Home > Consumer Reviews > Onkyo A-9555 Integrated Digital Stereo Amplifier (Black)

After years of getting mixed result from multi-function receivers, I have decided to try a dedicated stereo amp to see if the music really sounds better. And it turns out that it does. There are many brands out there but the real choice (testing the equipment) is quite limited. Since my favorite mid price brand (Harman Kardon) does not offer much in the integrated amp area, the focus shifted to another popular and easily available name -Onkyo. The A-9555 got pretty good marks, but there was very little information on its A-5VL successor available in September 2009. Thanks to generous return policy I got both models and tested them with two sets of headphones - Denon AHD 2000 and Sennheiser HD 800.
Staring with the newer A-5VL model, the moment I turned up the volume knob there was the "WOW" factor. I have never before experienced that excellent sound quality from a mid priced amp and instantly felt this is something to hold on to. However, after a while I have noticed that that the sound does have that sharp digital quality different from the "tube-like" softness and warmth I was looking for and found in its predecessor.
Thus, the A-9555 is a real winner here - sonically more realistic, with a wider sound stage and twice the (Watt) power coming at a lower price tag. I can honestly recommend this amp to anyone looking to boost the CD sound without spending thousands of your hard earned dollars.
Both receivers have very good headphone output, but they really lack quality phono input. A Vinyl record played with Technics 1200MK2 sounded no different than a CD.

Apparently Onkyo has limited quality control. The unit arrived DOA (Remote unresponsive, all source selector lights lit up except for the Tuner & MD lights. No other lights would light up).

On a side note, for those planning on using the phono pre-amp, it does not work with Moving Coil cartridges.

***UPDATED***
I packed up the defective unit and sent it back to Amazon. While packing up the defective unit I noticed that something was loose inside. Perhaps the unit was damaged in shipping and it had nothing to do with Onkyo's quality control. I don't know.

What I do know is that my replacement unit works and the sound is absolutely stunning. The Pure Audio button is is a very welcome feature as it allows me to hear the sound from my records the way it was intended. For reference I have this hooked up to a Rega P3-24 turntable with a high output moving coil cartridge. That's right, it does work with my high output moving coil cartridge. Your mileage may vary.

I agree that this is a good amplifier. However, it lacks a balance control knob, making it is impossible to adjust the relative loudness of the left and right channels. I consider this to be a major design flaw.

See my full review posted at www.audioasylum.com for the complete descrition. Ths amp in my 20k system really shined. Onkyo is to be commended for building an amplifier of this qualit at this price level. I said it in my review. A new classic iis born.

This was to possible replace either my Pioneer Elite A91D or my Pioneer Reference A717 integrated amp in some casual listening systems I have. I kind of bought it on a whim without doing any research on it.
First blush casual listening I thought the Onkyo A-9555 had some potential, seemed warm and inviting sounding, but that all changed with more listening time. After doing some critical listening with widely varied sources over time I have to do an about face. First impressions are not what they seem with this amp.

Quick summary: Joni Mitchell, Court and Spark for vocals. Vocals sound nice, but things seem a bit soft. Time to get more demanding on the amp.

Holst The Planets for classical. Again sounds smooth at times, but when there's powerful passages, things go limp, the power of the orchestra actually seems to collapse in on itself. An odd thing to say the least and VERY unacceptable for any listening situation.

Some bass demanding pop stuff, Chumbawamba Tubthumping, NOW we really find the pig with lipstick on showing up. The guts just are not there. This tune can easily make the whole house shake with either Pioneer amp, it isn't happening with this thing. The speakers are willing but the amp is seriously straining.

Some pretty demanding jazz fusion, Love Devotion Surrender W/ John McLaughlin & Santana, the tune Love Supreme, where's the beef? Just does not pin me in my seat like it should. John's guitar loses that immediate in your face quality that I love about this recording.

Rock, Robin Trower, remastered Bridge Of Sighs. Same story, the amp just doesn't have any beef when pushed above casual listening levels, everything seems to collapse in on itself and gets compressed.

The final nail in the coffin, some of my own tapes, these were loose off the cuff jams that actually sound pretty good, there's a lot of quiet passages as well as full tilt rock blues....a Fender Twin with a wailing Gibson Explorer, a Fender bass guitar through a Peavy 2X15" amp, and a small drum kit, very raw, simple, clean uncompressed recordings. Here's where the amp really fell on its face. The Pioneer Elite amps play my stuff and never run out of steam. I always get a bit of a grin listening to my own brand of sonic noise. But with this amp it sounded like someone did too much compression on the recordings and they actually sounded harsher than normal. I literally had to turn the tapes off, I couldn't stand what I was hearing.

To verify I drug out another similar power rated integrated amp I had laying around, a Sansui AUX 911DG, which I always felt was a bit smoother sounding than the Pioneers, but didn't quite have the same amount of beef. It got moth balled due to an occasionally noisy volume pot.

The Sansui sounded easily just as smooth as the Onkyo on the same passages when the Onkyo was actually managing to sound smooth, but the Sansui didn't fall flat on its face when things got demanding like the Onkyo does.

My opinion, I now think the high end is rolled off on this amp giving a first impression of tube like warmth and smoothness. Fact is though the air and extreme top end is sorely lacking on this amp, the edge of breath on vocals, the tail of reverb, cymbals, all lose that top end making them sound more lifeless.

First impression may be one of "oh this amp sounds musical, smooth" BUT....When asked to deliver the goods it's true colors show. Mind you all of these amps I'm comparing it to are "rated" at around 85 -100 watts per channel, close enough to being the same power for all intents. But this class D amp just can't run with a class A/B of similar rating when pushed. It might be fine for quite, low demanding music and background listening, but for any attempt at serious listening it falls far too short.


For $399 it's a nice little amp, list $799, forget it. I'll hang on to my old Pioneers until they smoke out. This one goes into the garage system or on E bay.

UPDATE 06/29/09.

Well after a few months of living with this I stand even FIRMER by my original review. Time has not changed anything and I have now pulled the amp from the system it was in and relegated it to my garage system, which is where it belongs. A FAR CRY from a great amp for sure.