Friday, December 14, 2007

Det'nator - Update 2

Front panel in fabrication stage.. will be superb! Mark my word..

Pre-amp.. just got all the semiconductors. Had to redesign a new one. Current one, NOT happy with the little 'hiss' that I detected.. Currently have at least 3 different designs. Have to assemble /build each one and test...

BOMB II- already have the parts. Need to design the board. 100-150 Watts! Should make MaDZiZ happy... this could end up as MONOBLOCKS... urghhh the temptations..

Found a super-duper totally discrete buffer circuitary! Have bought all the parts, have to start designing the board/layout.. haih.. so much to do.. so little time!

Monday, December 3, 2007

Det'nator-Update 1

After much thought, I decided to scrapped the current preamp circuitary. I am simply NOT satisfied with its performance. Not that it is NOT good but I believe d'BOMB requires a better performance/higher quality preamp... more research to be done here! The keyword here is simplicity yet high performance.. tall order huh?

Have found some basic designs which I need to go through and pending availability of parts, need to assemble the unit and do some preliminary testings.. looks like the project gonna be slightly delayed.. all for good reasons! Hope the customer understands..

Sunday, December 2, 2007

Current project: Det'nator

Current in the assembly (laying out the board and transformers).

The Det'nator is actually an integrated amplifier, d'Bomb and d'Fuse(preamp).

I have got all the necessary hardware for it except some tools which I require at some satge of the process.. listening tests had been done with the prospective buyer. He liked it, I liked it too! I may have to build one myself! Certainly beat the heck out of my Technics!
The BOMB now resides in a proper casing, before it was resting on a plank! I managed to get a reasonably priced black casing from JP. The FUSE (preamp) is a new inclusion. It costs more than the BOMB! It came with tone control and loudness but I have bypassed all the unnecessary circuitaries.. we audiophiles like playing 'flat' right?
Initial spec of BOMB requires the use of a 4A transformer but after extended listening tests, I decided to settle with a 3A one as it's already very LOUD when driven at high volume! I can't believe that it is only rated 40W+40W! 4A tests offers no audible sonic improvement. Further more, the 4A transformer is BIG and HEAVY that will require unnecessary bigger casing, it is also more expensive!

After much thought, the front panel will have a gold volume control with an LED light position indicator.Have NOT decided with the colour, will have to experiment. The main power on LED will be WHITE as requested by the customer. Personally I like orange/amber which I used on d'DAC. It 'glows' in the dark... Wanna stay away from blue as almost everything that now came especially from China have blue LEDs.. It's the craze now I guess...
The main switch will be installed at the back together with the RCA inputs and speakers binding/banana posts.The IEC socket now come with buildin fuse.

The medium size 'transformer' is actually a suppressor, to minimise mains interference. So far it looks (and sounds)good. Can't wait for completed assembly before commencing burn in/further listening tests...

Watchout for updates!

Tuesday, November 13, 2007

PCM58 DAC- a quickie (part 3)

Got back quite late due had to transit to customer place to listen to spanking new setup using a NAIM NAIT 5i integrated amplifier.. this I believe the best amp yet..

Just got the HiFi setup running and currently listening to an audiophile CD called BOSSA VOICES- 15 Brazilian love tracks.. wonderful album expecially when played by the Bomb.. hehe .

Ok.. here's the picture of the current setup: DVD/CDP playing via the PCM58DAC driving the TDL RTL3 via the Yamaha DSP-E200 pumping juices out of TheBomb.. enjoy mike.You asked for it!

PCM58 DAC- a quickie (part 2)

Second day (night actually coz its after midnight!) of auditioning.I'll make this short.. tired and sleepy already!
Configuration changes: Using the BOMB in place of the Technics integrated amplifier, the SU-A900MK2.
Findings: The apparent 'narrowed' soundstage has been restored. mid especially the highs now is a little bit more polished. The lows.. this is where the BOMB really shines.. well articulated and controlled. This is the icing on the cake..

Final configuration: a Yamaha Natural Sound DSP introduced to the setup to be used as a preamp.. was using the DVD/CDP digital volume control as system volume/preamp.
Final verdict: The Yamaha DSP pre-amp is that red cherry sitting on a top of the great cake. This IS the sound setup that had me amazed at 2.15 in the morning. Oh I almost forgot.. closing my eyes and 'viewing' the soundstage.. I can't locate my speakers!

Sunday, November 11, 2007

PCM58 DAC- a quickie (quick review, hehe)

The DAC has been running for the last (almost) 5 hours.

Before that FYI, I have just acquired a transmission line speaker, and these are known for the 'extra' bass( it has 2 bass drivers). So my system is really bass heavy, with very low end right down to 30Hz (tested). Listening to it is like having a 'loudness' button pushed. Very punchy and very suitable for rock, fast music.

After a false start(no sound from DAC) found out I need to enable the digital out from the DVD menu. :P Having done that, I played through two outputs: normal discrete out and via the DAC. Then while playing a CD just select the different output for A/B comparisons.. Amplifier used was the Technics SU-A900MKII(90+90Watts Class AA). Speakers: TDL RTL 3. Speaker cable Cable Talk Talk 3.1. Digital signal cable, Canare L-4E6S (DIY)

Playing via the DAC is like switching the 'loudness' button OFF! Loose boomy 'uncontrolled' bass now becomes tighter and articulated with being overcontrolled. The noise floor has somewhat lowered and some instances, disappeared altogether! Vocals instead of being too much projected(like the singer is singing hard into the microphone), now has been laid well back into the soundstage. One thing for sure, the imaging is ROCK SOLID! The soundstage however seemed to be narrower BUT did not loose the necessary ambience. This lead me to dig out ALL my favourite CDs and hear this new found sound.. on a new DAC via a new speaker system..hehe.

Instruments are now very distinct.. can pickup all the pieces very clearly. I imagine this like a camera/photo.. before this the images is slightly out of focus. Playing through the DAC is like everything just went into supersharp focus all the way to the horizon!.. Again,the background noise/silence just went totally dark..

Enough said! More listening to do now.. have to burn enough hours before change of stock opamps to my favourite! More on this later...

Pictures shows the DAC during assembly and testing with my superduper DVD cum CD player.


Saturday, November 10, 2007

We're going DIGITAL!

On the left is the Yulong's PCM58 DAC. Picked up the unit from a LYN bulk seller in KL. Bought the transformers(yes, its that many-7!) and found a 'budget' casing to go with it! Will be busy building this hopefully tomorrow.. can't wait to connect it to JTA's reference CDP* and see(hear) how it would sounds... Will update with completed unit and short review. Watch this space!

*ref CDP is an 'elcheapo' DVD player but sounds fantabulous due to it's onboard DAC. This would give the Yulong's DAC a run for the money.

Friday, November 9, 2007

Mission Accomplished.

Saturday morning started busy having one thing in my mind; must complete the 'Bomb'. After two hours,one hour was spent for soldering alone. The remaining being used to sort the components and planning the whole job.
This is the 'prototype' just after first 'power on'.No smoke or smell of smoke...phew! :D
It's on a plank just to position the mainboard and the transformers.. If it's working, then gonna get super duper casing for it...
Connected to 3 difference type of speakers(2way DIY, Panasonic 2way and Monitor Audio R252). Source was a Sony PCDP.. The sound was amazing! After one hour later, its even more amazing.. details, low end extension.. I can't simply believe my ears. Pix on top shows the 'wet run' just out side the dining hall.. don't wanna 'blow' anything up... it is,'the bomb'! Hahaha.
Contacted the 'customer' to try out in his system. Lets see how it faired head on with the customer's existing Audiolab 8000P power amp setup... more surprises coming up... watch this space.

Sunday, November 4, 2007

Another project to revive

Ok.. this one a started project that was put on hold due to lost of interest in head-fi..
that's 1/2 board of HDPA= High Definition Portable Amplifier.. total discrete, no ops amp..

Saturday, November 3, 2007


shortWelcome to the creation of jaztech blog.
Why jaztech? Its gonna be a commercial name for me to produce some 'stuffs' to carry the name jaztech.. more on this later.
Also for jaztech 'customers' to keep track of jaztech product updates.. (soon I hope) :D

So far first product is a 24VDC PSU for a friend to be used as a power supply/charger for a GoVibe6 headphone amplifier.. HAve NOT send this yet.. to include an Acoustic Simulator too..oops have to start that too!

Whats coming?

1. 40W+40W OCL Power Amplifier for a friend. Status: Not started yet.Update:compleetd. see Mission Accomplished. This is the 'bomb';)
2. Yulong PCM58 DAC KIT. Status: Waiting delivery. When? GOK :D (God Only Knows)
Item has arrived! picking up tonite :D
3. Acoustic Simulator for headphones

Thank you.. see u around.