Hotaudio USB Dac2

Hotaudio is not a brand you may be familiar with, but they have quite an extensive range of headphone amplifiers ranging from battery powered to USB bus powered models. The model I am reviewing here is the Hotaudio HOTUSB 2.

Hotaudio HOTUSB 2
Price: $155.99 + $12.99 Worldwide Shipping

Hotaudio USB DAC 1 Specifications:

  • Plugs Right Into Your Computers USB Port
  • 3 Foot USB Cable Built Into Amplifier
  • Self Powered from the USB Port on your computer
  • Self Installs – No Special Drivers Needed as Long as you have a Working USB Port
  • Fully Compliant With USB 1.1 Specification
  • SNR = 98 dB
  • Extremely Low Jitter
  • Dynamic Range: 98 dB
  • Sampling Rate: 32, 44.1, 48 kHz
  • Power Output = 12 mW, R = 32Ohms
  • Works with 30 to 300 ohm headphones
  • THD+N: 0.006% R = 10kOhms
  • THD+N: 0.025% R = 32Ohms
  • Runs off USB port and uses NO batteries
  • Plug and Play Technology
  • Has 3.5mm Stereo Headphone Output Jack on front
  • Dimensions: 6.5mm by 6.5mm by 3mm ( 2.5 inches by 2.5 inches by 1 inch )
  • Weight: Approximately 100 grams

Hotaudio sell their products direct from their website or via the eBay seller: Hotaudio40. I chose the eBay option. The seller is very courteous via email and answers question with knowledgeability and politeness. Rare in this day and age.

hotusb audio back

I received my HOTUSB 2 roughly 7 days after it was posted from Canada. I live in the UK and considering the usual delay in customs, arrived on time. The HOTUSB 2 came in a small box and was well packaged. Included in the box was an instruction leaflet and a HOTUSB 2 with about 1 meter of USB cable.

The HOTUSB 2 is based around a Texas Instruments PCM2707 chip. This combines a DAC and an headphone amplifier into one chip. Having everything you need built into one chip is very convenient and this contributes to the HOTUSB 2’s low cost. Everything inside the USB DAC 1 is soldered by hand using silver solder. From an audiophile’s point of view, this will give the cleanest signal path.

According to the website the HOTUSB 2 works with Windows 98SE upwards and Mac OS 9 and upwards. I use Mac OS X Leopard (10.5.2) so I thought I would try the HOTUSB 2 with this.

I plugged the HOTUSB 2 into a free USB port and it was detected as a USB DAC within a few seconds. I plugged in a pair of Grado SR-60 headphones and began to play some music via iTunes. It worked. Plug and Play at its best. For the first time since I had my Mac, I was hearing something close to Hi-Fi quality sound. Bass was deep and yet taut. Treble was clear and precise and everything was presented with an openness I have not experienced before on a computer. As you can see in the picture below, the volume, balance and mute are controlled by your computer.

usbdac-os x

I opened up VLC and Quicktime to play various Movies and again the sound worked flawlessly. No hiss, no pops, no crackle, no sync issues, just a pure and open sound. I tried to stress the USB DAC 1 out by connecting it to a USB Hub and plugging in as many USB devices as I could find. Another USB soundcard, 2 external Hard Drives, a wireless keyboard and mouse, Sony Eyetoy webcam and not once did it phase the HOTUSB 2. It just worked.

That was on an Apple Mac Mini, what about using Windows XP or even the newest Microsoft Operating System, Windows Vista. Surely it would have problems in one or both of these? Well, I am happy to say it didn’t. It took a little longer to detect and install compared to the Apple Mac Mini, but it did work. I wasn’t prompted for any CD at any point and again, the HOTUSB 2 just installed and worked flawlessly.

Like most audio devices, you are advised to run them in for a little while for them to sound at their best, so I did this with the HOTUSB 2. I left it connected for over 24 hours with some of my iTunes albums on repeat. Did it make a difference? Well, the bass become slightly warmer and the sound is a little more open than before, but as it sounded quite good to begin with I had to listen hard to notice.

I have been using the HOTUSB 2 for well over 2 months now and it has replaced my previous setup, a Sound Blaster 24 Bit external USB soundcard connected to a Phillips SBC-HD1502 Dolby Headphone decoder. I thought nothing could touch the Philips for surround sound through headphones, but even without Dolby Headphone, the neutralness of the HOTUSB 2 combined with the openness of the Grado SR-60’s provides a much more enjoyable and accurate sound.

I did try other headphones such as the iGrado’s (rated at 32ohm) and a pair of Goldring NS1000 (rated at 330ohm) and the HOTUSB 2 drove them both with ease. Which will surely put the minds of those with high impendece headphones at ease.

I do like the HOTUSB 2 a lot. Not only does it sound great, it has changed the way I think about computer audio. If you want the best sound your computer can muster without spending a fortune, I can not think of a better way to do so.

Update 1:

Hotaudio have informed me they are mainly PCM2705 IC’s now. However the PCM2707 IC and   PCM2704 IC can be ordered as a special request. “The PCM2705 has a little more PUNCH but still sounds very accurate” I am told.

Contact Hotaudio for details:

Honglong’s Rating:
Great value for money USB DAC, with brilliant OS support and drives difficult headphones with ease.

9 out of 10

plus sign

+ Hi-Fi quality sound on your computer
+ Amazingly for a USB device I didn’t get one single problem
+ Drives low and high impendence headphones with ease
+ Hotaudio’s email support is superb. Hotaudio are obviously passionate about their products

minus sign

– Minimalist looks won’t suit everyone
– Personally I would prefer a detachable USB cable

Update 2:

I have been informed by Hotaudio that there is a model with a detachable cable and it features one of the newer DAC IC’s. The model is called HOTUSB 1.

Here is a photograph of the HOTUSB 1: