
 
Headphones often just have one broad impedance peak around 100 Hz and rising impedance towards 20 kHz.
Speakers have more peaks, which can be quite narrow and that can be a bigger problem.
 
I've read in an article (blind test with different output impedances) that with speakers a factor of at least 10 is desirable.