Wednesday, February 7, 2007


since it's gonna be sold to the public in a week's time, guess it would not hurt if there is some sneak peek.

so, here's the nokia e65 dual phone for you...

very sleek phone that has quite a nice finish, slightly heavy feel, but i think that adds to giving an impression of a solid build. the colours are vivid and most importantly, you no longer have to shade the screen to see what is on it under direct sunlight... it is actually quite visible!

the only downside is that it is a battery sucker... 10 mins on the phone and the battery is real hot. handsfree kit usage is most recommended... don't want a battery that blows up next to you right?

the navigation key pad takes some getting use to, but should be ok if you use your nails to push the keys. keypad has less than usual tactile feel... which i thought was not too nice a feature... i personally prefer keys with some feedback... at least i do not need to look at the screen to know that my key strokes are really entered in a short message creation.

there was one night when having the wifi and voip turned on and the phone was flat in the morning... the voip quality, at least in singapore (mio mobile), was actually surprisingly good. there is a little lag time from when a person speaks till when you hear the actual voice, but this is not apparent unless the person is right in front of you... that is when you can actually see the mismatch between the lips and the voice via the ear piece. but free outgoing calls in the hotspots or home wifi to local numbers is a difficult deal to beat... and apparently it works in some countries too... as long as session initiation protocol is not blocked by the ISP.

more photos here, and here, and here, and here....

Tuesday, February 6, 2007

5687 preamp done...

and it's about time... since the holidays are well over and work has taken on the 4th gear. :P

an idea for a preamp that started off as a transformer volume controller, to a dht preamp, and finally to a noval indirectly heated preamp with output transformer.

and it turned out that i built the 5687 preamp with LED biasing and tamura A4714 output transformer. all these is with parts that are on hand... mostly...

even the chassis is made from aluminium that are lying around for some forgotten project... just so happens that the width of the aluminum plates are 10mm longer than the width of the A4714, making it a suitable candidate for a tower chassis... and so it is. for an easy chassis build, i got 2 MDF to be the front and back of the preamp. the pesky thing about 3/4" thick MDF is that it is a hassle to make a hole for any connector thru it...

the 5687 was wired as double sections to lower the plate impedance so that it will better leverage the 5k output transformer. heaters are in series, fed by 50000uF of elna capacitors and 2 paralleled LM317 set up for 830mA current regulation each. this gave around 11vdc. a little low as i used a common 1R5 coffin resistor for the LM317. maybe i should series a 1R and a R47 to achieve higher output current... but well... i have not known anyone who used tubes till they die of cathode poisoning... plus i used raytheon 5687wb and not the super expensive bendix 6900... so what the heck...

rca plugs for the input selectors are actually stripped from my neutrik rca from the m10 project. the output plugs were from canera rcas. volume pot is a 100k blue alps. signal wires are silver upocc wires, copper hook up are upocc copper wires, umbilical are multistrand 14ga upocc copper. all wires from ahfartaudio. in fact, my drd used all upocc wires internally. silver was used for signal path.

power supply portion was built on a hammond chassis meant for another forgotten project, using some handsome irons from nick chua. it is rectified by the rca 83 mercury vapor full wave rectifier, two 50H chokes and many 220uF philips capacitors.

future mods would be to add the constant current source that i implemently wrongly... which led to a loud bang upon power up, with bits of the transistor flying out. hahaha... ;)

here's a flickr set of the preamp.

Thursday, February 1, 2007

work and the audio lover

it just dawned on me that in my job history, i know of only one other audio lover in each one of the company which i worked for (at least in singapore context... well, i only know of one other audio guy when i was in US too...). is this a strange coincidence or are audio lovers/audiophiles a rare breed?

just look at the amount of messages flooding a local photo forum as compared to a local audio forum... perhaps audio is passé... the crowd has flocked to digital photography.

a colleague was remarking that there are more and more amatuer photographers moving into wedding photography as a sideline to bring in additional cash. digital photography has lowered the barrier to entry so much that anyone with 1 or 2 years of digital photography experience will dare to take on a wedding shoot. this is perhaps unheard of when analogue was king.

who would have dared to take a risk of shooting on film, a chinese wedding dinner, without knowing that the shots are nothing less than perfect? what happens if the film leader was not loaded correctly into the spool?

perhaps with the influx of class d or class t amplifiers, the audio scene will be much revived?

who would have taken a serious look at B and O when they have those lifestyle speakers and amplifiers? take a look today and people would be asking if an amp is ICEpowered.

so, how many audio friends do you have at your workplace?