Monday, March 14, 2011

Brief audition of the Usher BE-718 DMD with Calyx DAC and integrated amplifier

I am quite familiar with the original Usher BE-718 which uses a Beryllium alloy tweeter. The BE-718 and the X-718 that preceded it stirred up quite a lot of controversy, from its close resemblance to a certain other renowned manufacturer, to the Beryllium content (or lack thereof) of its tweeter dome.

Controversy notwithstanding, the BE-718 sounded great and I would have walked home with a pair if my amplifier had the power to drive it. Audio Basic had no issues driving it with their solid state amplifiers, but a quick hook up to a 30 watt per channel EL-34 push pull amplifier proved that these speakers really thrive on power.

Fast forwarding to the BE-718 DMD, I believe that the speaker is internally identical to the BE-718, with identical crossover points etc. Worldwide, dealers are offering the DMD tweeters to BE-718 owners as a drop-in upgrade. Local users should be aware that the domestic version is not the same as the U.S. version which sports a tweaked crossover with upgraded capacitors and internal wiring.

Driven by the Calyx DAC and integrated amplifier (100 watts per channel into 8 ohms), the BE-718 DMD sounds quite different from its Beryllium predecessor, primarily in the resolution of air and detail. The Beryllium tweeter is already quite extended and resolving, and the DMD tweeter is a further step in this direction.

Are either tweeters bright ? That depends on what you are coming from. I think they are fine and subjectively sound less bright than the Beryllium tweeters on my Focal Micro Utopia BE. Of course, a tweeter does not maketh the speaker.

On the low frequency front, the Usher has a fair amount of grunt and good low bass given its cabinet size. Bass lines are agile enough and the amount of bass should be just right for a standard Singapore sized HDB bedroom (3x4 meters).

Going up to the midrange, vocals are smooth although slightly dry. The upper midrange has a slight hardness to it and brass instruments seem more prominent compared to other speakers.

The high frequencies are the true star of this speaker, with speed, resolution and air that are truly impressive for the asking price of these speakers.

Subjectively, the Focal is a better speaker. It has more bass authority, a better midrange, and more resolving high frequencies. It also throws a bigger soundstage and can resolve front to back layering better than the Usher. The Focal also happens to be much more expensive than the Usher.

At its present promotion price, I think the Usher is an excellent buy (contact X-audio or Audio Basic directly for prices). Is it worth it for original BE-718 owners to upgrade to the DMD tweeter ? I think that it is a far more difficult proposition. The cost of the DMD tweeters as sold locally is substantial. Although the DMD tweeters sound better to my ears, I would not put that much a premium to it to justify the cost.

Last but not least, credit also goes to the Calyx duo. The Calyx DAC (24/192) offers world class resolution at affordable prices, while the Calyx integrated amp never ran out of steam, even at rather uncomfortable volume levels. The Calyx integrated amp also has a built-in DAC and USB input (24/96 only). Add a Mac Mini, Calyx integrated amp and the Usher, and you have a very nice system for around S$ 6,000. Now where were systems like this when I started out in hi-fi 20 years ago ?

Saturday, March 12, 2011

Shuguang KT-88Z Black Treasure Tubes

Shuguang's Black Treasure KT-88 tubes are being run-in on my Cary amp at the moment.

Visually striking, these tubes are classy. Launched to commemorate the 50th anniversary of Shuguang, the Black Treasure tubes are said to have 60 differences compared to their normal line. The most obvious is the black high polymer compound carbon coating inside.

Initial testing upon power up resulted in a loud crackling distortion that lasted about 2 seconds before disappearing one one channel. It never happened again, so I would not put too much into that.

Trawling the internet revealed user accounts of long tedious burn in (200-600 hours), with an accompanying roller coaster ride in quality in the process. It kinds of reminds me of my Mundorf Silver-in-oil burn-in experience.

Thankfully, the Black Treasure sounded quite good from the outset. With about 10 hours under their belt,  initial impressions are that of exquisite refinement and quietness. Compared to the Genalex re-issues that preceded them, the Black Treasures had less bass bloom, but a more refined midrange and treble. The Genalex has more prominent bass, with a fatter upper bass that gives music solidity and heft. The Black Treasure is arguably tighter and more controlled.

The Back Treasure really differentiates itself on the midrange and treble. Apart from its inky black background, the dynamic contrast, and low level resolution were world class. Holographic presentation of instruments and voices, and the accompanying acoustic space were superb. The only fly in the ointment was the extension and air of high frequencies. Compared to the Genalex, the Black Treasures sounded restrained, and simply unable to let go. The local dealer and another hi-fi friend assures me that this would disappear upon extended run-in.

The highs eventually opened up. There was no "ah-ha" moment where the dark clouds parted, and the sun shone down on my humble abode. Rather, there was a slow and progressive opening up of the sound, with everything coming together quite well at about the 50 hour mark.

I checked the tubes every few weeks, and bias remained spot on. Sadly, one tube died on me after about a year of use (approximately 300 hours of usage).

Oh yes, please peel of the stickers affixed to the base of the tubes. They will drop off at the most inconvenient moment possible, and if you are really unlucky, fall inside your amp, or on some hot component. Across the six Treasure Tubes I used (from two different batches), I can guarantee you that this will happen as a matter of certainty.

Black Treasure tubes are available in Singapore from Live Acoustics,

Highly recommended.

Tuesday, March 1, 2011

DIY Power Distributor

No money for fancy power distributors ? Why not make your own ?

I saw a very nice solid aluminum power distributor casing in one of our local electronics surplus stores. It certainly could not be considered as refined, but was made from solid 5 mm thick sheets and had nice cut out holes for US sockets and an IEC inlet.

Choose your favourite sockets and your internal cabling of choice, and you are ready to go.

In my case, I used the following :-

1 x Oyaide SWO-XXX AC outlet

1 x Hubbell 8300 Hospital Grade AC outlet

1 x Hubbell 5362i AC outlet

1 x IEGO gold plated IEC inlet

Neotech 12 AWG PC-OCC teflon insulated solid core copper wire

Raw materials before assembly. 

Fit and finish is a bit rough

Close-up of the Iego IEC gold plated inlet. Silver plated o-ring terminals are provided.

You can also put in your choice of damping material, e.g. Fo.q, bitumen sheets. Feel free to put in other stuff like AC line filters (X-rated capacitors only please and make sure that your leads are well insulated !). For the new age guys, put in your crystals of choice.

There you have it – a nice and high quality distributor for not too much money.

Ground wires all terminate on the earth screw of the first AC receptacle

The bent Neotech cables. A good work out ! Getting the right length is absolute critical.

Dry fit

Finished product !

Any practical tips ? If I had another go at this, I would use either multi-stranded copper wire or multiple runs of a smaller gauge wire. The 12 AWG is stiff as hell. Needless to say, please check your wiring for continuity and shorts using a multimeter before connecting it to the mains.

Based on my daisy chain wiring, the first set of receptacles would sound the best. Wiring the receptacles in parallel would have been difficult and probably require me to change to thinner cables to terminate properly at the IEC inlet.

Also, the screws provided on this casing are absolutely useless and deform at the slightest pressure. All screws and hex nuts were changed to stainless steel type.

The outlets of the Hubbell are connected together via a thin metal bridge (to facilitate snap off in case of split voltage wiring needs). I suppose breaking off the metal bridge and using a copper wire would improve the sound a bit.

Total cost if you used Hubbell outlets  and Neotech copper wire would be about USD 160. If you were feeling rich, you could use the Oyaide R-1 (which I use in an Oyaide MTB-6 used in my main system) and solid silver wiring.

Where should you spend your money ?

I compared this to my Oyaide MTS-6, which is a basic model distributor, with unplated Oyaide AC receptacles, and copper wiring, as well as my Oyaide MTB-6 which is made from thicker metal and has solid silver wiring. Both my MTS-6 and MTB-6 have identical receptacles, the R-1 and SWO-XXX.

The MTS-6 was noticeable inferior to my DIY distributor, while the MTB-6 has no difficulty surpassing it.

Given a budget, I would spend most of the money on a quality and heavy chassis, followed by the choice of receptacles, and lastly the internal wiring. Despite the high performance of the R1, it was simply unable to perform in the MTS-6.

Happy DIYing ! An important disclaimer, if you have no idea what you are doing, please buy a commercial product. We are dealing with lethal voltages here.