ADL GT40 DAC/Headphone Amp & More (Playback 53)

Jack-of-All-Trades and Masterful, Too

I’ve long been a big fan of Swiss Army Knives, and I suppose this goes all the way back to my days as an Eagle Scout who also happened to live in Switzerland. Having a single multi-tasker that can perform the functions of a bag full of individual tools makes you feel like you’re cheating the system, simplifying your life without losing out on functionality.

Audio has seen plenty of multi-taskers over the decades, from the basic stereo receiver to the multi-channel surround soundbar. Most, however, tend to be compromised solutions, doing lots of things, but none of them particularly well. Real high-end systems have traditionally taken the opposite approach, splitting the functions into so many boxes that you need a wall full of racks just to hold them all.

This is why the Alpha Design Labs GT40 by Furutech is so interesting. It takes a 21st century approach to the audio system multi-tasker, combining a lot of the functions that audiophiles want their systems to do today. For many people it can form the centerpiece of a complete system, whether you use headphones, a desktop speaker setup, or a full-blown room filling stereo rig with large speakers.

FEATURES/TECHNICAL HIGHLIGHTS

To understand just what the GT40 can do, it helps to break down its individual functions, as below.

USB DAC

Most obviously, the GT40 is a USB digital to analog converter (DAC). This means that like a high quality external sound card, it can take a digital signal from a computer’s USB port and convert it into an analog signal to feed your system. USB DACs are one of the hottest categories in audio today, and the GT40 is ready to exploit the qualities of your downloaded high-rez audio files. Unlike older DACs, the GT40 doesn’t have an S/PDIF input to handle the output of a regular CD player, but this doesn’t mean you can’t play CDs through your system. All you need to do is play them on your computer, and use its USB output signal to feed the GT40.

ADC

Perhaps less obviously, the GT40 is also an analog to digital converter (ADC). This is the feature that really sets the GT40 apart from other similar components. Using the same USB connection to your computer, the GT40 can convert your legacy analog sources into digital files, for storage and future playback on your computer or digital music player. This also means that you can turn anything from LPs and analog tapes to radio broadcasts into files that you can store and playback on your iPod or smartphone, in addition to the computer itself.

MM/MC Phono Preamp

Next, the GT40 is phono preamp. The GT40 may have just one set of analog inputs (via RCA jacks), but it can be changed at the flick of a switch from handling a normal line level signal, to the much weaker output from a phono cartridge without requiring an additional phono preamp. It can even handle both high output moving magnet or low output moving coil cartridges depending on the settings you choose.

Line-Level Preamp

Fourth, the GT40 is a line level preamp. The stereo RCA outputs allow you to connect a power amp or powered speakers directly to the GT40. This signal can come from either the DAC fed by the USB input, or the analog inputs fed by a line level source or turntable.

Headphone Amp

Last but not least, it’s a headphone amplifier. As with the line level outputs, the headphone amp can get its signal from either the digital or analog inputs, letting it play in the other red hot category in audio these days, headphones.

What’s really impressive is how Alpha Design Labs/Furutech managed to incorporate all of these functions, without turning the GT40 into a box festooned with rows of switches and knobs. The front panel has just two buttons, a volume knob, and a headphone socket. Button number one turns the power on and lights up green, while button number two selects between the analog and digital inputs, changing color from blue to red to indicate which one is selected. Around the back there’s a USB jack for the connection to your computer, and one pair of RCA inputs with a switch to change them from line level to a phono input, with separate setting for moving magnet or a moving coil cartridges. A second pair of RCA jacks is for the line level output, and finally there’s a power socket for the included wall-wart power supply.

After reading that long list of functions you might also expect the GT40 to be huge shelf-bending behemoth, but here the GT40 breaks the rules again, packing everything into a palm sized box that weighs just a hair over 1.5 pounds. By using a wall-wart style power supply, the GT40 gets a leg up over many other small USB DACs that rely on the relatively anemic USB bus for their juice. Still, this is one area where I see the potential for further improvements, much like the after-market Monolithic P3 supply boosted the performance of the Perpetual Technologies P-3A DAC a decade ago.