I just purchased THE MONSTER about 2 weeks ago and let me tell yah I can't even express the joy I get when I listen to this baby do its thing.I have it plugged into a BK REF20.When I initally purchased the REF,I had a BK AV5000S2 powering it.The BK 5000was great sounding but was a little bright with dialouge on most DTS movies.Also,when playing BASS hungry tunes the amp was very lean.Enough of that, lets talk about THE MONSTER!As soon as I plugged this bad boy up I noticed the robustness of the dynamics.Also, dialouge was so much more natural and less fatiguing.The bass was definetly there clean tight and with plenty of OOOMPH.THE SOUNDSTAGE was also huge!The first movie I "listened"to was AUSTIN POWERS,and right out of the gate I could hear a tremendous difference between what I was used to hearing from the BK.Finally,I have no regrets about getting rid of the BK,however I do kinda feel bad for the guy who bought my BK off me.NOT! TIP,REF AUDIO is the place to by this BEAST.

I drove to Phoenix and got a chance to listen to this model by accident. I also reviewed the Sherbourn 5/1500 today (see review) and the two don't even compare. I would buy the ATI over the Sherbourn any day of the week. The set up was as follows
Setup
ARCAM Alpha 7 CD
Rotel pre amp
Audioquest ruby interconnects
B&W 603 speakers.

I first put in some Rush, "Xandu" specifically and the depth was there. Very open soundstage, nice mid range, detailed highs. I did notice that the low ends seemed a little sloppy, not sure if it was characteristic of the B&W's or not. I don't think so though, because I also auditioned the Nakamichi PA-5 in the same set up and the lows seemed to tighten up slightly. This amp appears to be of very good build quality. When I looked at the back there is plenty of space to get to the interconnect and binding posts. The Nakamichi, really fell down in this area. It was very difficult to hook up , just from the stand point of getting to the RCA inputs.
I also listened to some Zachary Richard, a song called "Big River". It has a lot of piano and some violin in it, very airy song. This amp performed very well here. When you turned the amp down for soft listening it did not miss a beat, While the music was not as loud, the depth and imaging were still present. The Sherbourn I listened too earlier in the day could not meet the mustard when listened to at low volumes.
I also put in some Tom Petty "Wildflowers". The amp had very detailed highs and a much more forward soundstage with this genre.

All in all I would have to say this is a very good amp. Between this and the Nakamichi, it would be a toss up. I think musical preference will play a big part of the selection between the two.

Power reserves, enough to drive any speaker.

Buzzing

Recently purchased this amp as an upgrade to my receiver(Yamaha 2095) driven system. What a difference! The receiver could not provide the power necessary to drive my hungry Dynaudios. This amp has the sound fidelity I was looking for and the power to drive any 4 ohm speaker I hook up to it. This is my first dedicated power amp so I have a couple of questions. Do power amps such as this require a break-in period like other components I've purchased, i.e., speakers, cables, etc.? And... I'm not experiencing the hum through the speakers that others have, but the amp itself does buss somewhat. Is that normal? The installer I consulted with said it is normal and that the reason behind the buzz is the enormous transformer used by the ATI.

I've had the ATI for about one year. I have been very satisfied with this amp from the get-go. My system consists of the Proceed AVP pre/pro, Rotel RDD-980 CD transport, Marantz DVD-810, and top of the line Cambridge Soundworks speakers. I use the system for CD music, DTS CD surround music, DVD DD movies, and Pro-Logic for VHS tape. I practice critical listening while playing mostly Mozart, but also jazz and new age.
The ATI is a very neutral sounding amp that performs very well musically as well as for home theater. It has plenty of power and runs cool even at high output. It is also very quiet generally but on occassion it does emit a very tolerable hum. I am about to install an "orange" outlet which is a dedicated line and circuit breaker for my system which I hope will eliminate this tendency. The ATI has been very well reviewed by the major magazines and I especially recommend the Audio magazine review for technical details.

i'm posting this review for 2 reasons.a. the ATI 1505 is an ecellent amp at an excellent value, i reccommend it to anyone looking for an amp in the sub $2000 price range without hesitation...
however,
b. i have experienced a problem with the remote trigger using a B&K ref 20, the preamp did not have enough power to trigger the amp remotely, even though the B&K had a 12 volt trigger (what is req. to trigger the amp) it did not have enough "power" to trigger it and required an aftermarket niles step up switch to do so.
THE BIG PROBLEM:
this amp has such enormous transistors and transformers that 10 seconds after shut down, the amps power discharges and makes a high pitched whining sound through all speakers. after 6 discussion with ATI (very helpful) still no solution. DEFINATELY a problem with the design. Tried 3 diffeent 1505's all did the same thing. If you experience the same problem please post.. I'm all ears.

I've been using the ATI 1505 for about 3-4 months now. I'm using a Parasound PSP1500THX pre-amp (along with the ATI) to power a Martin Logan HT (Sequel II's front/Aerius rears/Logos center -- the minimum impedance on these is about 1.5 Ohms @20Khz, the average is 4-6 Ohms).
This amp is everything I expected: clean, natural power and *massive* amounts of it.

The unit itself is a bit bulky (~80 lbs) due to its huge power supply. The
front panel has leds for each channel that light when the amp reaches max power.The overall build is high quality and the unit is SOLID. The gold plated binding posts are "touch proof" and accept bare wire, banana plugs, and spade
connections. Another great thing is that this amp is QUIET-- NO HUM even
if you put your ear right up against it.

After watching literally hours action movies at THX levels (85-90 db)
this amp wasn't even really warmed up! My pre-amp was *warmer* than the ATI!
(the ATI has 425 sq in of internal heat sink per channel)

Also, all ATI amps come with a 7 year parts and labor warranty (that's somehtingto think about--most come with 2-3 years max). Best of all, it lists for $1695
(I think mine was about $100 cheaper).

There are other reviews by Home Theater, AV Shopper, and Audio Adventure at ATI's home page (http://www.ati-amp.com). I bought mine from ECS
(http://www.ecsaudio.com), or you can buy direct from ATI.

-alan

I have owned the ATI 1505 for approximately 16 months. I paid $1400.00 for it brand new from a custom install dealer, (ATI approved). Prior to buying the ATI I was using a Yamaha RXV 590 reciever and was disappointed with out put. Because the Yamaha has pre-amp outs I decided to go amp shopping. I looked at B&K (clean but lower in power), Yamaha and Sony (YUK!), Kenwood (so so) Acurus (great), Denon (good), Classe (to exspensive)and Parasound (good) but out of the 5 good to exspensive the ATI was the one.In the past 16 months I have never been able to make the amp clip! And I do put it to the test. But since that time I have replaced the aging Yamaha with the B&K Reference 20 pre-amp/ Dolby Digital 5.1 and DTS. WOW! My system is getting closer. This amp has really come alive. The stereo imagaing is outragously wide.
I know added a sub woofer (3) days ago(Velodyne CT150) nice.
If you want a back breaking (73pounder) amp that won't give up no matter whether you throw DTS, dolby digital, or just plain stereo (Jazz, Rock or Classical) this is the amp for you. But make sure that you use good interconnect cables to get the most out of this baby.

O.K so I actually haven't listened to it, but I need to.I have been looking and this seems fairly nice from all the good reviews. So the question is, where do I get one for the best price. The ATI 1505 that is.
A definite 5 star for the good people who have been kind enough to review.
Thanks and let me know. E.T.

After having lived with this amp for a month, I still couldn't be more satisfied. I did end up trashing the infinity's, and am now running PSB 500's for my LR fronts, center is a Dunlavy SC-1, and rears are Niles OS-10's (let's not even get started debating on dipoles vs. direct). Soundstaging is great in stereo, and L-R or Front-Back pans (and vice versa) are clear and coherent without any drops. Obviously, this has a lot to do with the speakers, and the preamp (Marantz AV550), but I didn't notice the seamless Front-Back/Back-Front effect in home theater before now. I now feel truly immersed in the picture.
One side note though, unless you're running DB25 out from your pre to the DB25 in on the ATI, the remote-on function does not work...oh well.

I do not intend to be polemic, but for those who make big claims on multichannelpower amplifiers such as the ATI1505, ADCOM GFA-7000, CARVER 705, and the like from CINEPRO, as well as for those who want to purchase a new multichannel power amplifier, my advise is short and simple: "Do not make any claims, and DO NOT purchase any multichannel power amplifier, until you have tried the CITATION 7.1 power amplifier (150W x 4 channel)".

Granted, CITATION dealers are scarce (CITATION brand is manufactured by MADRIGAL
AUDIO LABORATORIES), ads and reviews on CITATION equipment are rare, and the CITATION 7.1 is not unexpensive ($2,850), but this is a monster (MONSTER!) piece of equipment in any regard: definition, power, finesse, built quality, beauty, etc.(let aside weight: nearly 80 pounds). We are talking KRELL-league here! We are talking nearly orgasmic experience here!

My humble advise: Give CITATION 7.1 4-channel power amplifier a try (for both Home Theater & Music). Your bases are not covered until you have listened to this magnificent piece of equipment.

José Vicente Gomez