Audio Power 833TNT Monoblock Power Amp
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 powerfuland visually beautifultube amps on the market today.