Woo Audio WA7 Fireflies Tube Headphone Amplifier with DAC - Generation 3 - Black

A Tube DAC/Amp That's Now a True One-Box System

The Woo Audio WA7 Fireflies Generation 3 is a tube headphone amplifier and DAC in one compact glass-topped enclosure. Two 5963/12AU7 tubes handle amplification, running in a self-biasing circuit and seated in premium PTFE sockets. Woo Audio designed those sockets so the tubes stay user-replaceable and upgradeable down the road.

This third generation adds a built-in linear power supply, replacing the external supply earlier WA7 models relied on. That change turns the WA7 into a genuine one-box solution, with nothing extra to place on your desk or shelf.

Generation 3 also introduces preamplifier outputs, letting the WA7 drive powered speakers directly rather than headphones alone. The anodized aluminum chassis comes in midnight black or silver, with the amplifier's signature tubes visible through a glass top panel.

That glass top isn't just a design flourish. It keeps the tubes on display while still shielding them from dust and accidental knocks on a crowded desk. Woo Audio has used this look across the WA7 line since the original model, and Generation 3 carries it forward.

An ESS Sabre DAC, Now With Speaker Outputs

An ESS Sabre DAC chip handles digital decoding up to 24-bit/384kHz PCM and DSD256 at 11.2MHz. Frequency response spans 10Hz to 46kHz within -3dB. Signal-to-noise ratio is rated at 100dB.

The balanced 4.4mm Pentaconn headphone output delivers over 1.5 watts per channel into 4 ohms. A 6.3mm unbalanced jack sits alongside it for headphones without a balanced cable. Both outputs draw on the same tube circuit.

New preamp outputs round out the back panel: a balanced 4.4mm output at -3.4V, and an unbalanced 3.5mm output at -1.7V. Either one can feed a power amplifier or a pair of active speakers.

Digital input comes through a single high-retention USB connector, with an RCA analog input available for other line-level sources. The internal linear supply runs on 115–230V AC. It measures 5.25 by 4.8 by 6 inches with the glass top installed and weighs 8.5 pounds.

Who Is This Amplifier Best For?

• Listeners who want genuine tube sound without extra boxes. A built-in linear power supply means no external brick cluttering your desk.
• Anyone who wants a headphone amp that can also run speakers. New balanced and unbalanced preamp outputs let the WA7 feed powered speakers or a power amplifier directly.
• Owners of headphones with a balanced cable. The 4.4mm Pentaconn output delivers over 1.5 watts per channel into 4 ohms.
• Listeners who value upgradeable tubes. PTFE sockets keep the 5963/12AU7 tubes easy to swap as they age or as your taste changes.
• Not the right fit for anyone needing a portable amp. The WA7 is a desktop unit built around an internal power supply and glass enclosure, not a battery-powered design.

How Does It Connect to Your System?

Connect a computer to the USB input, or run a cable from another source into the RCA analog input. Plug headphones into the 4.4mm balanced or 6.3mm unbalanced jack, whichever matches your cable.

To use the WA7 as a preamp, run its balanced or unbalanced pre-out into a power amplifier or a pair of active speakers. Give the tubes a few minutes to warm up before critical listening.

Pairs Well With

Building your system? Here are some great companions for the Woo Audio WA7 Fireflies Generation 3:

• Headphones with a 4.4mm balanced or 6.3mm unbalanced cable
• Powered speakers to build a compact desktop system via its preamp outputs
• USB cables to connect a computer or digital source

Frequently Asked Questions

How is Generation 3 different from earlier WA7 models?

Generation 3 adds a built-in linear power supply, so it no longer needs an external supply. It also adds balanced and unbalanced preamp outputs, letting it drive speakers as well as headphones.

Can I use the WA7 as a preamplifier for speakers?

Yes. Its balanced 4.4mm or unbalanced 3.5mm pre-out can feed a power amplifier or a pair of active speakers directly, alongside its headphone outputs.

Are the tubes replaceable?

Yes. The 5963/12AU7 tubes sit in PTFE sockets designed for easy swapping, so you can replace them as they age or roll in different tubes to taste.

Do I still need an external power supply?

No. That's the main change in this generation. A linear supply built into the chassis replaces the external unit earlier WA7 models required, so setup is just a power cord and your source and headphone cables.

What's the warranty?

Woo Audio covers the WA7 Fireflies Generation 3 with a three-year limited warranty.

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Learn More

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