I took a chance and purchased this unproven product for $139 as an initial backer, long before production began. The price was as low as $99 for early backers, which was a screaming deal for a USB DAC. Mine has the blue finish with 720 milliwatts output, they were also available in 450 and 1,000 mW versions in various colors. The Geek Out is an exceptional product. It is made in the U.S. and is sturdy and well made. It took some effort to get this gadget to work on my Windows 7 laptops. There are 4 pages of instructions on Windows driver installation, but the process was quick and fairly easy. Installing new firmware was more difficult, but fortunately after one install it is no longer required. Please heed the warnings about reducing volume before playing music! The Geek Out produces a lot of power that belies its small size. I first played high resolution files, and its absolute clarity and realism was simply stunning, even with modestly priced headphones. It also significantly improves the sound of ripped CDs, DVDs and MP3 files. Disadvantages: Since drivers must be installed on Windows PCs, the Geek Out usually cannot be used with public computers, such as library computers. I have since purchased a refurbished Audioengine D3 for only $119. The D3 doesn't require software installations and updates, sounds great and works fine with any computer. However, the Geek Out sounds better.
Update: I recently installed a new driver, again it was easy using the LH Labs website instructions. I'm now using a audioquest JitterBug USB filter with my DACs, with this filter and the updated driver the Geek Out sounds better than ever, and works seamlessly with Windows 10 and JRiver Music Center. JRMC settings for the Geek Out are here: tinyurl.com/JRMC-GeekOut Lightly used Geek Outs are occasionally available at echohifi.com at great prices.
Update: I recently installed a new driver, again it was easy using the LH Labs website instructions. I'm now using a audioquest JitterBug USB filter with my DACs, with this filter and the updated driver the Geek Out sounds better than ever, and works seamlessly with Windows 10 and JRiver Music Center. JRMC settings for the Geek Out are here: tinyurl.com/JRMC-GeekOut Lightly used Geek Outs are occasionally available at echohifi.com at great prices.
For me, there is no reason to do so as the a class amp is the best part of the GO and the reason I purchased it. If I was just looking for a source for my amp, I would probably just use my DX90 or X5 and gain my music library for better usability. The only reason that i am hearing people using another amp is to avoid the horrific volume spike issue. For me, I just add caution to avoid that by adding a couple additional steps when setting up.