The Pioneer A-A 9 is simply one of the best amps Pioneer has ever made. Please be aware that its successor, the A-A 9 MK 2 - is just about the contrary, the example I had tried sounded way to soft and uninspiring.
But the first version sounds partly like a much dearer amplifier: The sounstage is both broad and deep, to a degree that ist unusually authentic for this kind of money. Means that there are many amps up to 5000 $, that can't compete with the Pioneer in this area. The highs have the right mix beetween body and sparkle, tending to crisp. So don't combine with "aggressive" sounding speakers. Mids are neutral, without any added warmth nor coldness. Bass is not very tight but rather full bodied and quite deep, maybe the "weekest" part of the amp (but is still by far on the money). Work, surfaces and buttons quality very good indeed. Remote looks like a joke, but works. Classy design, unreached in the consumer class ! If imaging is the most important part for you, don't look any further. If you find this amp used or unused, give it a try, you won't be disappointed !! Or get the A-A 6 (six) MK 2 (yes Mark two), almost -but not quite- as good.

What a bargain. I love a bargain. Fabulous amplifier with fabulous build quality. Lucid, engaging, very powerful (sounds a lot more than 70 Watts). I only bought it because I got it cheap on EBay (£185) & now it takes pride of place in my system. At £700 the original price it is a bargain. It's goodbye expensive McIntosh and hello Pioneer for me.using with VPI turntable, creek cd, JBL TL260 speakers. No gripes at this money but the remote is very cheap looking ( but you don't listen to the remote) and the built in phono stage is dire especially if using a decent turntable but that's all I can fault. Highly recommended. Rubbish reviews. I will send What hi fi some Johnson ear buds with my compliments. Buy this, enjoy and smile.

My beloved A-A9 is a mark 1. I fell in love with it when I once saw it in photo on a Sunday mag; two years later I bought it as a bargain at AUDIOZONA, (an online Spanish shop, offering many outlet products) for only 499 euros. CRAZY! I expected a decent product but I was shocked discovering from the very start that this is a very serious and a very refined product: independent channels and sparated toroidal transforms. A motorised Alps power wheel. and a tiny and lovely black Alu remote. This amp is GORGEOUS, with a partly curved minimalist front, though not-so-slim and quite heavy. Very good LS connectors. I have quietly compared the sound and performance of this A-A9 amp with three different amps:
(1) A Gryphon Callisto 2200 integrated amp.
(2) A Gryphon Tabu 0ne Hundred vorverstarker/endstuffe combo.
(3) Last but not ldeast, an excellent SONY TA FA50ES integrated.
Sources I used and still own (1) Linn LP12+Lukaschek phono preamp +benz LS mc cartridge (2) NAD s-500 cd (3) Electrocompaniet EMC 1 cd + ECD 1 DAC. (4). Pioneer 06 cd.
Loudspeakers: (1) Dynaudio Confidence 5, (2) ProAc response 1SC, (3) Mission 771.
Cables:
(1) All by Siltech (mainly old stuff, g-3 and g5) .
(2) Straightwire, Sonic Link, Gryphon, Ocos, HMS energia.
My Opinion: Extraordinary amp, refined and musical . More confortable with a the less power demanding ProAc's and Mission 771, but able to work with the routhless Confidence 5 at moderate levels.
I wonder why this amp received mean reviews from What Hi-Fi and other English mags? After two years of moderate use, I can honestly declare that this amp is very good indeed. It compares very well with stuff 2, 3, 4 or 6 times more expensive. Sonically it requires a very good source, top cables and decent LS's (but it prefers good LS's). Supreme bargain, offering refined crystal clear and airy sound with all kind of musics. At his best with acoustic, jazz, chamber classic music or just vocal folk, but not shy with symphonic or rock music. My only complains are: (1) the power connector which has only 2 pins. and (2) I miss a balanced (XLR) input.
Positive but not cucial features are:
There are a Headphones socket. And an USB input that my son finds useful. The phono input is not bad but I used it only once. (instead I connect the Lukaschek or a Trigon phono pre-amp). Different gear produce different flavours and add spice and salt to music, and that's fun. Simply put, this Pioneer A-A9 amp is a joy that produces simply great music. No less. And it's gorgeous too.

An elegant and refined amp. Wicked clarity, transparency and realism.
Reveals all the flaws in bady mastered CDs, which can be a pain, but also reveals the beauty in well produced recordings. Lovely.
Needs to be partnered with a good source and warm speakers.