Thanks for the comments, Ackcheng, Gertjan, Eva.
The thing is that, although the supply is specified for 800W output, it has shown a much higher capability.
For example, we have been testing one of our SPS80HV special versions (+/-85V output) with two of our soon-to-come 750W modules, and it drove them quite well, with not too large voltage drop even with hard bass notes. When playing music we measured clipping at around +/-75V with 3.6 ohm speakers, that means around 1.5KW+ peak power consumption. The supply didn't complain at all and remained cool ;-)
The thing is that, although the supply is specified for 800W output, it has shown a much higher capability.
For example, we have been testing one of our SPS80HV special versions (+/-85V output) with two of our soon-to-come 750W modules, and it drove them quite well, with not too large voltage drop even with hard bass notes. When playing music we measured clipping at around +/-75V with 3.6 ohm speakers, that means around 1.5KW+ peak power consumption. The supply didn't complain at all and remained cool ;-)
OK. How does it sound. Mine you that this is compared to the 400W transformer and only one UCD400AD is connected in both cases.
With SPS80, there is not much difference between the high and mid. but the lower end is alot tighter, more punchy and more dynamic.
There is no graininess or harshness. Even though there are some pulses at 170KHz on the oscilloscope, that is way outside the audible frequency and certainly have no ill effect on the sound.
Actually, I have tested UCD output before and I can also see these carrier frequency on the wavefrom. Certainly, most member on this forum can testify that UCD sound very good.
With SPS80, there is not much difference between the high and mid. but the lower end is alot tighter, more punchy and more dynamic.
There is no graininess or harshness. Even though there are some pulses at 170KHz on the oscilloscope, that is way outside the audible frequency and certainly have no ill effect on the sound.
Actually, I have tested UCD output before and I can also see these carrier frequency on the wavefrom. Certainly, most member on this forum can testify that UCD sound very good.
Tests for certification are in progress, for the customers that need them, but as you know these are quite long and expensive.
Basing on our experience, they shouldn't have any problem to pass the certifications as we have tested them near receivers and other sensitive electronic equipment, etc, and even when delivering full power no disturbance was observed, so emissions are very low.
Basing on our experience, they shouldn't have any problem to pass the certifications as we have tested them near receivers and other sensitive electronic equipment, etc, and even when delivering full power no disturbance was observed, so emissions are very low.
Yes, these things sometimes have some funny effects 
However, not all SMPS are made equal, and there a lot of things that affect their performance and EMI behaviour, so design has to be very careful
As you describe it, perhaps that auto-pilot problem was caused by a problem of startup inrush current producing a peak in the system, more than purely EMI/RFI ???
Anyway, talking about airplanes is a different issue, you only have to look at commercial aviation, where you can't even play with your GameBoy during takeoff or landing!
However, not all SMPS are made equal, and there a lot of things that affect their performance and EMI behaviour, so design has to be very careful
As you describe it, perhaps that auto-pilot problem was caused by a problem of startup inrush current producing a peak in the system, more than purely EMI/RFI ???
Anyway, talking about airplanes is a different issue, you only have to look at commercial aviation, where you can't even play with your GameBoy during takeoff or landing!
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