Is it a myth that SS amps change their sound as they warm up? (1 Viewer)

[3dbinCanada]

I see two fundamental flaws with SS amp warmup and the audible differences people claim they hear. 1) The warmer the transistor becomes, the more thermal or Johnson noise is generated at the junctions of the transistor. It may or may not be audible but the point is that noise generation is increased at the junctions. 2) The warm up time claimed by people is many magnitudes greater than the time required to accurately recall the sound they were hearing when the amp was first powered on.

 

[JohnRice]

I have varying experience. Generally It doesn't seem to take much time for solid state equipment to reach observably peak performance. However, I have an Aragon 4004II, which is a high bias A/B amp, 200 WPC into 8 Ohm biased Class A at 50 watts, that I swear took about an hour to reach optimum. Now I'm using Emotiva XPA-DR amps which are Class H and don't seem to need any noticeable warm-up. I can imagine that maybe 10-15 minutes, just to get up to operating temperature, but doubt much beyond that.

 

[Edwin-S]

I would expect a "warmup" period to affect tube amps more than solid state devices. I've never noticed any difference in sound with my Yamaha receiver regardless of any time taken to warm up; however, people will believe what they want to believe. It is why a placebo medicine actually works on some people.

 

[3dbinCanada]

I would expect a "warmup" period to affect tube amps more than solid state devices. I've never noticed any difference in sound with my Yamaha receiver regardless of any time taken to warm up; however, people will believe what they want to believe. It is why a placebo medicine actually works on some people.

I agree.

 

[jcroy]

In my limited experience with guitar amplifiers, a heavily distorted solid state transistor amplifier sounded the same the moment it is turned on, regardless of what the volume was set to at the power on.

I don't know if there's any way to convince myself of the opposite, for heavily driven transistor guitar amplifiers.

 

[jcroy]

Though in contrast, guitar amplifiers with vacuum tubes in the power amplifier stage does have a huge difference in sound AFTER the tubes are warmed up after a few minutes.

 

[John Dirk]

My answer is "it may depend on the quality of the hardware design." People will always hear what they hear and I wouldn't go down the road of trying to prove or disprove anyone's experience. That said, place any decent SS amp on a test bench and it should remain stable and consistent across it's rated operating parameters. If it doesn't then it's a crap amp by definition.

 

[jcroy]

I would expect a "warmup" period to affect tube amps more than solid state devices. I've never noticed any difference in sound with my Yamaha receiver regardless of any time taken to warm up; however, people will believe what they want to believe. It is why a placebo medicine actually works on some people.

Everyone needs a hobby and "fantasy" to believe in.

 

[Old Dog]

When noticing changes, is it the amp, the speakers or possibly even both I wonder? I have often considered whether speakers also require a warm up. Some speakers have numerous capacitors, my mains 9 a piece for example. My valve amps need around an hour and I would go so far to say that my HT improves somewhat at around 15 minutes too, though the change is nowhere near as pronounced as with the valve amps in the Hifi set up.

 

[JohnRice]

When noticing changes, is it the amp, the speakers or possibly even both I wonder? I have often considered whether speakers also require a warm up. Some speakers have numerous capacitors, my mains 9 a piece for example. My valve amps need around an hour and I would go so far to say that my HT improves somewhat at around 15 minutes too, though the change is nowhere near as pronounced as with the valve amps in the Hifi set up.

When you say valve amps, I’m guessing that’s tube amps.

 

[Old Dog]

Yes, correct John - we call them different over here

 

[JohnRice]

Yes, correct John - we call them different over here

Ah. England?

 

[Old Dog]

Yes indeed - Paradise Island (cough!)

 

[3dbinCanada]

Valve amps require warm up but only long enough for the plate to become hot enough to supply a steady stream of electronics. I would put speaker break in as a myth unless proper dbt listening tests have been conducted and clearly indicate a difference. I would side more on the side of brain break in as the brain is a very powerful and adaptive organ that continues to adapt our perception whether we are aware of it or not.

 

[Old Dog]

I have never tried to do any technical analysis, my views come purely from my 35 years of ownership of the same amps, speakers and turntable (different cartridges and tubes though). I know I can forget any serious listening for the first couple of album sides (stodgy bass and an erratic treble), after about an hour the system really opens up and starts to "sing". Could also be the cartridge, I guess, but CD's don't sound quite right either at the start either.
Before anyone tells me to go to the optician, I got the capacitor count wrong earlier, there are 10 capacitors in each speaker not 9.

 

[MannyE]

I've never noticed any change in SS amps after the initial powerup. YMMV I guess.

 

[Old Dog]

My very first amp was SS and, if I am honest, I can't recall ever thinking the sound changed after switch on. My second amp(s) were valve, that certainly changed the situation. Could be a psychological reason, I guess, why I now believe there are also differences with SS. (I try to keep an open mind).

Having said that, I think we all know when something sounds right. When a new piece of kit is installed in our systems we never know how it is going to sound. Ever had those occasions when you thought things were going to be better after changing something, but they weren't? Or is this a HiFi thing?