สำหรับ Spec ของรุ่นนี้จะแตกต่างจากรุ่น WA7 ที่เพิ่มตัว in put ช่องดิจิตอลแบบ optical เข้ามา และยังเพิ่มรองรับไฟล์เพลงคุณภาพ Hi-Res ขนาด 32-Bit, 192K ครับ สำหรับท่านที่ใช้ Source ที่มี Line Out แบบ Optical สามารถใช้งานได้ทันทีครับ
Woo Audio WA7d Fireflies Duo
Pure Class-A tube headphone amplifier with 32-Bit, 192K USB Digital-to-Analog Converter
Dual digital inputs with USB and Optical
The new WA7tp (left) is a vacuum tube external linear power supply utilizing two 12AU7 tubes as rectifiers.
Building on the foundation of our multi-award winning WA7 Fireflies. The new WA7d adds optical (Toslink) digital input for expanded sources compatibility. Optical output is commonly found on Digital Audio players, CD/DVD players, XBOX, PS3, PS4 and on some TVs. The addition of optical input allows the WA7d to operate as a DAC for those devices, utilizing the advanced internal 32 bit digital to analog converter (DAC) for an improved sound.
WA7d Fireflies retains the same high-performance TI PCM5102A DAC chip and amplifier section as the WA7. The asynchronous USB 2.0 DAC is capable of decoding up to 32-bit/192kHz sample rates. A pair of 6C45 triode tubes acts as both driver and power in a single-ended Class-A design with transformer coupled outputs. An unbalanced RCA input allows for analog sources such as a turntable (with Phono stage) to be used with the WA7d Fireflies. There are no semiconductors used in the entire amplification path.
To maintain a small footprint and silent operation, we housed the custom built toroidal transformer in an external chassis. Every part was carefully chosen or custom built to deliver the best in audio performance. No matter which model you choose, WA7 or WA7d Fireflies will deliver many years of musical pleasure.
The Firflies is powerful enough to drive any dynamic headphones, including the Audeze LCD-2/LCD-3, HifiMan HE5/6, Sennheiser HD800, Beyerdynamic T1, and Grado GS1000/PS1000, and more. Its dedicated mini phone jack is a true support for any IEMs. The large volume control ensures a smooth operation and precision.
6C45 is a "super" tube as it has a 50x gain and a large output. These attributes allow the Fireflies to have a incredibly clean and simple design.
WA7d Fireflies with a Windows 8 Pro tablet.
Hi-Z position is for high impedance headphone output while LO-Z is for low impedance. The RCA/USB/D-A selector is a custom made 3-position slide switch for Optical input, USB digital input, and RCA analog input
The high performance linear external power supply is designed to work in a long hours operation. It is low noise and low heat.
Available in Black and Silver
We chose this commonly available tube for the convenience of allowing the user to tubes swap among other brands available for a personalized, tailored sound signature.
WA7tp (left) and WA7 (right), Audeze LCD-X on the far side.
Tubes glow in the dark.
Anodized finish available in Silver and Black.
All-tube design (not hybrid)
Class-A, Single-ended Triode transformer-coupled
Improved analog circuit
6C45 x2 driver/power tubes, 12AU7 x2 rectifier tubes for WA7tp tube power supply upgrade
Teflon tube sockets
ESS SABRE Reference DAC (ES9018K2M)
XMOS xCORE-AUDIO asynchronous USB compatible with Mac, PC, Android and iOS devices*
Headphones impedance : 8-600 Ohms
Input impedance: 100 Kilo-Ohms
Hi-res audio playback up to 24-bit/384kHz
Inputs: 1 high-retention USB (Type-B) input, 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
Power consumption: 25W max
Mains supply: 100-120V, 220-240V, 50/60Hz, user selectable
Finish: Anodized aluminum
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