SMPS supplies are rubbish

[knobtwiddler]

(In reality, there should be no measured performance difference between an audio item powered via a well-designed SMPS or linear PSU. Both disciplines have different moles that an OEM has to whack. There is no reason why PSU noise in the audio path itself should ever be above -120dBV at any frequency. If it is, the design is flawed - whether SMPS or linear. Modern high-end SMPSs are really good. Do not confuse them with junk that's designed to power a printer.)

In the world of high power professional power amplifiers, there still exists high premature failure rates in comparison to the Linear way of doing things. After about 500 watts rms, The vast majority of SMPS amplifiers lack the full required power to reproduce the full audio frequency range.

Since the 1990s, The industry standard has been be measure output power in 20 ms burst, Yet this output power cannot even produce a music signal.
Numerous scientific studies have shown a full 500ms burst power is required to reproduce an audio signal, and 3 full seconds for a reproduction of full bass. None of the manufacturers of SMPS power amplifers, have ever been willing to disclose this lack of true power. Recently a few manufacturers have actually made class D amplifiers with Toroidal power supplies, and the result, was that 500ms burst could be easily
achieved at full power.

The Funny part is that Speaker Power, an SMPS manufacturer, disclosed these very facts of SMPS limitations in high power pro audio amplifiers, to show the fact, that their SMPS design, does not have the same limitations of all other SMPS designs. These limitations being, lack of true power over 500 watts, Power cycling, the need for limiting to avoid power cycling and temperature related shutdowns, etc.

To go back to wall wart power supplies, my favorite ones to pick up are the ones that were used in Canon Bubble jet printers. Way back in 1988 I had a Canon Star Writer 80, and when I see the power supplies show up at thrift stores, I grab then right away for my projects. Extremely well built, with high quality UCC caps installed from the factory. 30 years old and they will go another 30 without the need for me to change the capacitor.
Transformers rarely fail.

Would you be kind enough to supply a link or two to back up this data regarding SMPS amps and outputs over 500W? For example, Lab Gruppen make power amps which specify several KW capacity. They use them in stadiums, where an inability to deliver above 500W (a somewhat arbitrary figure?) would be highly apparent. Hypex sell SMPS modules to power their amps. Mr Putzeys knows what he is doing.

NB - I've seen plenty of transformers fail. The classic is one of the primaries, or secondaries, going open-circuit. Every time it's happened I noted that the TF was being used well within its designed spec. We unwound the TFs and found basic manufacturing faults - just like you might have with any item, linear or SMPS. On one occasion the transformer that failed had come from a highly respected maker.