We’ve been looking for a USB tube pre-amplifier to sweeten the sound of digital music files as they travel between a computer and a sound system. That quest continues, but it has revealed something similar, and possibly superior. Glow Audio, a subsidiary of Hercules Soundworks, told us about their all-on-one USB tube amplifier that connects computers directly to speakers or headphones, the Glow Amp One.
The company recommends that the Amp One be used with relatively sensitive speakers due to their relatively low power output, but claims that analog amps put out cleaner, more even sound that requires less volume in order to achieve clarity.
People are always talking about tube amplifiers’ "smoother, warmer" character, which the company hopes is worth $488 to the avid digital music listener. Glow points out two reasons for the difference between analog and digital amplification. First, transistors create a signal with faster transients (essentiallya sharper attack) and "higher amounts of odd orderharmonic distortion," otherwise known as transistor hash.
Although its amplification approach — passing electrons from cathode to anode — is pure old school, this amp is 100 percent compatible with all file formats and every form of DRM. The Amp One is a standard USB audio device, so it can play anything your computer can play.
The overriding sonic principle idea here — as with lots of high-endaudio equipment — is to use as little electronics as possible toamplify a signal. A shorter and cleaner signal path meanscleaner sound. According to Glow,
The Amp One works with any computer made within the past ten years or so, because Windows 98 SE First Edition was the last major operating system to lack the USB audio profile. The device’s analog input mean you can also use it with MP3 players, but listening to the files through a computer’s USB port makes for fewer analog/digital conversions and therefore better sound.
Here are the full specs — more images below.
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Speaker output impedance: 4Ω~8Ω Headphone output impedance: 32Ω~600Ω Output power: 5W×2 at 1KHz (earphone: 600mW) Frequency response: 10Hz-30KHz (-1dB) T.H.D: <1% (1W) S/N Ratio: >89dB Input Impedance: 50KΩ Input Sensitivity: 650mV USB Sound decoder: 16BitΔ?∑ decoder; USB connection Vacuum tubes: 6N3×2, EL84×2 Power consumption: 38W Power requirement: switchable 110V/220/230V AC, 50~60Hz Dimensions (L x W x H): 11.5" X 5.5" X 6" (238 mm x 138 mm x 148 mm) Line-in connection: RCA stereo jacks Speaker connections: Two binding posts Accessories: power cord, USB cable Headphone jack: stereo (6.35 mm diameter) Net Weight: 14.33 lbs Shipping Weight: 16.5 lbs
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The Amp One’s tubes hide behind a grill:
Here’s a side view of the silver one:
The Glow Amp One also comes in red, black, or yellow:
Photos courtesy of Glow Audio
