Alpha Design Labs GT40a Alpha USB DAC with Phono Stage

"Five Stars" - What Hi-fi? Magazine

"A Hell of a Good Thing," Says Stereophile

The ADL GT40a from Alpha Design Labs is built for enthusiasts with growing music collections on their computer hard drives. It's a high performance 24-bit/192 kHz USB DAC that's amazingly affordable. Enjoy audio in true high resolution audio at 24-bits/192 kHz for way, way better than CD-quality sound. Looking to convert your LPs or other analog sources to digital? The GT40a has built-in technology to take you there, plus an audiophile headphone stage.

With its new 24/192 DAC and ADC, the GT40a upgrades the critically acclaimed ADL GT40, which received a top rating of Five Stars from England's What Hi-fi? magazine. "It's a real Swiss Army knife of a product – and it performs admirably. The on-board DAC is excellent." According to the magazine, "If this unit were judged solely on DAC performance it does enough for a five-star verdict. But it's way more than that…"

"A Loud Bravo is in Order!"

"The Alpha Design Labs-Furutech GT 40, like its maybe-namesake [the legendary Ford GT-40], is one of those things no one saw coming from any direction: a hell of a good thing," reports Art Dudley in Stereophile, September 15, 2011, writing about the original model GT40.

"From this point forward the GT40 is my new reference preamp recommendation below 10.000zł [$3,200] period," raves Wojciech Pacula in an April 2011 post for 6moons.com. "Considering price, a loud bravo is in order!"

Built-in Phono Stage for Archiving Vinyl

The seriously-shielded, audiophile-grade GT40a features a low-latency USB 2.0 audio driver that plays and records at 24-bits/192 kHz. Looking to convert your LPs or other analog sources to digital? In a likely first for this category, the GT40a includes a built-in low-noise MM/MC phono preamp, too! That means you can connect your turntable directly to the GT40a without the need for an external phono stage or preamp with phono stage. Record your favorite vinyl to hard disk via the USB output. You'll find lots of software online to help you with this easy task, including free Audacity software.

You can use the GT40a to convert other analog sources to digital, too. It incorporates a high-performance 24/192 analog-to-digital IC chip for high resolution recordings via analog inputs such as a tape deck, AM/FM radio, or the line-out jack of a portable music player.

Vivid, Captivating Sound Quality

The ADL GT40a features left and right analog outputs along with switchable line or phono inputs with a vivid, captivating sound that is simply unheard of in this category. The ADL GT40a (wired with Furutech's GT2 USB cable) brings Furutech's signature sound of smooth, detailed clarity to desktop systems. Even 16-bit/44.1kHz files sound impeccable and very musical.

An external power supply gives the GT40a the edge over other USB DACs. While a USB-powered device might be convenient, it may not be able to develop the power required for high resolution playback. So ADL designed the GT40a with an external power supply to solve the problem.

Highest Quality Parts

The GT40a features a high quality amplifier and condenser supporting its high performance analog circuit. The GT40a is equipped with high-end, audiophile-grade gold-plated fluoropolymer-insulated RCA jacks. The GT40a's casework consists of an extremely high quality aluminum chassis and machined volume knob.

• High performance 24-bit /192 kHz USB DAC and 24-bit/192 kHz ADC IC chip
• Enjoy audio in high resolution at 24-bit/192 kHz surpassing conventional 16-bit/44.1KHz standards
• Incorporates the most trusted driver in professional audio for 24-bit/192 kHz recording and playback
• External power supply
• High performance headphone amplifier with ample drive capability
• High-performance ADC IC chip for high resolution recordings via analog inputs including phono, AM/FM radio, or other analog signals.
• Convenient Clip signal Toggle switch for Recording Attenuation: Adjust the recording attenuation to avoid any distortion during recording: 0dB, 6 dB, or 12dB
• Phono Preamplifier: Switch between Moving Magnet (MM) and Moving Coil (MC) or Line input
• Highest Quality Parts: The GT40α features a high quality amplifier and condenser supporting its high performance analog circuit
• High End Audio Grade Connections: The GT40α is equipped with gold-plated Teflon-insulated RCA jacks
• Extremely high quality aluminum chassis
• Machined volume knob

General Specs

• USB & Analog Playback and Record multimedia audio system
• Connectivity: USB B Interface, Analog input/output RCA jack
• USB Playback Resolution: 24-bits/ 192 kHz (Max) USB
• Recording Resolution: 24-bit/192 kHz (Max) supports 44.1 /48 /88.2 /96 /176.4 /192 (kHz)
• Frequency response: 20 Hz ~ 20 kHz (+/-0.5 dB)
• SN ratio: >90dB (A-wtd) / Line Output
• Line Output Level: 5 Vrms
• Line Input Level: MC 0.4mV / MM 4.0mV / Line 2Vrms
• Headphone Output Level: 1% THD 1kHz (Max.) 94mW (16 ohm), 110mW (32 ohm), 98.6mW (56 ohm), 23mW (300 ohm)
• Power Supply AC Adaptor Rating: Erp step2 compliant, 2Wire AC Input Type, Class II, AC/DC Switching Adaptor output DC 15V / 0.8A / 12W
• Dimensions: 5.9" wide x 2.2" high, 4.3" deep
• Weight: 1.43 lb Approx.

• Maximum Input Level for MM: 4.0mVrms at 1K Hz
• Maximum Input Level for MC: 0.4mVrms at 1K Hz
• Maximum Input Level for LINE: 2Vrms at 1K Hz
• The load (input impedance) setting for the ADL GT40 is fixed at 47K ohm for MM and 100 ohm for MC
• (MC input to LINE output) => 62.5dB @ 1K Hz , +6dB(Line)
• MM input to LINE output) => 48.5dB @ 1K Hz , +6dB(Line)

Note: The GT40 has no setting for gain to match different impedance headphones. ADL recommends using 16 ohm to 300 ohm impedance headphones.