ATI AT-6005 Signature 5x300 multi channel amplifier

Note: These pictures have some shadowing from bad lighting...the amplifier is in near perfect condition, I was not able to find any marks but there may be something minor that I missed.

This amplifier was purchased in February of 2015 and has over four years remaining on it's 7-year transferable warranty. List price $6,395. This amplifier was used for about a year before I had to move related to my work...and it has been in its original box ever since.

300 watts X 5 channels. Two Toroidal transformer power supply class A/B amplifier.

It compares very well to the Bryston 4B SST that it replaced...when I moved from HiFi to a 5.1 setup. Very powerful, excellent sound and really takes control.

Please read the Sound & Vision review of this amplifier

- 5 out of 5 for Performance, Ergonomics & Features

- 4 out of 5 for Value

https://www.soundandvision.com/content/ati-at6005-amplifier

Conclusion of the article:

My reference amplifier for a 5.1 system is a John Curl–designed Parasound Halo A 51. I purchased this amp last spring after wanting to own it for more than 10 years, and I consider it to be one of the best amps that money can buy. The highest acclaim I can give the AT6005 is that at no time did I miss my Parasound during my audition of the ATI, which is something I honestly didn’t expect. In fact, if I were in the market for a new amp, the ATI would be at the top of my list, due to its low noise and seemingly endless power output. Highly recommended.

This amp has two power cables. You do not need to do anything special about power outlets, but it gives you flexibility. If you want, you can plug it into two separate outlets and ensure it gets all the power it wants for higher volumes. This amp weighs 116 lbs...it is not messing around. If you are looking at Parasound or NAD...this will blow the doors off of them. This is more like a Krell or Classe without paying for the name. You will love the dynamics, seemingly endless power, low noise and overall musicality of this amplifier. It is simply the best overall value in high-end amplifiers today.

ATI is the house brand for Theta, which you will find on Stereophile's top recommended list.

Here is some info about ATI from their website:

Amplifier Technologies, Inc., the manufacturer of many of the high end’s best amplifiers today introduced this series of amplifiers designed by their president and chief engineer, Morris Kessler. The 6000 signature series amplifiers are available with 2 to 7 channels. This one has 5 channels but could be expanded to 7 if desired (need to send it to the manufacturer for the upgrade).

These amplifiers are special in several ways:

1. These amplifiers are fully balanced, differential amps. The 6000 series uses only a single input stage with dual-differential output stages. The reason: the advantages of balanced designs are retained and noise is reduced by 50%.

2. The design uses current feedback instead of the more common voltage feedback. The reason: current feedback amplifiers are faster with virtually unlimited slew rate and are better able to reproduce today’s best music and film sound.

3. Kessler used Thermaltrak output devices for the 6000 series. Unlike traditional designs where external diodes or transistors attached to the heat sinks track the amplifiers operating conditions and use the details to adjust bias, Thermaltrak devices have the temperature sensing device in the same package as the output transistor. The results: bias is optimized in real-time.

4. The 6000 series use dual DC servos to track and maintain DC offset. The result: DC in the amplifier’s output is reduced to insignificant levels.

5. These amplifiers use a revised PCB layout. They are still modular with the complete amplifier including the power supply parts on a single card, but now the AC components are on one edge of the board and away from the signal input. The result: improved signal-to-noise performance.

6. All of the amplifiers in the series use dual toroidal transformers, dual power switches and dual line cords. The results: the AT6002 is now a complete dual-mono design and the amplifiers with many channels, as in the 7-channel AT6007, can be hooked-up to two independent 20 amp circuits for greater sustained output power than is possible from a single AC circuit. (yes, this amp has two power chords. I had mine connected to two dedicated 20 Amp circuits)

All the amplifiers in the 6000 series are rated at 300 Watts RMS from 20 Hz to 20 kHz with no more that 0.03% THD at 8 ohms with all channels driven and 450 Watts RMS at 4 ohms under the same conditions. Signal-to-noise ratio is typically 128 dB referenced to full output so each amplifier in the series is capable of playing back the full dynamic range available on today’s lossless recordings.

All ATI amplifiers are available in standard (17”) and rack-mount (19”) chassis with domestic (117V) of Export (220 to 240V) chassis and are covered by ATI’s 7-year transferrable warranty.

About Amplifier Technologies

Amplifier Technologies owns the ATI, Audioaccess, B&K, BGW and Theta Digital brands and designs and manufactures state-of-the-art audio components for its own and other brands in its facility in Montebello, CA. Guided by legendary amplifier designer Morris Kessler, ATI offers both performance and value in audio components.

Images: http://www.ati-amp.com/productimages/AT6000_lg.jpg Catalog Sheet: www.ati-amp.com/images/AT6000_catalog.pdf