Review: DDS DAC-01 (mighty DAC+Amp combo)

I would like to thank DDS for sending me this sample for review, I will write as honest a review possible. This DAC/Amp received well over 100 hours of burn-in, no real difference were noted. Most of this review was done with a Mullard 12AU7 Tube (upgrade) and towards the end I put in a LME49720NA op-amp too.

Gear Used:
iPod Classic 7G > Line out  > DAC-01
Asus M50vm > USB > DAC-01
Marantz CD-52 SE > Coax > DAC-01
(various headphones, but mainly German Maestro GMP 400)

Tech Specs:
Output Power: 2000mW (32Ω load)
Digital inputs: USB, optical, coaxial 16-24bit / 44.1-192KHZ Signal
Frequency Response: AMP: 10Hz ~ 100KHz (± 0.5D B)
USB / OPT / COA: 20Hz ~ 20KHz (± 0.5 dB)
Gain: +6 / +16 dB
Distortion: PHONE: 0.005% (1KHz, 32Ω load)
LINE OUT: 0.002%
XLR OUT: 0.0009%
SNR: PHONE: 114dB (1KHz, 32Ω load)
XLR OUT: 125 dB
Analogue output amplitude: RCA: 2Vrms
XLR: 2Vrms
Adapter Headphone Impedance: 8Ω ~ 600Ω
Dimension: 306 * 208 * 67mm
Weight: 2.75kg

Packaging, Build Quality and Accessories:
Well packaging I cannot say much about as it was just shipped in a big box, with a foam cut out to securely hold the DAC-01 whilst shipping, very well packaged and protected.

Accessories also were not included, as I had to get a UK kettle type cable, and a USB cable I already have. But I think a USB cable and Power Cable (depending on country) should be supplied, a 6.3mm to 3.5mm adapter would also be handy.

Build quality feels fantastic, it is a heavy, solid piece of kit, all metal casing which all fits together well, the finish is good, and it feels very sturdy. The headphone output is of excellent quality, the inputs on the back, and outputs are all sturdy and they all fit flush with the case. The volume control is stepped and all buttons click satisfactorily. The design is very minimalistic and sleek, with the power button, headphone out, function buttons and volume knob on the front, and all inputs and speaker outputs are on the back.

It is easy to set up, plug in, download driver (if you're using USB), and you are all set to go. The input button obviously changes the input, SRC changes the sample rate, Listen is the tube output (on or off), and then you have Gain which is either +6 or +16. Very easy and simple to set up and get used to the functions.

Well this is what it is all about, it has a very powerful headphone amp, that will be able to drive all but the most difficult headphones with ease, my inefficient German Maestro GMP 400 only need to be in the 12 o'clock position (+6 gain) when using Coax in from my Marantz CD-52 SE.  With the line-out from my iPod it is usually on around 2 o'clock on the volume.

Line-in sounds great with both tube enabled and disabled. With the stock chinese tube, it is quite mid focused and also the treble seems quite upfront, the Mullard tube is much more relaxed and lush, more like the tube sound that goes so well with the GMP 400 and 8.35 D. Having the tube enabled just gives a tiny but more body and warmth, but not too much as to take away the detail.

With the Tube disabled, the sound is more linear, I did not notice a huge difference changing from the stock op-amp to the LME49720 NA  but it is one of my favourite op-amps, because of its clean sound and good detail retrieval, plays very well with my GMP 400.

USB in has one problem, which is more of a problem with my laptop, but I thought I would mention it, it does not like noisy USB ports, you can clearly hear all noise from the laptop through the USB port, so it meant I had to use a dual headed USB cable (iFi Gemini) one end plugged in to my laptop (Audio) and the other to a USB wall plug to eliminate the noise.
If you have a clean USB port, then it is great, and the DAC works fine, and sounds great, very transparent and clear with just a touch of warmth and body.

Coax sounds just fine, no problems with noise or quality, again a very clean sound, and if you want a little extra flavour turn the tube on.

It plays fine from my laptop using the optical in put (s/pdif out from my laptop) with no noise problems. So it is just the USB that is noisy on my laptop. Again the Optical in works a treat, great for pairing with a TV and speakers, or straight to headphones.

It is hard to find any fault apart from the noisy USB, the rest it just does very well,  it is very versatile with all the inputs and outputs, it even has balanced outputs for speakers, which unfortunately I have nothing to test this with.

It seems that this versatile DAC works well with most sources, and has a very powerful headphone amp. I can see myself using it mainly with my speaker setup as a DAC between my CD player and Amp, and using it as just a headphone amp with my iPod Classic. I find my iFi Audio iDAC to have better clarity and detail in terms of USB reproduction, but the DAC-01 is just so much more than a simple DAC, it can be integrated in to most systems and sound great.

The top panel is easy to remove so you can swap out op-amps and tubes when and if you feel like it.

I would recommend this device as a desktop amp/DAC for hard to drive headphones, and I like the fact you can choose to have the tube on or off. It is also versatile in the amounts of inputs, which means it will work with a wide range of devices. The only thing to be careful with is the USB noise, it must be some grounding issue, but is clearly audible when playing quieter music.
This device is also cheaper than the stack I have, the iFi iDAC + iCan + iTube, and it all that they do in one package, but obviously the iFi stack does sound marginally better, but to be honest the DAC-01 is more powerful and gets more ear time when I'm not at my computer.

DDS seem to like versatile devices, their HA-01 portable DAC and Amp is also brilliant with an array of inputs and outputs.

Thanks for reading.