Thread: Conrad Johnson ART vacuum tube Power Amplifiers

The limited edition ART Amplifier is designed to be a reference amplifier for the use of industry professionals as well as dedicated audiophiles. Like its companion GAT Preamplifier, the ART Amplifier will be offered in an edition of just 250 units (125 pairs) to be sold through selected conrad-johnson dealers and distributors. Those who do not need the prodigious 275 watt power delivered by the mighty ART mono-blocks will want to consider the ARTsa Stereo Amplifier. Nearly identical cosmetically (one more tube in the front), it is exactly an ART amplifier divided into two channels, each producing a solid 140 watts. At conrad-johnson, our approach to circuit design is predicated on the principle that the surest path to both state-of-the-art musicality and exceptional reliability is simple circuits constructed of the finest available parts. These ART amplifiers exemplify this basic principle. The audio circuit has just three elements, each as simple as possible, and each essential to the operation of the amplifier. A voltage gain amplifier (a single triode) is direct-coupled to a cathode coupled phase inverter (each phase handled by a single triode), which in turn drives the output stage. For the ART mono-blocks, four pairs of KT120 output tubes, chosen for their musical accuracy, high power, and reliability, endow this amplifier with a muscular 275 watt output rating. For the ARTsa, two pairs of KT120 output tubes in each channel produce 140 watts of power per channel. A small amount (about 12 dB) of loop negative feedback reduces distortion and achieves a sufficiently high damping factor to control the reactive load typically presented by high-performance loudspeaker systems. To assure continued peak performance, the owner need only make a simple bias adjustment when new tubes are installed. Built in LED bias indicators allow the user to make this adjustment using only the supplied screwdriver. Separate, low impedance, discrete dc power supply regulators are provided for the input and phase-inverter stages, thoroughly isolating these stages from the power demands of the output stage. These power supplies are designed to maintain a rock solid supply at all audio frequencies. Component parts contribute importantly to the sonic performance of any circuit design. The ART amplifiers maintain the exacting quality standards for which conrad-johnson is internationally known. Resistors are precision laser-trimmed metal foil types. Coupling capacitors are the new Teflon CJD caps, while the power supplies use large value polypropylene capacitors in parallel with CJD Teflons. There are no electrolytic capacitors in the audio circuits or in the related power supplies. Proprietary wide-bandwidth output transformers contribute to excellent high frequency performance. Even the machined gold plated OFC connectors and the internal wiring have been carefully selected for optimal sonic performance. Attention to every detail enable us to extract the full potential from our circuit designs and ensures that our products will perform to this potential for years to come. The ART and ARTsa amplifiers are built without compromise to achieve a new standard in musical performance, and they are built to last. Visit a conrad-johnson dealer soon to hear for yourself just how true to the music an amplifier can be.

Specifications: Power: ART Amplifier - 275 watts from 30 Hz to 15 KHz at no more than .5 % THD or IMD into 4 ohms (also available connected for 8 or 16 ohm loads) ARTsa Amplifier – 140 watts per channel from 30 Hz to 15 KHz at no more than 1.5 % THD or IMD, both channels driven into 4 ohms (also available connected for 8 or 16 ohm loads) Sensitivity: 1.8V to rated power Frequency Response (at 10 watts): 20 Hz to 20 kHz, +/- .25 dB Frequency Response (at 10 watts): 20 Hz to 20 kHz, +/- .25 dB Hum and Noise: 108 dB below rated power Input Impedance: 100 kOhms Tube Complement: ART - 1 x M8080, 1 x 6N30P, 8 x KT120 ARTsa – 1 x 6189, 2 x 6N30P, 8 x KT120 Dimensions: 18.75D x 19W x 7.13H inches Weight: ART - 83 Lbs. ARTsa – 82 Lbs.

CES 2013: Conrad-Johnson | Confessions of a Part-Time Audiophile

Conrad-Johnson GAT Preamp and ART Monoblock Power Amp | The Absolute Sound

Thanks for the links Doug. Very nice.

Absolutely beautiful stuff. Maybe not everyone's cup of tea, but just look at that...

Sweet dreams ....

I've wanted a pair for a long time.

Joe! Just noticed your sig... Do you have a new GAT and ART monos already? Assuming you do... I'm patiently awaiting your report. Also I'm almost afraid to ask how much heat those monos radiate!

Originally Posted by Rayooo

Joe! Just noticed your sig... Do you have a new GAT and ART monos already? Assuming you do... I'm patiently awaiting your report. Also I'm almost afraid to ask how much heat those monos radiate!

I believe this would be Joe's second stint with the GAT, which, to me, means it's one hell of a pre.

Originally Posted by Rayooo

Joe! Just noticed your sig... Do you have a new GAT and ART monos already? Assuming you do... I'm patiently awaiting your report. Also I'm almost afraid to ask how much heat those monos radiate!

Hopefully late next week or the following week.

Originally Posted by SFete

I believe this would be Joe's second stint with the GAT, which, to me, means it's one hell of a pre.

You are correct. Some pieces just stick in your head.

Originally Posted by joeinid

Hopefully late next week or the following week.

Wait a minute. These came out roughy this time two years ago. CJ only made 250 each of these and you already found some?!!!

You rule the audio world!

Number #251

Originally Posted by joeinid

Number #251

That doesn't compute


Fuggedaboutit

Nice score Joe!

Originally Posted by dlb2

That doesn't compute


Fuggedaboutit

Nice score Joe!

I don't think they ran out. I'll know soon enough what numbers.

Mine (GAT) is 074, Joe remembers that number.

Joe, once I get your blessing on the ARTs, I'm going to have a real hard time not picking up a pair!

Originally Posted by Rayooo

Mine (GAT) is 074, Joe remembers that number.

Joe, once I get your blessing on the ARTs, I'm going to have a real hard time not picking up a pair!

I never should have given that one up Ray. It was hand picked by its creator and is a special unit. I just hope the one I get is just as good. I really think the ART monos will be outstanding. There is no denying that there is something special about CJ gear. Plus one more thing. Synergy is real and the GAT/ART combo will have it in spades.

If I live to be 100 years old, someone will be going through my hifi gear and be wondering what they should do with this strange thing with the gold face and tubes that says GAT on the front panel when It's plugged in.

and...maybe there'll be a couple mono amps that look strikingly similar.

Originally Posted by Rayooo

If I live to be 100 years old, someone will be going through my hifi gear and be wondering what they should do with this strange thing with the gold face and tubes that says GAT on the front panel when It's plugged in.

and...maybe there'll be a couple mono amps that look strikingly similar.

Stay thirsty my friend.

Originally Posted by Rayooo

If I live to be 100 years old, someone will be going through my hifi gear and be wondering what they should do with this strange thing with the gold face and tubes that says GAT on the front panel when It's plugged in.

and...maybe there'll be a couple mono amps that look strikingly similar.

I think they are a defining moment in time and should be considered a lifetime piece for sure. You are a lucky man to have one.

....ah, crap.. here I go considering violating my own rule about driving 20.7s with a tube power amp. I'm sure it's been done, right?

At least the ART having it's std. power output listed into 4 ohms is encouraging. The JC-1s manage a vise-like grip on the 20.7s which is wonderful to behold.
I'm beginning to get that queasy feeling already that a transformer out tube-amp just won't have the low-end control as a big SS amp.

Oh great - one more thing to confuse me with!