Krell Amps and Pre-amps

Neither Krell nor Levinson have yet gotten it right enough that I can stand listening to them, although I haven't heard the latest generation stuff yet, and they keep getting closer. Krell has always been unnaturally punchy and technicolor, and Levinson always neutral to the point of sterile and lifeless. And build quality is above average, but not where it counts. My Krell amp was the singularly most unreliable piece of gear I've ever owned, and all the 100 lbs did was to make it a pain in the ass to keep shipping back and forth across the country for repairs. My advice, sure to be pooh-poohed by many: buy Bryston and be happy, it's plenty good enough for HT use and it will never break.

I have always liked PS Audio, they aren't flashy but they do a great job. I haven't heard their recent amps but I have great respect for their P plants. But one comment here: Any amp (or other component) that really needs a P plant is showing you that it doesn't have a good enough power supply section to start with, and this is unfortunately very common (although very good for PS Audio's sales!). In other words, the designer skimped on transformer size/quality and/or power supply filtering, so now you need a separate and expensive unit just to improve on the performance of the original power supply. It's vastly more cost-effective (and space-saving, and energy-saving) to do it right in the first place than it is to have to add an expensive power conditioner. Hence my preference for amps which are designed with high-quality, properly filtered power supplies in the first place, e.g., Ayre. The power supply is perhaps the most important part of a power amp, and it gets way too little attention by most manufacturers, probably mainly because it is also the most expensive part to do right.

For Krell1: I am not trying to trash Krell, they obviously are an expensive and heavy amp and use good-sized transformers. BUT that is not nearly the whole story in power supplies. As I mentioned, Ayre is one of the few companies I am aware of that goes to the trouble and expense of a choke-input power supply (i.e., a giant series inductor nearly as expensive as the transformer itself). This makes a gigantic difference in the quality of the power delivered by the power supply, and Krell and most others don't bother. And my ears tell me that it makes a huge difference in sound quality, on the same order of magnitude as adding a really good power conditioner (as you would expect...).
There are many other factors that come into play as well, including capacitor quality and sizing, rectifier types, and so on. In addition, there are other potential solutions that can deliver excellent results, including the excellent new switch-mode supplies on the Linn Klimax and Rowland 10/12. A good source of info on this is Pass's website www.passlabs.com. I am not saying that any designer can make a great power supply easily or for free, but that it certainly can be done if they are willing to put out the effort, and most (including Krell) haven't bothered to take it to this level. That is why some products benefit so significantly from power conditioners, and others either don't seem to care or, if they have really good power supplies, can actually sound worse with conditioners.