Specification
Price: £385
Medical grade Silicone
Full shell (can request different)
Dual driver balanced armature
1.4m non removable cable. Kevlar reinforced clear cable.
Ear impressions and Otoscopy included – Hidden hearing audiologists 
Colour/etching options (£10 extra each)
 
 
I’ve had this IEM for a year now.
I think it’s time to share my thoughts, starting from the beginning.  
 
Background
I wanted the ultimate commuting headphone. Over the ear closed backs didn’t float my boat for many reasons. Universal iem’s I’d been using for many years but these were getting annoying. I could only find comfort with a shallow fit, having tried pretty much every tip on the market with over 50 iem’s. Isolation was always lacking and with this shallow fit they would too often slip out of my ears.
Thankfully, I found what I was looking for (and more!) with the Minerva performer pro. 
 
I’d read a lot about CIEM’s and what they offer. And through having a few silicone custom earplugs I already knew about the ear molding process and what to expect comfort wise with the product after.
A few things that I was looking out for before purchasing;
 
- UK based + Experienced manufacture
Could have been mainland Europe if not the UK. But to avoid excessive shipping fees, VAT, customs and time delays, closer to home made more sense. Customer service was always going to be important with a product like this as was the manufacturers experience in making custom products; build quality and comfort were high priority.
 
- Silicon rather than acrylic
On the subject of comfort, the Mi-Performer Pro has a slightly higher shore rating compared to others out there, including my silicon earplugs. Whilst this means they’re slightly less flexible, there’s less friction enhancing comfort in my experience.
 
- Inclusive of audiologist ear impressions
Minerva have a strong relationship with Hidden hearing UK, a branch of audiologists found pretty much all over the place. You select one of over 75 of these branches and Minerva arrange the appointment for you; though you can arrange it yourself if you wanted.
Interestingly, you can stay on hidden hearings database and take advantage of their free hearing tests / otoscopies. I went to one recently (Piccadilly, London) and was surprised by really impressive facilities.
 
Anyway, since this was my first CIEM, I also didn’t want to overspend. Overall £350 for everything including delivery turned out to be very good value.
 
 
Process
Two step standard procedure. Around two weeks each.
1) Place the order and book with audiologists who form an impression of your outer/inner ear.
2) Audiologists send this to Minerva who convert it into an earphone, sending it to you via post. 
 
Again, some pointers.
- Earwax 
The audiologist at the time of impression taking will carry out an otoscopy which will include checking for earwax. They can advise further action to take if there’s too much wax for taking safe impressions. Some people get it checked from a GP beforehand or know enough to see to it themselves.
 
- Full mould including outer ear 
Normally okay, but you may want to remind the audiologist to take the mould past the second bend of the ear canal, and to also include regions such as the upper helix and others of the outer ear.
 
- Moving and duration of mould setting.
With hidden hearing the putty takes ~10mins to set, during which you should remain as still as possible. It’s up to you which jaw position you choose – open, closed, bite block, or a combination. Minerva’s customer service is great with very fast responses – their advice would be the best if you’re unsure.
Of course, it’s also up to you how slumped you are (back position) and other ways of positioning yourself such that the inner ear shape changes. I’d go for a neutral position, one that replicates how you would normally listen to iem’s when seated.
 
Remember, the shape of the mould will be slightly different to the silicone IEM body. The latter will be more comfortable, less extended and can be notably less in physical volume. Personally I needed the body to be half way between full and half shell, but still the point remains - mold is very important to final comfort and sound.
For someone new to custom in ear products, it may take around 1 or 2 weeks to get used to the fit, but otherwise it should be comfortable from the start.
 
 
Comfort/build quality
 

 
Obviously it’s a well done for build quality, but as these guys are very experienced with massive resource as a company, I wasn’t settling for anything less.
I took these pictured after a month of use, so naturally the silicone shows a touch less clarity. 
 
Overall the performer pro's are extremely comfortable earphones. 6hrs a day no problem, every day, months on end. Almost like an external body organ!
Comfort is a major plus point of these IEM’s which I’ll talk more on later.
 

 
Something else very important to build and comfort – the cable.
This cable is majestic. My favourite cable I’ve come across from all earphones/headphones. It’s fully smooth, fully supple along its entire length which is an ideal 1.4m. The reinforced wire section near the earpieces is completely integrated and goes undetected (no annoying stiff memory). The cable is not prone to tangling and catching onto clothing. Even the Y split is ideal in its position as is the cable cench and operation. And the L shaped jack is made really well too, being light, unobtrusive and allowing good flexibility.
It may seem like I’m going over the top but if you use an IEM all year long, it really makes a difference.
 
 
Sound
Okay, now the sound. Or maybe this is the first (and only) thing you’ll read..!
Put simply, the sound quality is beyond what I expected and my expectations were not low.
 
It's the only CIEM I’ve had, so I’ll relax a little on direct headphone comparisons. Just how I find the sound in general is good enough I think.
 
- Bass
Very good definition and balance. It's not a bassy headphone so for some tastes the bass at ~60hz may be lacking. In soundtracks for instance some people may want more. I don't like bass shy headphones that also present notes with thin body - miss out on the emotion of sound. This Minerva fares well in this regard though, where notes have plenty of meat and natural quality to make things sound heavy enough. You’ll feel the gravity of bass drums in orchestras and will receive a decent bass experience from complex rock compositions rather than drowning in a sea of lingering high frequency sound.
 
- Mids
Overall I'd describe this earphone as mid-centric, with a touch of elevation in the upper mids (~4khz). Actually it's more noticable since the highs are far from accentuated. Notes sound thick and plentiful, presented with a satisfying timbre. I have heard headphones better in portraying natural sounds, but not in the universal IEM world though. In other words it's a plus point of this headphone. Detail is high across the board as well as instrument separation, .  
 
- Highs
If 10 is the brightest high end headphone and 1 is the darkest, I’ll give it a 4.
Long term listening fatigue doesn't really occur with the minerva. That's for me anyway, but I suspect there will be those who want something brighter especially if it’s something they’re used to.
The Mi-Performer pro is extremely forgiving and smooth in the highs, the opposite of grating and punishing, making it great for listening to a variety of material. So whilst for example the sig pro would sound untolerable with a distortion suffering track, with the Minerva it’ll probably be listenable. You’ll still know it’s a poor recording but just won’t care as much.
 
- Presentation
Here is where I’ve seen the largest acoustic difference from universals. There’s definitely less congestion in the soundstage, thanks to a black background and well spaced out presentation. The soundstage benefits from more lateral extension, behind/in front of the head soundstage which overall surpasses all I've come across in the universal iem world; PFE 232, IE800, Shure 535, GR10...and so on. Needless to say, I prefer the overall sound of the minerva over all of them too, for many reasons. It just outsmarts them pretty much across the board in my opinion. But to those with customs, you probably expected me to say that!
 
- Different Sources
I’ve tried this earphone out of more sources than I can remember. It is of course sensitive but thankfully not particularly hiss prone; connecting to a standard smartphone should be okay. 
Notably, not much changes when swapping between ‘good enough’ sources. A poor source will make this sound as such, but above for example the HTC one M8 (slightly modified), there’s not much to be gained IMO. True, from an AK240 it sounds better but not near enough to warrant a purchase for me. You might want to use it with a desktop setup, but make sure your amp volume dial caters for sensitive headphones.
 
 
Over a year
A year makes a difference. You evaluate things differently, especially with respect to 'other than sound' features.
 
- Isolation
The Minerva has been my most favourite headphone over the year and isolation is one of the main reasons why.
This level of seamless comfort, sound and isolation transformed the worst part of my general day into something easily tolerable. Daily commuting in London with harsh annoying noises ensued in headaches and it's difficult to emphasize enough the difference this CIEM has made. 
 
It's as if you take your world with you, yet have very decent control over outside volumes. A lot of people worry about being dangerously oblivious to the world outside but much is dependent on the playback volume IMO. These IEMs without music playing isolate around 20db. Now if you pump up the volume and achieve an effective isolation of 50db+, you've made your choice. But with CIEM base isolation so high, little extra volume is needed for enjoyable listening. And at such levels train announcements, police sirens, traffic and even decent volume conversations are all audible. Actually pretty much everything to some degree apart from the quiet stuff.     
 
- Reliability
The Mi performer pro is extremely well built, definitely the cable section too. No hint of a problem with this hard wired cable. Remember though, It's a custom balanced armature earphone so you've to take care of it as standard. I had one problem with moisture damage to the RHS, around 8 months in. Minerva's customer service is very good so it was fine - but I did eventually need new impressions for a new build. 
 
- Complementary headphones
Maybe this is something important only to those with steady headphone collections. So headphones that their ears are well accustomed to, where a newcomer might find it hard to fit in. Sometimes an IEM with a strong signature can make the sound from your other headphones a bit weird. Because of it's largely neutral signature the Mi-performer pro avoids this. Actually not only does it fit in, but shines in its own way, never really giving the feeling of ‘I’ve missed out’ when switching over to full size reference headphones.
 
 
Conclusion
If you're considering CIEM's I fully recommend to go for it.
This particular one has been useful to me beyond expectation having completely changed the way I listen on the move.
CIEM's are not your average purchase and it does take time and effort in getting there. But for me, definitely, it was worth it in the end.

Sennheiser Orpheus - Demo Impressions
 
Last week I had the pleasure of demoing this legendary headphone system.
I found it to be a great experience so thought I might as well share it with you.                                                                                                                                                            
 
This pair is one that Senneheiser own themselves and had bought it down for a few days to audio lounge, central London. It’s in exquisite condition and I listened to it in a perfect environment – a quiet demo room for over an hour with my own music I’m extremely familiar with.
 
You might be thinking how I randomly stumbled on an Orpheus and so you should be as it was, well, quite random. Just the other week I was wondering around on a lunch break and walked to the end of Wigmore street (near Selfridges) to find a sweet looking high end audio shop that has a decent headphone contingent too. Wanting to demo the sr009, but with stax a bit short of energisers, the sales person, Arif, got in touch later asking if an Orpheus demo would peak my interest instead (!). He’s very open and knowledgeable mind you – he used to officially trade these units up till the very last one.    
 
 
 
Before Sound
 
HEV90
I’m sure you don’t need me to convince you on its looks.
 

 
 
Have you any equipment in your house that looks better?
If I had one I’ll give it a room to itself. I might want to switch it on once in a while too. When you do, there’s a little red LED that lights up and reflects nicely off the aluminium surfaces. I like the gentle way the tubes light up too, making for an even more sophisticated look.  
 
One thing I frequently moan about on headphone amps is the volume dial. I’ve sensitive hearing where lower volumes are more than enough and thankfully HEV90’s volume dial was perfect, allowing for plenty of movement without channel imbalance in the lower dB ranges. Neat.
 
 
Headphone comfort
Headphone comfort was so seriously high. I’m talking stock d7k levels or higher here. When taking them off after wearing them for over an hour, the first thing that hit me was how freakishly comfortable they were. The headphone is rather light, clamping force low and pads really soft/supple. Also to note – with this pair no material residue was left on my ears (unlike the he90’s I tried at last year’s London headfi meet).
 
 
 
Sound
 
Imaging / Soundscape
The soundstage is large (<HD800 though) and very multidirectional. It’s utilisation of space, layering and instrument positioning is outright the best I’ve ever heard. There’s a real quality in its deployment here making it hard not to be impressed by it with whatever you listen to. This was especially the case in complex music such as Lorne Balfe’s Assassins creed OST or Thomas Bergersen’s dreamaker where complexion was uncovered in almost an unfamiliar way. These orchestra’s felt like they simply came alive and provided a convincingly clearer picture of composition by component than any of my headphones have. 
 
 
Tone / Timbre
Full of body and just ohh so easy to listen to! 
It’s closest to the HD650’s I’d say in each notes weight whilst similarly remaining tactile and agile. All to a better degree though. Diana Krall and Jennifer Warnes sounded realistic from this system, no doubt, and when the instrumental sections broke out the sense of realism only increased.
 
Just the other week I listened to Elias String Quartet perform Beethoven live, unamplified, down the street at Wigmore Hall (stunning venue and sound). Actually I regret not having a track or two on the demo CD but if I were to hear this live recording through the Orpheus, I imagine I’d be deeply impressed. It’s that kind of realistic warm ‘chamber’ type of feel this system gave me, which always remained free from upper mid-range/high frequency brightness that I’ve heard from many TOTL headphones of today.
 
 
Sub Bass
Let’s be blunt - sub-bass performance left a bit to be desired. Soundtracks and Orchestral music (such as Hans Zimmer’s Rush and Thomas Bergersen’s Dream-maker) especially were calling out for more ‘rumble’ in the lows. A well driven hd800 provides this for example. Cello’s and strings didn’t reveal <60hz information across many of my sample tracks as I would expect a world class headphone to do so.
In terms of other bass properties - mid bass impact, speed, attack, decay, accuracy, timing and general quantity – things were very well done.
 
 
Brightness / Warmth
Really interesting this. The headphone extends high and reveals treble detail, but in a different way to ‘bright’ cans. I guess it feels relaxed and in a sense more calmly executed but when called for definitely does it deliver.  Take a track that is very treble centric; Evanescence – taking over me. Through the Orpheus this sounded outright remarkable with treble performance contributing in no small way. Cymbals were crashing and the electric guitar screaming with a stunning sense of realism of the like no headphone has hit me with.  This isn’t the best recording in the world, making it even more striking how awesomely the Orpheus delivered this track.
 
Perhaps on the other end of the scale was how music from Ludovico Einaudi sounded.  I’m a massive Einaudi fan and ‘Experience’ is one of my favourite pieces – though I hastily have to admit it’s a slightly muddy recording. Obviously, the Orpheus was faithful but with this track I prefer a brighter headphone. The violin towards the end sounds more effervescent, fragile and sweeter with a beyer T1, contributing beautifully to the overall ambience.
 
 
Detail retrieval
It’s very detailed, but to be honest I was expecting a tiny bit more.
For example with Keiko Matsui and Jan Garbarek, notes sounded a touch too rounded for my liking. I’d say this is less resolving in this way than a HD800 / T1, which reproduce the saxophones in both tracks more vividly and with better micro detail. It’s probably a cliché where one headphone is said to be for pure listening pleasure rather than a studio tool, but I would say the HE90 is an ultimate headphone of the former type.
 
Detail isn’t constantly thrown at you making long sessions appreciably less fatiguing. There were those few instances where I was expecting a little extra definition with individual notes across a few tracks. Don’t get me wrong, it was always clear, transparent, agile and fast, but there was detail in say vocalists breath and plucks of strings that I felt wasn’t presented at least with enough vigour. I guess this and sub bass performance were the two negatives I found with the Orpheus .
 
 
 
Overall
 
Thanks again to Arif at audio lounge for inviting me to this demo. A really enjoyable and interesting experience overall allowing me to hear extremely familiar music in a pleasantly different light. Let’s face it, I may never get to hear the Orpheus like this again let alone own one…..especially if I don’t find a spare £20k I wouldn’t do much else with.
 
 
 
Listening Setup
 
Setup
Power: Standard
CD Player/Dac: Bel Canto CD-2
RCA Interconnect: Siltech 550i
Amp: Sennheiser HEV90
Headphones: Sennheiser HE90
(forgot to check seriel #'s)
 
Listening conditions
Ambient noise: <~35db ambient noise
Ambient temp/humidity: Standard
Listening Volume: Low/Low-Normal
 
Music (Artist / Album / Track)
Ludovico Einaudi - In a Time Lapse - Experience
Agnes Obel - Aventine - The Curse
Lorne Balfe - Assassins Creed III (OST) - Main Theme
Diana Krall - The Girl In The Other Room - Black Crow
ATB - No Silence - Marrakech
Thomas Bergersen - Illusions - Dreammaker
Jennifer Warnes - Famous Blue Raincoat - First We Take Manhattan
Vivaldi Four Seasons (Chesky) - Vivaldi - Winter 1 Allegro Non Molto
Diana Navarro - La Esencia - Ea
Evanescence - Fallen - Taking Over Me
Hans Zimmer - Rush (OST) - Lost But Won
Jan Garbarek - Rites - Rites
Keiko Matsui - Glance of The Past - Bonfire In The Piano
Michael Jackson - HIStory Begins - Billie Jean
Riverside - Voices In My Head - Stuck Between
Yo Yo Ma (& Friends) - The Goat Rodeo Sessions - No One But You 

Two Smooth Solid State amps – Graham Slee UL Diamond and Burson Soloist SL
 
I’ve long been a fan of solid state amps, especially those with a small footprint. Both of these are ones with a smoother presentation, or as both manufacturers say in their product blurbs – ‘tube like.’
Both of these have had over 300hrs of burn in (the Slee's probably closer to 3000!) and both have impressed me but for different reasons making for an interesting comparison.
 
Burson Soloist SL £500
Little brother to the Burson Soloist. Analogue volume control rather than a stepped attenuator and slightly less power.
 
Graham Slee Ultra Linear Diamond Edition £615
Top of the range model from Graham Slee. This is designed to facilitate highly sensitive headphones more so than others in the Slee lineup.
 
 

 
 
Contents
1. Function and Usage
 
2. Sound comparison. (T1, D7k, Ultrasone Sig Pro....)
 
3. Listening Setup
 
 
 
1. Function and Usage
 
1.1 Graham Slee UL Diamond
 
This thing is small. The footprint is awesome actually which is supported well with the physical build quality. It’s not heavy at all yet stays firmly seated on the desk even when tugged by the T1’s heavy cable.
 
The volume control is very well done. It’s firm with the right amount of resistance to turning and friction on the dial. To me this is quite important for saving my hearing when the dial turns up by accident, say after I brush against it with my sleeve or something (recollection from using the Fiio E9 – excellent amp SQ wise I still think)
 
It’s £600 so you expect it to be well made and with good jacks/connectors/dials. I like the lowly lit green LED that’s on when it’s powered. Mind you, on the subject of power you might like the big and weighty PSU especially as it doesn’t require a kettle/figure 8 connection to the amp. Small amp, small unobtrusive simple AC connector (don’t know the size of the tip) but beefy, out of the way, PSU.
 
Switiching between source is well done here as well. Middle selected denotes off and up/down correspond to source1/2. I’ve had two sources at once connected and notice nothing weird going on, so it works well
 
All in all a nice looking small component that fits comfortably in a small rig (like mine)
 

 
 
1.2 Burson soloist SL
Much more weightier and larger than the Slee, but still not something I’d call big. It can sit next to my computer well enough.
 
The finish on this doesn’t look/feel as good as the slee - just running my hand over the plating and it’s not smooth. Anyway, it’s designed to be listened to more than it is to be physically stroked, so it’s not a problem.
 
I like how source switching is done with the press of a button where the LED’s have a lowish glow similar to the slee. The volume dial is very very good. Large with a nice weight, feel and resistance – better than the Slee. Really like this feature especially as it’s not a stepped attenuator which incidentally is what made me choose this over it’s bigger brother. I just can’t stand hearing them clicks through my headphones and as a result avoid all stepped attenuators.
 
 
 
 
2. Sound
 
2.1 Signatures
Each amp has it’s own kind of character (the burson more so than the slee), which I feel is demonstrated across headphones used in this test (Primary: Ultrasone sig pro, T1, D7k Secondary: mad dog, Ultrasone DJ, Fostex TH900)
 
The Slee feels like it’s about control and neutrality. The highs are smooth though very true to life it seems. This amp is very revealing of the source and when used with a warmer source the amp shows it in the bass and high range. Soundstage is on the smaller side, though instrument placement and separation is always excellent. It’s a close and intimate sound that's presented here which always seems to hold itself together well.
 
The Burson has much more of a sound signature (if I'm allowed to say that!). It’s more prominent and forceful than the slee which remains cool and almost understated in comparison. The main difference is that the burson injects a bit of fun into the sound; larger soundstage, more dynamic bass range, thicker, weightier bass/midrange notes and more smoothed out highs. I guess it makes the ultrasone sig pro’s sound more like the D7k’s than anything.
Compared to say a classic solid state, like the lehman black cube linear, the SL definitely has smoother highs and the same can be said when compared to the slee. It also sounds a fair bit ‘less’ detailed. I would't call this amp under-detailed but in terms of projecting micro details and resolution it can sometimes leave me searching. I’ll find them  when I look, but not otherwise. 
 
 

 
 
2.2 Headphone pairings                                                   
The Slee does well with headphones with a more recessed thicker midrange and ones that benefit from a slightly clearer presentation. Presentation where greater instrument separation is desired. Stuff like the D7k, TH900 and the T1’s do better with this than the burson especially because of their midrange where pushing back their midrange just doesn’t sound pleasant. These headphones have big enough soundstages anyway. In this regard the D7k/TH900 especially fit the bill, though I won’t say this slee is the best amp I've come across for them. The inbuilt one on the Beresford bushmaster and a musical fidelity M1HPAP both sound better as what they do is simply wake up the TH900. It’s better than the burson though which puts it even more to sleep!
 
The Burson likes headphones that are detailed but in want of a larger soundstage and a more cosier, smoother portrayal. Ultrasone Signature pro’s work really well with these as there’s a significant increase in soundstage warmth, weight and grandure compared to the Slee. The edges are more rounded but this ultrasone responds well to it despite the highs not being tizzy/sharp to begin with. Actually, this amp/headphone match is a downright awesome one. Talk about synergy huh?  
From what I've just said you can extract that the Soloist SL is a warm sounding amp but i'd like to warn against thinking it won’t pair well with warm sounding headphones. Mad dog’s simply sound better from this amp which although may be down to planars pairing better, does prove a point. It just feels like the thick bass is maintained and we benefit from the grander sound across all dimensions. 
p.s. I use the low gain settings by the way – don’t hear a difference between this and higher gain.
 
 
2.3 Summary
Slee over the Burson
Intimate and controlled, detailed sound.
More neutral than the Burson.
Shimmer on female vocals shines through unsupressed
When thinner than thicker vocals are preferred
More air around instruments
Slightly more Prat. Faster projection
More upfron, un-recessed midrange,
The bass range is better defined. It never sounds as it if lacks detailed – a highly detailed overall amp.
 
Burson over the Slee
Larger soundstage height and width
Dynamic and impressive sound
Warmth though not without slight undue accentuations
Warmer projection like in a cosy large scale concert, shining through on OST music.
 
 
 
3. Setup
 
3.1 Testing equipment
Power: Clearer audio copper line alpha power conditioner
Transport: acer s3 (128gb samsung 840 ssd, 4gb ram, i5, W7, Silenced Fan) & Dell Vostro 1500 (128gb kingston ssd, 4gb ram, core 2 duo, custom XP, usb hub)
USB cables: Belkin, Chord silver plus
DAC's: Arcam r-dac, Musical fidelity vdacII, Beresford Bushmaster TC7530
RCA cables: Chord Chameleon vee3, QED profile, Belkin, Mark Grant g1500hd,
 
3.2 Conditions
Ambient noise levels: Home listening : <<25db (Absolutely dead quiet. I mean it!). 
Humidity and temperature: maintained 21-23c and 50-60% relative humidity
Volume matching: using test tracks of different noise levels calibrate amplifier volume and perceived loudness with headphones. Conducted at every test.
Listening Volume: Extremely important to note. Some headphones prosper/fail at high/low volumes. I listen at low to low-normal listening levels. 
 
3.3 Albums
FLAC CD Quality files.
Variety of genres, with a sample being:
Riverside (prog rock), Within temptation (rock), Amethystium (New age), Secret Garden (Celtic), Lisa Gerrard (World), Armik (Spanish acoustic), Ah Ne Ma (Acoustic/world), ATB (chillout/trance), Tycho (Electro), Game (hip hop), MJ (pop), Yo Yo Ma (Classical), Hans Zimmer (OST), Diana Krall (Jazz) and the best out of them all... Ludovico Einaudi (Neo-Classical)

1. Introduction
Let me get straight to the point of why I'm writing my first and possibly only review of an item in the world of amps and dacs. This does not dissapoint in any way at all. That's unique.
 
In all the 20 amps or/and dacs there always is a bug somewhere. It's either a physical fault like it overheats, looses connection, comes with badly built ports, dodgy over-sensitive volume pot, humming noises, made using cheap exterior materials and so on. Or it sounds and performs on a level of anything between abysmal to (thank god!) quite good. 
 
Not the musical fidelity vdacII. And it's this lack of problem areas that makes this review easy and short.
 
 
 
2. Setup
2.1 Burn in
Please burn this in for 300hrs. If this is something that turns you away, then that's up to you. Pretty much everyone from the manufacturer to high street sellers to amazon reviewers to professional magazines and to headfi (i.e everyone under the sun) recommends a burn in for the sake of SQ.  
I can only repeat the message. Burn in definitely helps. 
 
2.2 AC adaptor
It's pretty much the first thing I read about when researching this dac- the provided ac adaptor sucks. It's output at a fixed 12v is 500mah. Of course, that's not going to be good enough and an external PSU from a high street electronics shop, or elsewhere, would be an ideal no fuss replacement. I'm using one outputing at 1700mah, which is ideal for this sort of thing. Heck, even my crappy tiny toyish usb hub comes with a more beefy PSU than the stock vdac one! 
 
You don't need to freak out when it comes to buying something like this. If you don't want to add bulk to the setup then do what I did and stick to the popular switched mode power supply (output tips of 1.35mm or thereabouts head fits into the vdac). Make sure the polarity is correctly addressed as with setting the voltage to 12v. Better safe then sorry.
Or if you want something bigger, maybe better, then a fat linear power supply is what you will look for. I'm not interested.
 
2.3 Connections
The input is of digital audio via toslink/optical/usb connections. Output is through a single twin rca (phono) connection. I use it mainly through USB which hasn't been skimped at all in this device. It works perfectly well and the manufacturers are keen to emphasise that this is where it's main quality lies- the asynchronous usb implementation.
A good enough range of connections? Agree??
Oh, and incase your wandering, over usb I've never experienced any technical problems at all.
 
2.4 Design
A dashing all brushed metal silver casing, nice. There's writing on the top that adds to the 'high class' type of image it seeks to create. Dimension wise its slightly wider than the fiio e9 but its slightly shorter too. Not too big or small.
I have to mention a slight negative here- the rca connection is at one side with the digital input connections all on the other. You find a similar thing going down with the hrt music streamers so it's not a rareity or an issue. But this knocks down a star in the design front.
 
 
 
3. Sound
3.1 In the world of dacs
What's to say other than- brilliant!
I've used it with a host of amps and that's my conclusion.
 
It's better than both the hrt music streamers II and the II+ in basic areas such as resolution. Individual notes on the vdac are presented with more body, clariy, definition and fullness. The soundstage is slightly bigger on the vdac too, as is the overall presentation. It's definitely more dynamic than either of these hrt's and it bests out all the other dac's I have too in ways similar and further to these. 
Very importantly it manages to never enter the debate of thick vs thin notes, sharp vs tame highs, dark vs bright and so on. It fits into the middle of these things so often that it's uniquely a very commendable performer.
 
3.2 In the world of headphones
I'm going to stop there with the sound impressions of the vdac as I need to set something straight. The SQ differences that exist in the world of dacs are not that big to be honest In my experience. No, I'm not a believer in if it measures well then it's audibly perfect- and don't any of you dare come up with the 'subjective vs objective' arguments as they have become comical of late!
There are differences, I do volume match, I try to limit my subjection to bias (statistician element in me) and this is what I hear. Sometimes, yep, I've never been able to detect a SQ difference at all between two totally different dacs at two different prices, even with extended listening. But in other cases like here, the difference exists and it makes no effort in hiding itself. 
 
 
 
 
4. Conclusion
 I'm not a musical fidelity fanboy either- their vcan II sucks. It's got an awefully sensitive volume pot rendering the whole unit almost unfit to use. It sounds good (better than a fiio e9) but nothing special.
I'm not telling you to buy or avoid this dac. I'm neutral of course. But what I am saying is that when there's so much **** out there in the world of dac and amps, something decent sticks out like a shining star and deserves recognition. The musical fidelity vdacII is such an example. 
 
 
 
 
 
Disclaimer
All that I say is based on my experience, what I have listened to and how I have conducted my tests. Don't take this review personally as the only person to take it personally should be me....