Monday, January 23, 2017

Vinshine Audio DAC-R2R Ref

Introduction

R2R DACs seem to be all the rage nowadays. However, not everyone can afford the DACs from MSB or Totaldac. Luckily we do have some more affordable options now. Soekris Engineering brought discrete resistor R2R to the masses, with an affordable full populated board - just add a suitable power transformer and you were effectively good to go. Wait a minute - can't read a circuit diagram to save your life, and scared of handling potentially lethal voltages ? Have no fear - our very own local company, Vinshine Audio has come up with a ready made product utilising a Soekris board. My review model came with the Rev 3 0.02 % board.

To an oldie audiophile like me, the fuss about R2R is quite amusing. When I started out in the hobby, all CD players utilised R2R DACs. A short while later, Philips started extolling the virtues of bitstream DACs. In fact, I secretly lusted after a Marantz CD 10 that used a bitstream DAC.

Fast forward to the present, and the DAC in my main setup is an R2R DAC, while the DAC in my second setup is a Delta Sigma design. The rest of my spare DACs are an even mix of both. You can get great and truly awful sounding DACs that fall into both camps. A DAC is built from far more from the decoding chip alone - the technical implementation, power supply and output stage etc. all play an important part in the quality of the finished product.

Some history about Vinshine Audio - this is a Singapore company started by Alvin Chee. Alvin is quite active in our local audio forum and has been helping us to get our hands on affordable audio products for a while. He has a long standing collaboration with Jay's Audio in China, and this DAC is designed by Vinshine but manufactured by Jay's Audio.

The heart of this DAC is the Soekris R2R board - you can read all about the Soekris board here

Description

The Vinshine Audio DAC-R2R Ref is finished in satin black and feels solid - it is much heavier than it looks. It has compact dimensions at 300 (W) x 290 (D) x 80 (H) mm (excluding feet and the sockets / knobs) and weighs 6.4 kg.  




The unit feels sturdy and solidly finished. I really like the design. The silver knobs and name plate on the fascia looks very classy and elegant, with a nice contrast to the black colour of the unit. The knob on the left is the input selector, while the knob on the right is the volume control. A toggle switch on the right switches the DAC between fixed volume and variable volume mode. Twin 6.3 mm sockets allow headphone listening with your favourite person (just remember to use headphones of similar sensitivity since there is only one volume knob). The four blue LED lights indicate the selected input and variable volume mode.




The back panel has a pair of single ended and balanced analog outputs, three digital inputs (USB, AES and coaxial - the latter two inputs are transformer isolated), and the power switch. You also have an RS-232 female DB-9 socket, which allows you to upgrade the firmware of the Soekris board and upload new digital filters. Despite the labeling, there is no I2S input. Another oddity is the orientation of the analog outputs, which place the right channel on the left, instead of the conventional placement of using the right side. No instructions or cables are provided for the firmware upgrades and filter uploads, so you are left to your own devices to fiddle around. 


Parts quality used is high, with twin Noratel transformers for the internal linear power supply - one each for the DAC board and headamp circuit board. A super regulated circuit is used to supply the DC voltage rails for the DAC board which should result in very low ripple, while the headamp board relies on LT137/337 precision regulators. Premium capacitors in selected areas are used such as Nichicon Muse and Rubycon ZLH.

The asynchronous USB input is handled by an Amanero board. It played all my test files without any issue, including DSD. 

The analog outputs are taken from the buffered audio output circuit on the Soekris board (the Soekris board also offers a direct output, trading off drive and output impedance).

The headphone amp board has a socketed opamp, so feel free to experiment to get the tone you like. The stock opamp provided is the Burr Brown OPA2134P.

Some words on the volume control, the toggle should be activated with the unit powered down, to avoid the Soekris board latching on to it's +10 db mode (a built-in feature). I forgot to do that and ended up clipping my preamp input. Also, note that the volume pot directly accesses the volume control in the Soekris board which is a digital-domain volume control. 28 bit resolution allows a little bit of headroom for digital attenuation before you start to have data loss.

I inserted the Vinshine into my main system, replacing my Totaldac D1-dual. I used the AES digital input most of the time, and the balanced analog outputs (converted to single ended using Totaldac converters, which are transformer based).

Sound Quality

The review unit was kindly burnt-in by Alvin. For good measure, I put another 48 hours of continuous play through my preferred digital input and analog outputs for good measure. I found that the Vinshine reached an optimal state of performance after extended warm-up time - at least a day or two. The casing was just slightly warm to the touch, you should leave this continuously powered up.

Listening over several days, I found the Vinshine to have an inverted "smiley-face" frequency curve - with a lack of extension of both frequency extremes. This is quite subtle, and I noticed this as reduced slam on large scale orchestral works, as well as subdued energy in the shimmering of cymbals and ambience. There was some smoothing over of detail in the midrange, but otherwise the Vinshine was quite detailed and resolving. 

Tonally, the Vinshine is a sweet and laidback performer. It has an easy-going and relaxed demeanour which should make it a perfect companion to enjoy an evening unwinding (with your beverage of choice). It's polite presentation will also take a bit of edge off spitty and more raw sounding recordings. 

Soundstaging is spot-on with appropriate width and depth, with accurate placement of instruments and vocals. I did find that the Vinshine sounded smaller in scale compared to my reference equipment, so perhaps it is not the first choice if you like listening to larger scale works like orchestral pieces or rock concerts.

The Vinshine's headphone stage is quite good. It had plenty of drive, and had no problem with either my Beyer DT-880 (250 ohm version) or Sennheiser Massdrop HD6xx headphones. However, hiss was quite noticeable with my Ultimate Ears Superfi 5 IEMs.

From a value perspective, the Vinshine is outstanding. You get very competent performance from both the DAC and headphone stage. It punches well above it's weight and compares very favourably to it's competitors. 

Conclusion

The Vinshine is a very nice piece of kit at it's asking price. It has a likeable character, although it tends to favour certain genres of music more. Recommended.

Vinshine Audio

http://www.vinshine.audio
Email : vinshineaudio@gmail.com
Recommended Retail Price : USD 1,480




Sunday, January 1, 2017

Neutral Cable - USB Reference I (Improved)

Introduction

Italian hand-made things are beautiful - artistic, and made with passion and flair. You may not necessarily agree with their aesthetics, but they invariably make a statement !

Neutral Cable are a Rome based company that makes their cables by hand. The cable on test here is the USB Reference I (Improved) and is their flagship USB cable. The conductors used for data are made of teflon insulated 7N purity solid core silver wires. Meanwhile, the power supply conductors are shielded and spaced from the data cables to avoid interference.

The new improved version promises better separation between instruments, better dynamics and articulation of low frequencies compared to the USB Reference.

My review sample came in a nice velvet case. The 1.2m cable was sheathed in a nice bright yellow jacket and was neatly and well-made with a single USB head (Neutral Cable's website mentions that a double-head type cable can be made upon request). 






The USB Reference I is Neutral Cable's flagship USB cable and is priced at EUR 500/600 for 0.8 / 1.2 m lengths. That puts it comfortably in the territory of other highly regarded cables like the Wireworld Platinum Starlight, or the JCAT Reference USB.

Sound Quality

According to conventional audiophile wisdom, silver cables have a fast, bright and detailed tone. My own experience with silver suggests otherwise, with pure silver cables sounding detailed, very smooth and full. Some people say that silver cables have very weak low frequencies. I personally think this is a result of using very thin silver conductors to keep costs low. 

In any event, the Reference I is a highly detailed, full sounding and very musical sounding cable. It is quite smooth too, with a fluidity that is totally free from grain. How about that, from a silver cable ?

Tonally, the Reference I avoids the precision razor sharp sound of some cables that emphasise the leading edge of notes, but usually end up sounding fatiguing in the long run. Instead, the Reference I has a full bodied sound, with fleshed-out images. More importantly, it does this without sounding dark, smoothing over details, or rolling-off the top-end of the frequency spectrum. Some users may find that the transients are slightly soft-sounding and lacking in snap though - it depends on your musical diet and preferences. 

Low frequencies have a nice bloom and wetness to it, with some fullness in the midbass. Compared to my Wireworld Platinum Starlight (Series 6), it lacks some punch in the lowest registers. 

Both the midrange and high frequencies of the Reference I are balanced, with a highly detailed and controlled sound. There is a sweet and effortless presentation that makes vocals very easy to listen to. The Wireworld in comparison sounded aggressive and a bit bright.

Imaging is well-sorted out, although image sizes are slightly larger than usual, with a subtle forward projection of the soundstage.

The character of the Reference I was consistent - I tried it in two different setups and my listening notes for both were generally similar. 

Conclusion

It is really easy to like the Reference I - it's relaxed, sweet and very natural sounding. It has a wholesome sound that is highly detailed yet effortless. It's certainly not a cheap cable, but I consider the asking price to be well justified by it's performance - Recommended. 


Neutral Cable

USB Reference I - EUR 500 (0.8m) / EUR 600 (1.2m)
http://www.neutralcable.it/