Sliding Bench...

A misnomer it must be.

Not sure if it is the need to be seen as embracing avant-garde designs or just trying hard to be stylish, but the metamorphosis of Dhoby Ghaut MRT brought about by Dhoby Xchange must have gone into the heads of those SMRT folks for them to justify buying those circa 26" metal benches that are placed close to the wall, with a slight tilt on the seat and a smooth finishing on the surface.

These seats are impossible to be sat on as it will cause you to slide forward and eventually fall off. Those who can master the legwork to keep from falling may well be giving their legs a much needed workout.

But i've observed with much amusement, people trying those benches, only to migrate off to the traditional marble top benches what is not just more comfortable, but stable and not as frustrating.

Maybe the only reason why they had this installed is to amuse the kids, as Lucas will demostrate in the below clip:



Give me a wall instead... and I'll gladly lean on it...

I think as far as sitting objects with amusement value is concerned, the head honchos at NLB have scored with flying distinctions with their Italian plastic chairs in the kids section at basement one, central lending library. These chairs can be sat into normally, and if turned on their front, it can be used as a rocking horse. But the customer service there is a fine example why we would never reach service levels like Japan.

Modding the PS1

I spent some time to carry out the suggested modifications at Mick Feuerbacher's site. I did not have the correct capacitor value for the output stage replacement, but since the PS1 is stripped to the pcb, i took the time to perform the other mentioned mods such as removal of the dc blocking capacitors after the DAC, and also removal of the muting transistors. I also removed what looked like the mod chip. Initially I thought it was removed as I did not see the same implementation as shown here.

Looks like different shops mod the sets differently. ;)

Will get some small value blackgates for the output stage replacement... Not sure if I can listen to this next week as I am expecting to pick up some Zebrano veneer for my speakers.

Some pics here.

A/B impressions of PS1

The anticipation of this moment since early this week... i pulled together my horses and men for this session. The other source is a Marantz CD50 using a TDA1541A dac. My 5687 preamp, d3A/VV302B DRD amps and my Diatone PM610MB speakers were called to duty.

Sequence of A/B is always PS1 first, followed by CD50 for each track.

Discs used are 1 - Plastic Flower from Op4, Lena Park (Korean Artist), 2 - The Power of Love Songs CD1, Fish Leong (Malaysian Artist), 3 - The Hong Kong Hifi show CD (2007 I think), 4 - You'll Hear Better Songs and Memphis Tennessee from Early Hours (Hybrid SACD), Eleanor Mcevoy.

Impressions are that the PS1 presents a lower output voltage to the preamp, the bass is rounder and not as profound, soundstage is less deep, and it has a more mellow presentation when compared to the CD50. It also seems veiled in comparision, with the CD50 giving a cleaner and clearer sound.

Perhaps after the mods, it will be better... I can only keep my fingers crossed.

Direct Reactance Drive

A long overdued post. You might have already seen the pics at my picassa albums.

This project actually started out in June/July 2004, and was my first attempt to build a tube based amplifier. On hind sight, it was a little ambitious to build a 300B mono block as a first tube project. Nonetheless, there are people who did it. Me, I only got it right on the second attempt.

Inspired by Sakuma san and Josh Stippich, I wanted to make use of those nice mercury rectifiers in my circuit. The RCA83 was bought locally at a rather high price. Netting these tubes on ebay would cost a fraction of what I paid.

I did lots of reading about tubes, and also got some online education of such stuff at DIY Audio. The Net is such a wonderful tool... I even attempted to create a DRD calculator in excel that helps calculate the resistor values and B+ required when certain inputs such as driver and power tube operating points are furnished. I was suggested to use the Siemens c3g as a driver for the 300B tube.

Suffice to say this this first pass project did not pass with flying colours. With a pair of inefficient (87db/m?) Totem 1 bookshelves, hum was evident even at 1.5m away.

I rebuilt this amplifier around Oct/Nov 2006. This was also partly due to reading the success of Luis Gascón with his DRD using d3A/300B on diyaudio.com. I built my version with d3A as the driver, but using LED biasing.

Testing this on my Mitsubishi Diatone PM610MB speakers (around 93 to 94 db efficiency), hum was only evident when my ears are around a feet away from the driver. All heaters are using AC for this build. Needless to say, I am very happy with my DRD amplifiers. ;)

More pics here.

Found... the elusive... PS1

Like they always say... Persistence pays off. This is quite true when I managed to find a Playstation 1 at a Cash Converters for SGD29 with 2 controllers, AV cable, one memory card and a power transformer for 240vac to 110vac.

This particular unit that I have is labelled a 100vac version. The store assistant asked if 100vac was ok. I immediately told him that I am ok. He then commented that I'm a confident customer... Actually I was thinking of building a PSU for the 7.6vdc and 3.6vdc that would be required by the unit.

When he brought the unit to the cashier, he also went to collect the accessories. It is in this bag that I spotted a transformer that seem to indicate 240vac. After paying, I went off to find a quite spot where I can inspect the bounty. And I was spot on. ;) It was indeed a step down transformer.

The moment I went back, I plugged in the AC and powered it up. The green LED was lighted. Hurray... I quickly did a test of the audio via the TV. Seemed that one channel is ok, but there was some hum. Perhaps due to wiring. Will do a real test soon.

Since the serial number or identifier sticker at the bottom of the unit is removed. My next instinct was to open the unit to determine if this was the real mccoy. I did not realize that the dac is actually quite small. I had to strain my eyes to verify the numbers on it. It was indeed the Ashahi Kasei Microsystems (AKM) AK4309AVM DAC 16 bit Stereo Delta Sigma chip. This mean the PS1 that I have is the SCPH100x version.

My next steps would be the output stage mod and the PSU mod as mentioned at Mick Feuerbacher's site. Let's take a real serious listen to how good this thing actually is. ;)

More pics here.

The Last Sonic Frontier?

Probably the most neglected area in one's pusuit of audio enjoyment... and this would be sound treatment of the listening room.

The conundrum for me, then, is... how would you know what to use when planning for a new room? Especially when you have never heard your system in it before.

Well... perhaps a leap of faith and some reading. ;)

Initially I wanted to DIY something like the RPG Hemiffusor. There's a website that had the dimensions to do this. But I think this woud be a real time consuming affair...

The diffusor seen above was purchased as part of a mass order offered by joamonte on echoloft. I took me around one month before I finally pick up the 8 diffusors from him after he told me that they are ready. It was a late night affair when I made the pickup. I had the fortunate experience to listen to his system. It was really good. It is definitely showroom material... in fact, showrooms should take a leaf out of his book.

I might be adding some diffractal for the front, but now I am having problems with mounting 8 diffusor panels... not enough space in my odd shaped room. Perhaps I will go with 4 at the back and have a hanging ceiling for the other 4.

Rest of the pics here.

Outing at Lower Pierce Reservoir

After breakfast at one of the prata place opposite Teacher's Estate, we went to Lower Pierce Resevoir with Edna and her mum. Edna is Lucas' biting buddy in infant care. I think they express their liking for each other by biting... good thing the parents are cool about this. ;)

Now Edna and Lucas are at different child care centres. The only time that they meet is when we go out for such trips together. The last one was at Night Safari with Edna and her parents, and also Nathaniel and his mum, plus Lucas and us.

Some pics of the sunny trip here.