Audio Power 833TNT Monoblock Power Amp

Founded in 2009, Audio Power Labs is a newcomer to the audiophile community. Its first—and so far only—product is the 833TNT monoblock power amp, a tour de force that will be hard to surpass.

This amp is named after the its 833C output tubes, which were developed in the 1940s specifically for audio applications and used extensively in AM radio transmitters. To keep the tubes at a safe operating temperature, a microprocessor-controlled liquid-cooling system uses capillary action to circulate liquid from small hot regions to larger radiating areas and back again without the need for pumps.

The class-A amplifier is based on a push-pull configuration, in which each output tube is connected to opposite ends of the output transformer's primary coil. This is said to provide greater amplification with little or no increase in distortion compared with single-ended tube amps, in which one or more tubes are connected to one end of the transformer's primary coil.

It certainly isn't lacking in power. The rated output is 200 watts RMS into 8 or 4Ω, which is enormous for a tube amp. The frequency response is spec'd from 15Hz to 25kHz with a signal-to-noise ratio >85dB and total harmonic distortion <1% across the entire frequency range.

Audio Power Labs made quite a splash at the AXPONA high-end audio show last month. The 833TNT definitely impressed Stereophile's Stephen Mejias, who took the photo above. Combined with an Audio Research LS27 preamp, Musical Fidelity M6CD CD player, and Vandersteen 3A speakers, he thought the system "produced big, robust voices, and had a good sense of musical flow."

So how much would you pay for musical flow? The price of the 833TNT has not yet been firmly established, but it's expected to be in the range of $150,000 to $170,000/pair. Yes, that's a lot of green, but it buys you two of the most powerful—and visually beautiful—tube amps on the market today.

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AudioPowerLabs's picture

Thank you very much for your comments. We try very hard to make the product appeals to both the eyes and the ears.

We designed the product with the 833 tubes because each one of them, depending on the bias and plate voltage, can pump much more than 1000W. We put two of them together in a push-pull configuration and control the output power to merely 200W in order for the amp to sound so effortless even if it is turned up near

AudioPowerLabs's picture

Thank you for writing an article about our product.

I like your honesty about what compelled you to enter the room--very refreshing! Thank you for letting the world know that our amplifier is one of the coolest tube amps around.
You are right about the fan noise from the two prototypes we took to CES. The units we took to Atlanta were much improved. The liquid cooling system helped reduce the need for high speed fans. A little note about the reason why the volume level was so loud, it wasn

uavK.Reid's picture

I went to the AXPONA show last month and one of the first rooms my friend and I went into was the Audio Power Labs room at the Sheraton in Atlanta.

I was Stunned at the size, power and beauty of these tube amps. Really... pictures cannot do justice to seeing these behemoths in person. The tubes are HUGE. The sound coming from the Vandersteens powered by these guys was marvellous. I noticed the scale and pacing of the music. I couldn't put my finger on it but something just sounded right about these amps. It was just easy listening.

Nice job Audio Power Labs...

uavAVTheaterGuy's picture

As I was finishing up the grueling day of high end audio at CES this year, I stumbled upon the Audio Power Labs suite. I can't remember if it was the gorgeous Tubes or the gorgeous promo girls standing out in front but either way I walked into the suite and saw the coolest Tube amp I've ever seen.

The power requirements for these things are so great that they weren't even able to be demo'd because the lower floors were sucking up all the available juice to the top of the Venetian Towers. Later on my friends and I received a call to come back up to the Venetian towers to hear the 833TNT, once APL had aquired a few UPS systems to run these monsters.

While they were some of the most transparent Amps I had ever heard, the volume level required was a little bit high. I say this because at the time of CES, the units were being cooled internally with a series of fans that operated SO LOUD YOU HAD TO CRANK THE AMP TO OVERCOME THE FAN NOISE!!!

Based on this preview, it sounds like a new Water Cooling system has been implemented, to help alleviate the audible noise issue that was definitely a huge PINK ELEPHANT IN THE ROOM.

If APL has fixed the noise issue this amp should be on the short list for any high end audiophile looking for an insanely powerful amplifier with great build quality and MASSIVE TUBES!!!

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