Sunday, February 26, 2017

Holo Spring Level 3 DAC - A mini review

Introduction

I recently spent a few quality days with the Holo Spring Level 3 DAC, courtesy of Sound Affairs, Singapore distributor for Holo. There is plenty of chatter in various audio forums on the Holo Spring DAC, especially on the high level of performance it delivers for it's price.

Description

The Holo Spring is a really nice looking DAC (I adore those copper side panels), and is solidly built. It probably has the largest display I've ever seen, and the dot matrix panel is fully legible even from my listening position. 

The Spring DAC is a R2R DAC design. What differentiates the Spring from the rest of it's competition is that fact that DSD is decoded using a R2R circuit too. This is achieved by having two separate R2R circuits - one for PCM and the other for DSD.

The front panel has four buttons. The first button puts the DAC in standby mode, while the rest of the buttons control the display intensity, oversampling mode and source. There are four oversampling modes, NOS (no over-sampling), OS (both PCM and DSD are oversampled in their native format), OS PCM (oversampled PCM - DSD is converted to PCM), and OS DSD (oversampled DSD - PCM is converted to DSD).






The rear panel has both single-ended and balanced analog outputs, while a total of 6 digital inputs are offered - USB (galvanically isolated), coaxial, BNC, AES, Toslink and I2S via HDMI (PS Audio standard). The Level 3 unit utilises a silver wire power transformer and Jensen capacitors.

In use, the Spring DAC runs quite warm. It was left powered on for the few days I had it in my system. 

Dimensions wise, the Spring DAC measures 430 mm x 300 mm x 55 mm, and weighs 8.5 kg. 

Sound Quality

I was not able to do detailed comparisons of the Spring DAC using various digital inputs or its oversampling modes due to the short evaluation period I had. However, I did find that NOS mode sounded the most pleasing to my ears. While the tone of the unit was similar via SPDIF and I2S, I had a slight preference for I2S (fed via a Singxer SU-1 USB / SPDIF bridge) and stuck to that.

The Spring DAC struck me with it's highly detailed presentation, with excellent retrieval of details. At the same time, the detail is presented in a very light-footed, delicate and silky manner. There is a noticeably warm glow and sweetness to the sound. If you find digital sources harsh and cold, you will love the Spring DAC. 

From a soundstaging perspective, there is a subtle emphasis to the midrange which is projected slight forward from the rest of the instruments. Otherwise, there is a good sense of width and depth.

Dynamically, the Spring DAC is slightly lacking in impact and speed. I also felt that strings and cymbals lacked the bite and shimmer of the best units out there. You could say that there was a certain amount of restraint and lack of rawness and energy to the Spring DAC - definitely not the first choice for Rock, Metal or EDM.  

Conclusion

The Spring DAC is a very nice performer for the price. It's tonal balance tends to favour certain genres and it appeals more to the listener that prefers a sweeter and more easy-going sound. Thankfully it does not trade resolution to achieve this, and you get a highly detailed yet easy-on-the-ear tone.

A big thanks goes to Sound Affairs Pte Ltd (local agent for Holo) for arranging for the review unit.

Holo Spring Level 3 DAC
Price : S$ 3,500

Sound Affairs Pte Ltd
100 Beach Road, Shaw Tower #02-34/35 Singapore 189702 Tel: +65 9694 9704http://www.mysoundaffairs.com


X Audio - Entreq event on 14 January 2017

Frankie Pang, representative of Entreq Asia was in town recently to meet up with Entreq users. Frankie spent an afternoon at X-Audio, the Singapore dealer for Entreq, mingling with both Entreq customers and prospective ones.



I have been using Entreq products for a while now, having owned and used the Minimus and Tellus grounding box (together with Eartha Silver grounding cables) for a few years now. I did a review on the Olympus Ground Box, Tellus and Eartha Silver grounding cables (click here for the Olympus Review, and here for the Tellus / Eartha review).

Frankie shared with me information on some new products, in particular the K2, Everest and Tellus 2.

The K2 and Everest are upgrades available to any Entreq grounding box user - you simply need to replace one or more of the binding posts with either the K2 or Everest. Frankie was confident that the use of either could significantly improve the performance of the ground box in question. He suggested that using one or two pieces should give the most significant gains.

Frankie explained that the K2 uses a basic alloy of metals, while the Everest utilises a more complex composition. According to Entreq, the addition of a K2 or Everest to the Minimus ground box (which has a single binding post), would allow it to outperform a Silver Minimum. 



Moving on to the Tellus II, this is a significant redesign of the original Tellus grounding box, and is in fact three grounding boxes in a single case - a Silver Minimus for the right and left binding posts, and a Silver Minimus and Atlantis Minimum for the centre binding post. Unlike the original Tellus, all three binding posts for the Tellus II are electrically isolated from one another.

I left the event with a K2 and Everest for experimentation. Stay tuned for the results !

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