Messages

1

HiFi Audio Equipment Discussion / Re: Ethernet cable

« on: March 19, 2017, 03:03:32 PM »

i have tried several different LAN cables, mostly factory-terminated patch cord - Belden Cat6+, SANWA Cat 7, China-made Cat7 and Prismian Cat 6+. Each has its own merits. However, LAN cable inherently inject electrical noise from the switch to the DAC clock and chip. Optical isolation is quite an essential measure to filter off the noise. Some DACs such as North Star Design has in-built optical isolation chip such as Texas Instrument ISO7xxx series.

I have moved onto Aurender N100H music server which plays from a SSD cache, mainly because of Aurender's superb app and the reduced number of equipments in the system.   

2

HiFi Audio Equipment Discussion / Re: Isolation Platform

« on: March 19, 2017, 02:42:24 PM »

i bought three of the same chopping board from IKEA and they work great. Bamboo is a natural composite material with good damping effect. The IKEA board features bamboo plies sandwiched in 0 deg and 90 deg orientations. This configuration can help to spread out vibration force in different directions with minimum resonance, whereas a uniformly aligned grain pattern is more prone to induce resonance. I believe the performance of the board as an isolation platform be be further improved if IKEA adds two more 45 deg plies.

3

HiFi Audio Equipment Discussion / Re: HiFi visiting in Sarawak

« on: December 10, 2016, 08:02:10 PM »

Must write review on the food,too!

4

HiFi Audio Equipment Discussion / Re: Nordost,Cardas,Kimber,MIT, spk cable,I/C, PC electrical properties (L,C,R)

« on: December 09, 2016, 10:19:04 PM »

Need to pay test fee or not?

5

HiFi Audio Equipment Discussion / Re: using NAS to stream DSD file through Ethernet to Marantz NA11S1

« on: December 04, 2016, 10:21:09 PM »

Some observation from my recent NAS upgrade: it is advisable to use an entry-level NAS rather than a high-end model with many functions.

I recently bought an Asustor AS202T NAS with a Crucial 750G SSD to upgrade from my Buffalo LS421DE NAS (same one as jb's.) Using Asustor's system monitor, I found out that music streaming is a stressless job that requires very little hardware resources of the NAS. When streaming 44.1kHz/16bit WAV file, CPU utilisation (Intel ATOM 1.2Ghz) is only 1%, memory utilisation is 17% and network trafficis only around 200~250kb/s. Playing HD file increases network transfer to about 600kb/s to 1Mb/s, without adding to the CPU and memory load. So actually the NAS is idling most of the time.

I guess a high-end NAS with all the transcoding hardware and circuit will only inject more noise to the system.

6

HiFi Audio Equipment Discussion / Re: USB Audio

« on: December 04, 2016, 09:59:55 PM »

streaming audio data file through USB is not as simple as thought, as the PC clock and your network DAC clock has to be synchronize else you may have jitter data error. See the attachment file on how they implement USB audio streaming. Thus if you add any external clock it will improve sound quality, or a better USB cable that reduce interference noise also improve sound quality.

However if audio streaming is through a true asynchronous transmission, then clock timing is not that critical for data streaming. Guess they choose the easy way for consumer but not necessary best for audio.
 "In telecommunications, asynchronous communication is transmission of data, generally without the use of an external clock signal, where data can be transmitted intermittently rather than in a steady stream.[1] Any timing required to recover data from the communication symbols is encoded within the symbols. The most significant aspect of asynchronous communications is that data is not transmitted at regular intervals, thus making possible variable bit rate, and that the transmitter and receiver clock generators do not have to be exactly synchronized all the time."

Absolutely true. Clock precision plays a key role in DAC operation. Computer is designed to tolerate high jitter transfer, but ensure data integrity. However, this is bad for audio.

IMHO, products with match high-precision clocks, such as Auralic Aries media bridge and Auralic VEGA DAC whosie femoto clocks lock onto each other, or integrated server/NAS+DAC such as Aurender A10, are good designs because they solve the clock issue.

7

HiFi Audio Equipment Discussion / Re: ISSE 2016

« on: December 04, 2016, 09:46:18 PM »

Yamaha flagship speakers with Passlab amps.

The NS5000 demo was quite pity. The speakers showed silky smoothness, fast transient, good transparency and plenty of details, but they were not broken in and the bass was totally missing.