There really isn't enough information given to respond acurately. What speakers were being driven and what were the other components? Were the differences noted in the same system with just the amps replaced? Was this noticed in the same room? I'm not trying to defend the big boys of the industry but with a blanket comdemnation of such revered names I am suspicious that you may be fishing for controversy. Don't take me wrong, just tell us more and we'll respond. Some of the lesser names in audio do a great job.
high-end vs. ultra high-end amplifiers
It is quite frustrating to know that some amplifiers (Boulder, FM Acoustics, Accuphase) are sounding better than even very expensive ones from the big boys (Mark Levinson, Krell, Bryston, Spectral). I wonder why there is such a difference. Madrigal, Krell, Bryston, Spectral, they all belong to the high-end sector of audio industry and they are claiming they are making the best amplifiers. But I know that this is not true: I've heard amplifiers from Boulder and FM Acoustics and they sound just better than the Madrigals, Krells and so on. Is it because Boulder and FM Acoustics have more know how about amplifier design (I suppose not) or do they use more expensive parts and better circuit topologies? Do they have brighter technicians and designers? There must be an explanation for this phenomenon. It isn't magic! Maybe someone from the audio industry can reply to this thread.