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Does a Solid State amp sound better when warm?

#24
Going from the dogsled to the igloo let them warm up 5 minutes.
Going from hot to cold is worst. The hot air holds more moisture, you put it in cold and the water condenses out making droplets of water. Mixed with dust these can conduct electricity. So always play hot, hot, hot
Good amps have no problem either way.
 
#28
chucko58 said:
With all due respect to the folks who actually know their electronics, I could believe that crossover distortion would change from just-powered-on cold to fully warmed up. I have to think it's a small effect in a well designed power amp though.
Click to expand...

This seems possible, but like you say, it should be minimal in a well designed amp.

And it raises an interesting question. Since Class-D amps are constantly "crossing over," does it mean that they don't suffer from crossover distortion?

Also, your speakers definitely change their characteristics when warm, as do your ears.
 
#34
Bob Lee (QSC) said:
Bias circuits in well-designed SS amps have temperature compensation.
Click to expand...
Bob how normal is it for a s.s poweramp to distort from bias problems in only one channel ?
What if it reoccures in that same channel again every 2 years,why is this ?
Does it mean that the unstable side will distort from not being biased properly ?
How often does this happen to s.s poweramps & how can it be prevented or atleast helped to be slowed ?
Class H amp in question but any 2 channel poweramp really.
 
#38
Temperature compensated bias will lag behind true internal transistor temps since the tracking device is not located on the internal transistor die and this will be seen on test equipment and possibly be heard if the lag is too great. Most well designed solidstate power amps, from a reliability standpoint, also have current limiting circuits that can really kick in when the amp is approaching thermal shutdown temperatures to slow down the temp rise curve and prevent thermal runaway which gives the shutdown circuit time to work. This will change the sound mainly due to reduced headroom and if properly designed will introduce minimum distortion.

Class D amps will always have some crossover distortion due to the opposite polarity output devices not being able to be on at the same time and there will always be some very small amount of time both outputs are off before the zero crossing point. If both are on at the same time it lets the smoke out although this may have changed since I've not kept up for some years.

IMO the answer to the OP's ??? is that there is a designed temperature range where any amp sounds the best. Solidstate should be run as cool as possible but not so cold as to interfere with temp tracking circuits. There's also an ideal temp for tubes. The heaters and cathodes have to be at a high enough temperature to freely emit electrons. If the temp of a tube is reduced enough, it will not conduct. One of the "brown sound" tube guitar amp tricks was to lower the line voltage fed to the power transformer. A 10% or 15% reduction there would reduce all the supply voltages by the same percentage which wouldn't have a great effect on the power output of the amp but would have a noticeable effect on heater temperatures and affect the ability of the cathode to emit electrons. The bias should be adjusted for reliability and less of the nasty sounding crossover distortion but to some it was part of "the sound".

If I've made some bad points please chime in. A memory is a terrible thing to waste.

mech
 

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