Not Shopping in Hong Kong

I'm done with my two-day on site work at our reference customer here in Hong Kong. Things did not go too well yesterday, but we were able to salvage decent (not stellar) performance today. So things are generally positive.

A friend of mine who works in Singapore said that Singapore is one huge shopping mall. If that's true, then Hong Kong is one colossal shopping mall. The Oracle offices are in this ritzy shopping/office tower called Lee Gardens.

Lee Gardens is like taking Greenbelt 4, making it look five times more expensive, and then spreading that super-expensive mall over four blocks. There is literally a mall every ten meters.

Every third car is a BMW. I only saw a handful of entry-level cars (a couple Mazda 3 hatchbacks, one Kia Picanto, a Toyota Corolla Altis) in my three days here. I saw a Brabus roadster, and BMW 5-series are quite common. Of course this is the Central district, there are supposedly more economy cars in the outskirts.

For the past three nights, I've seen this spectacle on Great George Street, near my hotel:



A closer look. It's Mister Pork Chop!



I can't figure why the Human Pork Chop would stand in the middle of the street for so many nights. Must be selling something.

Near Mister Pork Chop there were some demonstrators selling "Democracy Now" T-shirts and haranguing the passersby with anti-Communist invective. They had large banners reading "Heaven will swallow the CCP" (Chinese Communist Party). I didn't take a picture of them to avoid entanglements with Beijing.

One thing that is a bit jarring about being here is that the gap between rich and poor is huge, much worse than back home. I passed by a camera store which had tons of goodies in the window, including a $4000 (US) Canon EOS 5D. And a few steps away, a long-bearded old man was kneeling on the pavement with his cap in front of him and a few coins in it.

Sure there is that urchin family in front of Pacific Star Building, but in general the Philippines is a miserable place, so it's not too jarring to see extreme poverty. But here, there is this overwhelming sense of prosperity and capitalism, and then you see the old beggar.

Capitalism and Buy Me! screams at you from every direction. It is a bit of a downer walking along Hysan Avenue because I'm not in a buying state of being. It's like Hong Kong is pointless if you're not buying anything. But even if I didn't have bills to pay, being here alone is depressing, so I have no desire to even window-shop.

Oh well. I'll be going home tomorrow on the first flight. That is quite a heartening thought.

Extreme Ironing

There's this TV show on Nat Geo Adventure called Extreme Ironing. In the show, a bunch of intrepid adventurers (I mean, ironers), with flat-iron in hand and ironing board at their side, press clothes under the most unusual and dire of circumstances.

I'm not a particularly adventuresome person, but all of my trips begin with: the ironing board.



Hotels generally have nice irons, Tefal flat irons and sturdy ironing boards. I iron my work clothes because when traveling, I only carry a small bag for clothes, and my suspiciously-bulging notebook bag. So my clothes inevitably arrive rumpled. I tried the coat bag before, but it was a huge pain to carry on and off the plane. And I don't want the hotel to do the ironing because we're only allowed to do that if we stay in the hotel for more than three days (company travel policy), and the hotel usually takes all day to press stuff.

I arrived in Hong Kong today, and am at the Park Lane Hotel. It looks pretty impressive on the web site, but the reality is slightly less impressive. This is an old hotel, built in 1974, and it shows. The room is clean and semi-plush (after all, this hotel is an Oracle-approved one) but everything's a bit worn.

Oh heck, there's internet and that's good.

I searched for the nearest G2000 store online before coming here, to find their store in Causeway Bay. The hotel provided a nice map, although it lacked much detail, so I supplemented the map with a Google Earth satellite image.



Only took me about twenty minutes to find the G2000 store this afternoon. Took photos of the interesting garments with my Nokia E90, then walked back to the hotel and posted them on Picasa so that Lalai could pick the ones she wanted. Then I walked back, bought the goodies, and had my dinner.

All very well and good.

Tomorrow, I'll be at our client. No more shopping for me.

Building a GainClone Chip Amplifier

I've been reading about GainClone chip amplifiers on and off for years. In fact I have a fully-constructed but never powered-up chip amplifier constructed from a TDA2005 integrated circuit. It was destined as a car audio amp but we ended up buying a Pioneer MP3 head unit for the old car early this year.

After some discussion on the Pinoyboats forum, one of the members, Kuya Ton, mentioned the good possibilities of using a GainClone along with Wharfedale Diamond 9.1 or 9.2 bookshelf speakers.

The GainClone is an "open-source" rebuild of the famous $3500 GainCard from 47Labs. Kind of mind-boggling that audio fanatics will fork over $3500 for an amplifier constructed from a $5 power op amp.

In any case, I ordered some parts from RS Components Philippines (they have a minimum order of five pieces for the NS LM1875T, which I split with Kuya Ton).





We ordered the LM1875T chips from RS Components, even though they are much more expensive (PHP 180 each, or about $4) than at local Alexan Commercial in Megamall, because there's lots of fake IC's floating around, and the theory was that buying from RS Components would ensure getting the real deal.



Audiophiles also claim that using an ultra-fast recovery (35-nanosecond) soft diode results in improved sound! the usual diode used is the MUR860 from On Semiconductor, but RS didn't have any of those. They did have the MUR1520, which is a higher-power version but also TO-220, for PHP 49 each (about $1) in quantities of 25.

I had some old TO-220 heat sinks from my car amp project (these sinks were too small for the Thermotab packaged TDA2005 chip).



This heat sink is very similar to the Aavid Thermalloy Part No. BW/B/38 (7.2 C/W) but is larger in all dimensions. I guesstimated it to be good for about 6 C/W capacity. Since I have no mica insulator between the heat sink and LM1875T, it should be good for around 10W power dissipation. The thermal shutdown protection of the LM1875 should take care of the rest. 10W is pretty loud with decent speakers.

This is the schematic diagram of John Bell's Non-Inverting GainClone (NIGC):



Apparently in 1999-2002, the Non-Inverting GainClone was all the rage; then in 2002 everyone switched to Thorsten Loesch's inverting GainClone and its variants. But nowadays, the Non-Inverting version is back in vogue. One key benefit of the NIGC is that the (long) input signal wire is kept safely off from the feedback loop.

I used 1k and 47k for the feedback network instead of 680R and 22k because these resistors were what I had in my parts box. Also I used 330R on the input instead of 220R for the same reason. Similarly, i dropped the Zobel network on the output.

Initially I didn't have the 27k resistance to ground on the non-inverting input, because that's what Mark Houston's Nanoo design uses. However this didn't work for me, resulting in idle output voltage at Vcc (which needless to say would be horrible for the speakers). After a call to Kuya Ton and checking on Google, I verified that the pull-down resistor is needed and added it.

This brought down quiescent voltage to 40mV on channel 1, and 60mV on channel 2, as measured by my cheap Chinese digital multimeter.



My version has a much higher gain (nominal 47 or 33dB) as compared to 30dB for John Bell's version. I also changed the input resistors and got rid of the Zobel network on the output. Since standard line-level is 0.7V peak to peak, with a gain of 47 that would give 33V peak to peak, which with my 12V supplies would result in lots of clipping. Solution? don't crank up the volume on the signal source.

Here's my initial construction step:



Twisted the resistor leads onto the legs of the LM1875T so that the joints are mechanically secure. The feedback resistor is the large one between pins 2 and 4.

Both amplifiers, fully constructed. I made a major mistake - single star ground for both the power circuit and the small-signal circuit. I also ran out of hookup wire so I used some Cat-5 Ethernet cable, stripped out the little wires inside it, and used those. They are Gauge 24 so should be good for 3 amps of current.



I think the extensive use of recycled Cat-5 cable was a bad idea: in addition to the single ground, the small-signal input cable is just ordinary twisted pair, not shielded coax. This is the first thing I'll fix, as the amplifier hums when there's no signal.

Another, close-up view. The 27k input resistor is completely covered with heat-shrink tubing. I used a lot of heat-shrink tubing, as I'm paranoid. When everything's nice and sounds good, I will encapsulate the IC legs and solder joints with hot-melt glue to fix it in place.



Following Kuya Ton's advice, I used a couple of halogen transformers (used for powering 12V track lighting, PHP 300 or about $7 each) as the power source. Not such a great deal, a 12-0-12 VAC, 2.5A E-I core transformer from Alexan goes for about PHP 250, but looks much worse, and the halogen transformers are 4A each.

It's possible to wire the secondaries of the two transformers in series to get the effect of a center-tapped transformer, but one must measure the output voltage to make sure the secondaries are "in phase." Otherwise the net output voltage will be zero! also, the primaries must be wired in the same way, swapping the wires will cause the secondary voltages to cancel out.



Here are four MUR1520's in a standard full-wave rectifier bridge. Looks much more impressive than the garden-variety 1N4001 or 1N5401 everybody else uses! I mounted them on a small broken-off bit of perforated board from the TDA2005 project.



Here's the full setup. I cannibalized a couple of Kenwood 4-ohm speakers (actually they are the rear speakers from the unfortunate Mazda 626).



The speakers are in pretty bad shape (dust cap has fallen off of one, whizzer cones cracked and fell off, and the cones have gotten warped because of stuff that got placed on top of them).

I drove the amplifiers off my Toshiba notebook, and from our television set. Sound is detailed but lacks any sort of body, understandable because the speakers have no enclosure whatsoever. Also these are 4-ohm speakers for car audio, and thus not really suitable for the GainClone.

But at least I know they work. There's an objectionable amount of hum when no signal is present, about as much as our Altec Lansing ACS45 systems. Pretty bad for what's supposed to be a somewhat mid-fi system. I suspect it's the single star ground, the not-beefy enough grounding wires, and the ordinary twisted-pair wire on the small-signal input.

Also, the small heat sinks get warm. Not hot, but definitely warm. And this was at low volume. I will need larger ones. I'll fix all of the outstanding issues and see if the sound improves. If it does, I'll try to negotiate a purchase of those Wharfedales.

Nerd Test

Good SF Reading

I have meant to mention the Baen Free Library for ages now. I started reading from the Free Library about five or six years ago when there only were a handful of titles. And Eric Flint is right! people who read stuff from the Free Library turn out to buy more titles by the same authors.

I've bought several Honor Harrington space opera novels after reading The Honor of the Queen in the Free Library.

Anyway I've recently gone back to the Library and read two novels over the past couple days. You can check out the full index of titles as well.

Inherit the Stars by James P. Hogan is pretty good. Well worth the couple hours' reading. I love the last line of the book. Very much like Isaac Asimov's The Last Question (also a must-read for any SF fan).

Highly recommended! (it can't get much worse than free, right?)

Dumpling Lovers of the World, Unite!

Like a number of other people, I could eat siomai everyday. Or other types of South Chinese dumplings like hakaw, for instance.

The problem is that dumplings tend not to come cheap.

I'm not really a dumpling gourmand, but whenever I have a chance to leave the country, I look for dumplings. I was shocked and awed to discover that they don't have (and don't even know what) siomai and hakaw are in Beijing and Shanghai!

Anyway here's my list of places I've eaten dumplings, and their relative ratings, from top to bottom. Note that I'm only rating the dumplings, not the restaurant as a whole.

• Luk Yuen Noodle House (Ayala Center) - there's something about their siomai, maybe they put toxins in it or something, that induces me to keep coming back for more! even though their restaurant doesn't smell good..



• Zong (The Fort); Crystal Jade Restaurant (Plaza Senayan, Jakarta)



• Dimsum n' Dumpling (Metro Gaisano, Davao) - their hakaw is huge! and delicious!



• Gloria Maris (Greenhills)



• Mong Kok (Ayala Center, Power Plant); Imperial Garden (Marina Square, Singapore); North Park Noodle House (The Fort; Makati Avenue; Ayala Center). Special mention to Mong Kok for having (relatively) the cheapest dumplings of the lot, but four pieces for 55 pesos still isn't cheap.



• Summer Garden Chinese Restaurant (Tagaytay Highlands)



• Summer Palace (Shangri-La Makati). Amazingly for such a highly-hyped restaurant, the dumplings were forgettable. Aside: their over-hyped Peking Duck is nothing to write home about, either, completely shamed by Quan Jude in Wuzhou, Beijing.



• Le Ching in Greenhills (so-so)..



• Chow King (beginning to scrape the bottom of the barrel here..)



• that cheap Chinese fast-food stand whose name escapes me at the moment



• absolute rock-bottom: Fat and Thin steam-it-yourself siomai. If ever there was siomai that was made from cardboard and caustic soda (like that Chinese journalist reported) it would be this.

And for the piece de resistance, a great discovery on my part (the diametric opposite of the Fat and Thin which was an inglorious discovery). You can buy frozen wanton at the SM Supermarket frozen goods section. I found this brand of shrimp wanton from Thailand called CP. Just boil some water, add the sauce, and when boiling, drop in the frozen wanton for a few minutes.

Delicious! for me, easily comparable to Mong Kok and co-ranked places. Of course, this is garnished with Lee Kum Kee Chiu Chow Chili Oil. Without the chili oil, I find all manner of dumplings boring.

The CP boil-it-yourself wanton is sufficiently good (and cheap, twelve pieces for around a hundred pesos, I'm not sure of the exact price) that I feel no need to visit Luk Yuen anymore and tolerate the bad smell and expensive dumplings.

Fear and Loathing in Makati

I'm not quite sure if I saw anything quite so tasteless and immodest back when I was a scholar at Philippine Science High School.

It seems that money (multi-million peso Isuzu Trooper) and smarts ("Scholar on Board") don't guarantee taste or restraint..

EDIT: for the benefit of those who don't get why I call this "fear and loathing"

Philippine Science High School (colloquially known as "Pisay") is widely considered to be the best high school in the Philippines. And, more noteworthy, it's theoretically possible for anyone, regardless of income, to get in. When I was in PSHS, I had room-mates ranging from the extremely poor to the rather rich. I came from the lower end of this spectrum.

The stickers on the back of the Trooper spell

Bataan - Phisay QC Express (sic)

and

Scholar on Board

Now is that tasteless or what?