Finally a holiday that no need to go to work. Time to fix those broken things.
Recently, this blog started to get attention from spam robots. Time to enable the spam filter. Luckily, the blogging software that I use supports Akismet. Also took this opportunity to upgrade Ruby, Gems, Ruby on Rails, and the blogging software typo... what a better way to spend the whole afternoon... orz...
Still have some minor issues... e.g. the Atom feed is not working etc... will fix them later.
Friday, April 4, 2008
Tuesday, March 18, 2008
Monday, March 10, 2008
Be Strong
Be Strong - Delta Goodrem
Are you swimming upstream in oceans of blue? Do you feel like you're sinking? Are you sick of the rain after all you've been through? Well I know what you're thinking When you can't take it You can make it Sometime soon I know you'll see 'cause when your in you're darkest hour And all of the light just fades away When you're like a single flower whose colours have turned to shades of gray Well hang on and be strong We're taking each step one day at a time You can't loose your spirit Let live and let live forget and forgive It's all how you see it And just remember keep it together Don't you know you're never alone 'cause when you're in your darkest hour And all of the light just fades away When you're like a single flower whose colours have turned to shades of gray Well hang on, and be strong No you're not defeated And soon you'll be smiling once again Then you won't have to feel it Let it go with the wind Time passes us by And know that you're allowed to cry 'cause when you're in your darkest hour And all of the light just fades away When you're like a single flower whose colours have turned to shades of gray Well hang on and be strong
何處惹塵埃
煩~
上星期尾發現咸水喉入屋附近有水滲出黎。Weekend 叫左屋主上黎睇，拍板要整。隨即 call 師傅上黎。睇完一輪，又鑽左一輪。
最後發現水喉裂o既位置太深，係牆中間，所以要搭棚出去鋸左條喉，成條換。
星期一朝早九點幾兩個搭棚師傅就到左。唔洗一個鐘頭就搭好個棚。勁！
跟手兩個水喉師傅接力。一個係出面，一個係入面。又鋸又鑽，幾個鐘頭之後攪掂。之後等多幾個鐘等o的膠水乾。之後再開番大廈水制試過ok，師傅係六點幾o既時候終於可以收工。
最後成屋都係灰塵，又要抹抹抹抹抹… orz…
上星期尾發現咸水喉入屋附近有水滲出黎。Weekend 叫左屋主上黎睇，拍板要整。隨即 call 師傅上黎。睇完一輪，又鑽左一輪。
最後發現水喉裂o既位置太深，係牆中間，所以要搭棚出去鋸左條喉，成條換。
星期一朝早九點幾兩個搭棚師傅就到左。唔洗一個鐘頭就搭好個棚。勁！
跟手兩個水喉師傅接力。一個係出面，一個係入面。又鋸又鑽，幾個鐘頭之後攪掂。之後等多幾個鐘等o的膠水乾。之後再開番大廈水制試過ok，師傅係六點幾o既時候終於可以收工。
最後成屋都係灰塵，又要抹抹抹抹抹… orz…
Sunday, March 9, 2008
iPod mini mod
The microdrive in my first generation iPod mini finally died a few days ago.
The 1st gen iPod mini utilizes the same Wolfson Microelectronics WM8731L audio chipset as the 3rd gen iPod (which is believed to be the iPod with the best sound quality). The technical details can be found here.
Anyway, many people has tried to mod the 1st gen iPod mini to use flash based card. Now I have a good excuse to try it :P
First thing to do is to find the right compactflash card. The key word to look for here is "ATA compatibility". The speed of the card doesn't matter. The one that I used is from the A-Data Speedy series. Picked up the 16GB model for HKD520.
The rest is easy. Just follow the online tutorial to disassemble the iPod mini and replace the microdrive.
Finally, connect the iPod mini to a computer and use iTunes to restore the firmware. Restart. And iPod mini recognizes the card without any problem.
To do: replace the battery with a higher capacity one and reinstall the Rockbox firmware later to play FLAC.
The 1st gen iPod mini utilizes the same Wolfson Microelectronics WM8731L audio chipset as the 3rd gen iPod (which is believed to be the iPod with the best sound quality). The technical details can be found here.
Anyway, many people has tried to mod the 1st gen iPod mini to use flash based card. Now I have a good excuse to try it :P
First thing to do is to find the right compactflash card. The key word to look for here is "ATA compatibility". The speed of the card doesn't matter. The one that I used is from the A-Data Speedy series. Picked up the 16GB model for HKD520.
The rest is easy. Just follow the online tutorial to disassemble the iPod mini and replace the microdrive.
Finally, connect the iPod mini to a computer and use iTunes to restore the firmware. Restart. And iPod mini recognizes the card without any problem.
To do: replace the battery with a higher capacity one and reinstall the Rockbox firmware later to play FLAC.
Monday, March 3, 2008
PIMETA headamp
After reading my DAC post, some friends asked me what exactly is my "PIMETA headamp".
The PIMETA headamp is the box on the left.
Well, first of all, headamp is an amplifier for headphones. It takes the audio signal from the source, amplify it (can be both in terms of voltage and current), and drive the headphone.
This particular headamp that appeared with the DAC is a PIMETA that I built a few years ago. It is simple to built and tune.
Here is a peek inside.
The big blue box is an Alps volume control. The four red cylinders are Elna Cerafine capacitors. The little board on the side with yellow sockets is my DIY voltage regulator to provide clean power to the headamp.
A closer look.
I fitted this headamp with 6 x BUF634. BUF634s are buffers that provide enough current to drive the headphone. They also help to drive the headamp "deeper" into Class-A.
3 x AD843 op-amps provide the voltage amplification. Different op-amps have different sound signature. Op-amp swapping is the easiest way to tune and modify this headamp.
Close up on the op-amps. These 2 are for the left and right channels. The other OPA843 is on another socket for the ground channel.
The PIMETA headamp is the box on the left.
Well, first of all, headamp is an amplifier for headphones. It takes the audio signal from the source, amplify it (can be both in terms of voltage and current), and drive the headphone.
This particular headamp that appeared with the DAC is a PIMETA that I built a few years ago. It is simple to built and tune.
Here is a peek inside.
The big blue box is an Alps volume control. The four red cylinders are Elna Cerafine capacitors. The little board on the side with yellow sockets is my DIY voltage regulator to provide clean power to the headamp.
A closer look.
I fitted this headamp with 6 x BUF634. BUF634s are buffers that provide enough current to drive the headphone. They also help to drive the headamp "deeper" into Class-A.
3 x AD843 op-amps provide the voltage amplification. Different op-amps have different sound signature. Op-amp swapping is the easiest way to tune and modify this headamp.
Close up on the op-amps. These 2 are for the left and right channels. The other OPA843 is on another socket for the ground channel.
Saturday, February 16, 2008
DAC
Finally bite the bullet and got myself a DAC. Well, an USB DAC to be exact. (Anyway, my main concern is on the DAC part. The USB sound card in it is just a bonus :P)
It is the Mini USB DAC by HiFIidiy.net. Granted, it is not the best DAC out there. But given its price (< HKD900), it is tough to beat in its own class.
This DAC is based on the Texas Instrument PCM1793. And rumor said that the headphone amplifier part is a clone of the Solo.
But to my ears, my DIY PIMETA sounds much better that the built-in headamp.
On the left is my DIY PIMETA headphone amplifier, with Analog Devices AD843 op-amps installed. (If you love pop/vocal and is not a bass-head, I strongly recommend the AD843 op-amp. It might not has the details of the OPA627 / OPA637, but the tone produced by AD843 beats them all (even the OPA2111 that I have can't beat the AD843).
My current setup is: Pioneer DV-636D -> (S/PDIF) -> DAC -> PIMETA. The S/PDIF cable is a Canare cable. There were debates on the net that whether a RCA cable can really make a real 75 ohm coxial cable. But nevertheless, this Canare cable with the designed plugs seems to be doing fine... at least to my ears (These Canare plugs require a special crimp to assemble the cable... so I bought this interconnect directly from a studio shop).
The analog RCA interconnects are DIY ones made from Swiss Gotham GAC-1 cable with Canare plugs.
It is the Mini USB DAC by HiFIidiy.net. Granted, it is not the best DAC out there. But given its price (< HKD900), it is tough to beat in its own class.
This DAC is based on the Texas Instrument PCM1793. And rumor said that the headphone amplifier part is a clone of the Solo.
But to my ears, my DIY PIMETA sounds much better that the built-in headamp.
On the left is my DIY PIMETA headphone amplifier, with Analog Devices AD843 op-amps installed. (If you love pop/vocal and is not a bass-head, I strongly recommend the AD843 op-amp. It might not has the details of the OPA627 / OPA637, but the tone produced by AD843 beats them all (even the OPA2111 that I have can't beat the AD843).
My current setup is: Pioneer DV-636D -> (S/PDIF) -> DAC -> PIMETA. The S/PDIF cable is a Canare cable. There were debates on the net that whether a RCA cable can really make a real 75 ohm coxial cable. But nevertheless, this Canare cable with the designed plugs seems to be doing fine... at least to my ears (These Canare plugs require a special crimp to assemble the cable... so I bought this interconnect directly from a studio shop).
The analog RCA interconnects are DIY ones made from Swiss Gotham GAC-1 cable with Canare plugs.
Friday, February 15, 2008
Let's Start from Here - Joanna Wang 王若琳
By：Luke McMaster / Vincent Degiorgio / Damhnait Doyle giving up why should I have come too far to forget beautiful just got lost somewhere along the way so much was missing when you went away let's start from here lose the past change our minds we don′t need a finish line let's take this chance don’t think too deep all those promises we couldn't seem to keep I don't care where we go let's start from here standing here face to face a finger on your lips don't say a word don't make a sound silence surrounds us now even when you were gone I felt you everywhere let's start from here I've never been the one to open up but you've always been the voice within the only one for my cold heart let's start from here lose the past change our minds we don't need a finish line let's take this chance don’t think too deep and all those promises we couldn't seem to keep I don't care where we go let's start from here
Saturday, February 9, 2008
Two years
While doing a routine health check, I realized that one of my servers (that is running a hobby project from my friend and I) has been working non-stop for almost two years.
The server was assembled by me. A 3U rack mount chassis bought directory from factory (a real bargain!). Two redundant PSUs. An Intel dual sockets motherboard. Two 2.8GHz Xeon CPUs with hyper-threading. 2GB of RAM (yes... RAM was quite expensive at that time so that was what my friend and I could afford :P). Two sets of RAID: 2 x 80GB RAID 1 for OS and database, plus 8 x 200GB RAID 5 for application data.
I spent nearly a month on assembling the hardware and fine tuning the OS kernel (Linux) and RAID/DB/cache settings etc. Still can't forget the noise produced by the 2 PSU and 10 hard disks, especially when I had to do it in my bedroom and had the machine running 7x24 for stress tests!
Actually the server was up and running more than two years ago. But about six months after the server was deployed to the data center, one day it suddenly crashed. After a few hours of diagnostic, it was concluded that one of the SATA ports failed! And it took me another five to six hours to rebuilt the RAID, performed some tests and restarted the application.
The service was resume about two years ago around midnight. Luckily it has been running smoothly since then. This also means that I haven't been to the data center for two years! :P
The server was assembled by me. A 3U rack mount chassis bought directory from factory (a real bargain!). Two redundant PSUs. An Intel dual sockets motherboard. Two 2.8GHz Xeon CPUs with hyper-threading. 2GB of RAM (yes... RAM was quite expensive at that time so that was what my friend and I could afford :P). Two sets of RAID: 2 x 80GB RAID 1 for OS and database, plus 8 x 200GB RAID 5 for application data.
I spent nearly a month on assembling the hardware and fine tuning the OS kernel (Linux) and RAID/DB/cache settings etc. Still can't forget the noise produced by the 2 PSU and 10 hard disks, especially when I had to do it in my bedroom and had the machine running 7x24 for stress tests!
Actually the server was up and running more than two years ago. But about six months after the server was deployed to the data center, one day it suddenly crashed. After a few hours of diagnostic, it was concluded that one of the SATA ports failed! And it took me another five to six hours to rebuilt the RAID, performed some tests and restarted the application.
The service was resume about two years ago around midnight. Luckily it has been running smoothly since then. This also means that I haven't been to the data center for two years! :P
Sunday, February 3, 2008
男人的末日
各位男仕的末日到了！女人終於有辦法唔洗有男人都可以生育喇！
Death of the father: British scientists discover how to turn women's bone marrow into sperm
The only catch is... 只可以生女，因為女性本身冇 Y-chromosome …
…同生出來的 bb 有好大機會有 defects… -_-"
Death of the father: British scientists discover how to turn women's bone marrow into sperm
The only catch is... 只可以生女，因為女性本身冇 Y-chromosome …
…同生出來的 bb 有好大機會有 defects… -_-"
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