Interesting review, thanks for posting it. I think the review might have been a bit too weighted toward measurements (ya think?) and not enough listening impressions but I think the reviewer was obviously mightily impressed with how the amp measured especially into various loads.
I want to make sure that I don't start to become some kind of a whiner or pouting about how interest and enthusiasm seems to be lacking regarding the Perreuax. The initial thread that started all the buzz about this amp a couple months ago spawned some 20,000 views if I am not mistaken and I think had initially generated some real genuine interest. Yes, it was unfortunate that there are some units that have a low level hum and that has made some (a lot maybe) leery to give this amp a try. I'm hoping Perreaux and Audio Advisor will tackle this issue once and for all. It sounds like they are doing everything they can to make it right. One thing to keep in mind is not everybody has experienced this hum and it's only been an issue with very sensitive, low impedance cans. With high Z cans like HD600/650's, and even in my case with CD3000's and Grado's, I hear no hum whatsoever. And, if you read the review posted here the reviewer raved at just how darn quiet this amp is and I agree completely. It's a deadly quiet amp.
I've made it pretty clear my enthusiasm for this amp and believe it is competitive with amplifiers twice it's price or more. Easily. I can't express how good of an amplifier this is. It is by far my favorite amplifier out of all I have owned. There is nothing about it I don't like and I can't say that for all the other amps I have owned which had something here or there that were the means to their end. Bass, midrange, treble, dynamics, balance, tone, detail, space, pace- the Perreaux does most everything seemingly quite well. It has no real glaring mistakes. I'm not suggesting it's a perfect amplifier at all, but it really has no glaring faults, IMO. And further, it seems to pair equally a well with both high and low impedance cans and not favor one or the other.
Like many of us in this hobby I'm enthusaistic and curious about other headamp designs and am curious to explore more but I have to tell you it is going to be hard to imagine getting rid of the Perreaux. I would feel like I'm getting rid of something for no good reason as there is nothing I dislike about it! It may end up being an amp I just have to hang on to and then save up for any new amp I have interest in. I can't express how much I like this amp and encourage others to check it out. It's such a bargain and I think so good and so competitive that it's a shame (to me) that it's not generating more excitement. I'm actually thinking of sending mine off to Hirsch for evaluation and have asked if he would post impressions. He likes the idea and would love to hear it. It seems like at times before anything is fully accepted or taken seriously here at Head-Fi it has to be ran through the staples of the community first. I can't deny that sometimes I too find myself looking to the opinion of certain others before I'll take something more seriously and justifiably so given x-persons incredible experience. Maybe then and only then when something like that happens will this amp find some recognition.