Review: DDS HA-01 a superbly versatile portable DAC/Amp
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Reviewer at Sound Perfection Reviews
Feb 1, 2011
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Feb 1, 2011
DDS HA-01 Review:
Firstly I would like to thank DDS for sending me this sample for review. What I have here is an incredibly versatile portable amp/DAC, great for whatever set up you have.
This is a subjective review, all opinions expressed are my own. This unit received over 50hrs of burn-in no differences were heard. I will try and write an honest review.
Gear used: Asus M50-VM laptop (via USB and S/PDIF), Fiio X3 (via line out and coaxial) > Headphones: German Maestro GMP 400 and GMP 8.35D, Westone UM Pro30 and T-Peos H-300.

Info (from website):
Can push 8-300Ω headphone, GAIN switch gain boost +6 dB,
IN / OUT PORT - USB / Coaxial decoding.
USB - insert the USB connected to the computer, LINK indicator ON, conversion chip TAS1020, up to 24bit/96khz digital audio,
SRC - when you open the USB / optical / coaxial audio input USB / optical / coaxial audio input Wolfson's WM8740 decoding sampling rate will rise to 192KHZ frequency output,
COAXIAL IN coaxial input, the use of ultra-low-Wow and flutter Cirrus Logic CS8422, up to 24bit/192khz.
MSRP: $270 (£160)
Power: Built-in 4.2V rechargeable lithium-polymer battery discharge 
output power: 320mW (32Ω load) 
Frequency Response: AMP: 10Hz ~ 100KHz (± 0.5dB) 
USB: 20Hz ~ 20KHz (± 0.5dB) 
Gain: +3 / + 9dB 
​​Distortion: 0.004% (1KHz) 
SNR: 104dB 
Headphone Adapter Impedance: 8Ω ~ 300Ω 
life time:> 17H (DIGITAL),> 23H (AUX), 
charging time: <4H 
Dimension: 109 * 55.5 * 15mm 
Weight : 110g
Packaging, Accessories and Build Quality:
Packaging is a simple white box with DDS HA-01 written on the front. A few details are also included on the box, not the most luxurious packaging, but protects the amp/DAC well.
Accessories include a short S/PDIF optical cable, adhesive rubber feet and a charging cable. Some amp straps would be a nice little extra but I cannot complain, everything you need is included.
Build quality is good, all sockets feel sturdy and solid, the volume knob is also the on/off switch and has a very satisfying click on and off and also a smooth rotation. Switches are also fine, they don't stick out a lot and wont snag easily, and also are placed so that they won't be activated by accidental knocks.

Input's/Output's and Operation:
The HA-01 is a very versatile amp/DAC combo, it has a huge array of input's and output's which make it the perfect out and about device.
On the front you have the headphone output, and the line-in for LOD's or line out cables to plug in to, but this also doubles up as a line out for the DAC section so it can be used as just a DAC too.
Also on the front is the gain switch which allows you to choose between +3dB an +9dB of gain, making it suitable for all but the most power hungry of headphones, the volume knob and power indication light are also on the front panel. The headphone out and line in sockets are far enough apart for most 3.5mm jacks.
On the back you have a 3.5mm Coax input, SRC switch which changes between the limited Coax input (max 24bit/96kHz) and SRC On which uses the Wolfson WM8740 (192kHz), Charge/On switch which allows you to charge the HA-01 from your device/PC or use the internal battery, Micro USB input, and Optical input.
I have used the Coax input from the Fiio X3, the Optical from my Laptop and USB from my laptop too. This device should work with Android devices but I have yet to test this. Lights also let you know if it is connected as a DAC and if it is charging.
So as you can see it is an incredibly versatile unit and all in a very small package with good battery life, so what about the sound?

Coax in from the Fiio X3 sounds really great, more refined and detailed than the headphone out of the X3, this allows you to hear all the micro detail that was missing from the slightly warm sounding X3, the sound is full but not thick, it is fast and articulate but may lack a tiny bit in the sub-bass, as the sound is quite linear and flat. The highs are sparkly yet not grainy or harsh, you really notice this on the slightly hot sounding H-300, this somewhat controls the highs of the H-300 making them slightly less fatiguing to listen to. Overall I really enjoy this combo, it also works very well with the Westone UM Pro30 giving them a little more air and clarity, taming the somewhat thick lows of the Westone.
Line-out from the X3 also works remarkably well, having most of the same sound as the above but a tad leaner, and a tad less micro detail but overall it works very well with slightly warmer headphones.
S/PDIF from my laptop sounded fine, detailed and tight, and this is a great feature if you have a DAP with an optical out socket, but I prefer to use the USB out from my laptop, just sounds a little more natural and full.
USB out from my laptop is great, this device is just powerful enough to power the hungry German Maestro GMP 400, and does a good job of it, the GMP 400 are a little on the leaner side of neutral and this does not change that completely, it does have a little more body but still retains all the glorious detail that I love from the GMP 400. The sound is lush and articulate, a tiny bit of roll off up top but this does not detract from the overall performance from this tiny device.  Lows are full and have great decay, the mids are airy and detailed and the highs are smooth yet still sparkle with good extension.

This really is a jack of all trades which you should be amazed at the versatility, it will work in all systems and the SQ is remarkable for the size of the unit. In all the combo's I tried it in, the sound stayed similar with slight changes between the inputs. My favourite was the USB but the Coax came very close. The device has a good amp too being quite flat and neutral maybe lacking a tiny bit of sub-bass. The only thing I could want more from this device is a bass boost like the JDS Labs C5D which I also have.
The size of this DAC/amp pairs perfectly with the X3 and the combo sounds great together and is not a huge stack.
There is some stiff competition in the price range, but few are as versatile as the HA-01 with as good battery life, the C5D has the smooth refined sound, and great digital volume control with 3 way bass boost, but lacks the array of inputs that the HA-01 has, so the C5D has the upper hand in SQ but the HA-01 in versatility.
Depending on your needs, the HA-01 is definitely one of the most versatile pieces of portable audio gear any audiophile needs, it is cost effective and great if you commute a lot as you can use it on your commute and at your desk, with very little extra bulk.
Thank you for reading this review.




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