KMS' Sapphire Headphone Amplifier

This is a Single Ended, Solid State headphone amplifier, built by a person located in India, who, if I am not wrong, is an engineer by profession and builds amps and other audio related DIY projects in his spare time. The last I heard, the price for a new unit was roughly $500 (~Rs.35,000). It has a single pair of Single Ended RCA inputs and a single 6.3mm headphone out. A local friend owns one and I have tried it a couple of times fed by my Bifrost2. The Bifrost2, while I love it on speakers, I just don’t like how it sounds on headphones. So it wasn’t until yesterday, when I tried the Sapphire with the Phi Deca DAC, was I able to get a better read of the amp’s sound characteristics and performance.

The overall tone of the amp is on the neutral side, with sufficient body in the midrange and, most importantly, it is free of any treble nasties. As a result, it pairs well with both the HD650, as well as the HD800. It is a fairly transparent amp, so the DAC in the chain can have a significant influence on the sound. For reference, I can’t listen to this amp when fed by the Bf2, as the Bf2 can be quite incisive and edgy sounding in the treble, and I have found this phenomena to be more severe on Sennheisers and other dynamic drivers, than planar headphones.

Transients and attacks are not as rounded as BW2 or Lyr3, and will be once again will mostly take on the character of the DAC. The macro and micro dynamics performance may be a touch better on the BW2, but I will need to hear both the amps again side-by-side to say for sure. Without a doubt, the BW2 pulls ahead in the headstage and bass authority. While the Sapphire doesn’t hit softly like the Lyr3, it doesn’t have the authority like that of the BW2 or the Mjolnir2. But the Sapphire has a slightly cleaner bass and does bass textures slightly better than the BW2 and also has a slightly more transparent and clearer midrange. In terms of overall performance, separation, resolution and detail retrieval, it may be a small step behind the BW2 and perhaps in the same ball park as the Lyr3 and the Mjolnir2.

For the asking price of roughy $600, this is a fantastic amp. Especially for the folks located in India, where good desktop audio gear can be stupid expensive to obtain, the Sapphire is a very compelling option for anyone looking for a well rounded desktop amp that can work with both dynamic and planar headphones. Just make sure you feed it with a DAC that fits your preference.

Equipment Used:
Sources: Allo Digione (Coaxial), Hiby R6 (Coaxial), Macbook (USB)
DACs: Bifrost2, Phi Deca DAC, Cayin N5ii
Amps: EC BW2, Sapphire
Headphones: Modded 800, HD650, Hifiman Arya, Audeze LCDi4

 

@uniqusrname build is really good. Happy owner for couple of years. Waiting for his OTL amp which he himself has designed.

 

My impressions coincide with urs. A surprisingly clean and powerful Amp for its price. Been using it for a year now.

Chain is allo digione -- phi deca dac ( diy dac with Tda1387) -- sapphire-- hd600/hd800S/verum one/ Yamaha hp1 ( modded).

I found the Amp very transparent and neutral with a hint of kick in the bass. Nothing too exaggerated. No funky treble. The dac really dictates the sound. Has enough power to drive all the above mentioned hps to reasonable potential.

Lastly for the price. I have yet to find another Comercial Amp that I wud say is better.

@uniqusrname take a bow.