This will be my first Head-Fi review and the review samples have been kindly provided by Burson Audio. I had been testing quiet a few opamps and Burson Audio reached out and asked me would I like to test the new V5i Dual opamp. I said yes as I had always wanted to test the V5i's, I'll try keep this review short, sweet and straight to the point.
The Amplifier & Headphones
The DAC/Amp I used is relatively rare from what I have seen, it's the Matrix Audio M-Stage HPA 2C. It comes equipped with a linear power supply, a CS4398 DAC and an OPA2134 as the stock opamp. I have seen a few of the older HPA's for sale and the HPA 3U & 3B on Massdrop from time to time but I think this 2C model is somewhat overlooked. It can drive a T50RP to distorted levels at about 75% in high gain mode, it has more power than my NFB.11 (ES9018). Build quality and design are top notch.
The headphone used was a MK2 Modhouse Audio Argon with an extra wide deerskin strap and a ZMF Oval pads. The T50's are hard to drive and the Argons are one of the best T50 mods that have ever seen the light of day.
How it sounded before
The stock sound has very strong bass but a narrow sound-stage than say compared to the NFB.11 which has a lot of air and width but less bass. Depending on the track it can sometimes had a little harshness to it which at times became fatiguing which I believe was in the upper-mids.
This is what led me to testing different opamps. I tested the following LME48960, OP275, LM4562, NE5532 and I had settled on the OPA2604 which was an improvement over the stock OPA2134 to my ears and it made it a little smoother for long sessions.The changes weren't drastic but it was noticeable from chip to chip. In truth I was on the verge of selling the unit and I then had the opportunity to test the V5i-D.
The V5i is a good bit larger than the regular discrete opamps but it fit easily into the chassis of the HPA 2C. I personally think it looks cool and compliments the rest of the well laid out internals of the HPA 2C.
How it sounded after
Sound-stage and Imaging
The Argon is a wide headphone but even that felt narrow on this amp with thunderous bass. The narrow sound stage is now very wide and it has much more air which in turn means everything feels less compressed which I think was a big part of the harshness I mentioned earlier.
There is greater separation with instruments and imaging is improved. Everything can be heard with much more clarity. Where the NFB.11 sometimes feels a little loose, this has more focus and precision in it's delivery.
The bass isn't as overpowering as it was which sometimes detracted from the other frequency ranges. Don't get me wrong, it still has strong bass but it's much more clear and precise and does not bleed into the mids.
Mids & Highs
Due to the bass being cleaned up and widened sound-stage now all the instruments are very clear and very smooth. Any harshness has been obliterated and it almost sounds almost as smooth as my TA-10 tube amplifier with a NOS Mullard tube.
The highs are again smoother but it still has plenty of detail and minute sounds can be heard coming from many different directions due to the improved imaging. It's not overly treble happy and I am OK with that, everything is buttery smooth here.
I could go on about different tracks but it's improved across the board. Heavy Metal tracks sound great and not harsh in anyway. EDM is very clean and tight and Instrumentals are a joy to listen to.
The highs might be a little laid back for some where this really shines is with the improved sound-stage, imaging and silky smooth mid range. It's a music lovers delight and it's borderline tube like.
To me this amp needed fixing and by the power of the audio Gods this opamp does what the others could not do. So If you own an M-Stage in any of it's flavors be that the older model, 2C or 3U this little chrome marvel is for you it will literally transform the sound profile, in short it's amazing and a must buy!
This pairing is so good I think Matrix Audio should actually offer this as an a option with the 2C as it is now my favorite amp which might I add was just about to sell, in fact this combination is better than my NFB.11.
You can buy a pair of V5i Dual for $69 and one V5i Dual for $39, it is a bargain for the improvement it made in this case.
NOTE: I may add my TH-610 and a DAC-X6 to this review at some point, all views above were based on the M-Stage HPA-2C and MK2 Argons so your mileage may vary. I also have only about 20-30 hours of use on it so it may change over the coming weeks with a little burn in.