The WOO Audio WA7 "Fireflies" Amp/DAC is a combination of high performance vacuum tube headphone amplifier with a built-in USB Digital-to-Analog Converter.
It is a pure tube design, utilizing 6C45 tubes in a class-A, single-ended topology, with transformer coupled outputs. There are no semi-conductors used in the entire signal path. The D-A converter is designed to be capable of up to 32-bit/192k sampling rates. This maintains pure data integrity, which is transmitted via standard high speed USB 2.0 interface operating in asynchronous mode.
The high quality construction features include a pair of Nickel Alloy core output transformers, all-aluminum chassis with no screws visible from any viewing angles, a linear external power supply for amplification circuitries, a custom built toroidal power transformer, and multi-layer military grade PCBs.
The dedicated port for in-ear-monitors carries a full range of volume controls ensuring minimal noise. Despite its incredibly compact size, "Fireflies" is a power-house with the capacity to drive almost any demanding audiophile headphones. To accommodate different system setup needs, "Fireflies" can also be used as a stand-alone D-A Converter.
Single-ended, class-A, transformers output
Linear external high-performance power supply
Two 6C45 driver/power tubes
Headphones impedance: 8-600 Ohms
Input impedance: 100 Kilo-Ohms
Sampling rate: up to 32-Bit, 192kHz
Inputs: 1 Asynchronous USB2.0, 1 RCA
Outputs: 1 1/4" and 1 1/8" headphone outputs, 1 RCA (same connector as the input)
Max output: approx 1 watt @ 32 ohms
Frequency response: 11Hz to 27kHz, +/-0.5dB
Mains supply: 100-120V, 220-240V, 50/60Hz, user selectable
Finish: Anodized aluminium
DC cord length: 4.25 ft or 1.3 m
Dimension: AMP: 4.8" L x 4.8" W x 5.1" H with glass
PSU: 7.5" L x 3.5" W x 2.2" H
Weight: AMP - 5.3 lbs / 2.4kg, Glass - 3.3 lbs / 1.5kg