Tubed VCD player mods

Hi Guys,
With time in my hands, I thought I tried to salvage my ageing VCD player called WEIGE.... yes remember this brand in the early 2000s when DVD players were just crazily priced?

This WEIGE player was actually a pathetic music maker. The output section uses 8V single rail power supply to power the quad opamps! You can expect dull lifeless sound.

Much earlier say 7 years ago, I tried modding this player. Adding bypass caps on all caps that I see on the board, changed the opamp to BB4134PA, add new power supply for the transport section, add AC filter and chasis dampening (using a combination of bitumen pad and wax dropping from a candle).

Ok it worked a little bit, just a little bit. Due to the still pathetic sound, this player was just prematurely retired into the shelves.

Right up to today, I lampisized this player. Yes added a lampha...

Basically added an anode follower la... simple terms.

But the key is, add the anode follower directly after the DAC chip.

Adding a tube buffer after the opamps won't do anything.

WEIGE VCD player - pathetic in stock


Birds eye view - left section is the 3 mains transformer (2 tx for the 8V and 5V, 1 tx for tube anode voltage supply), top right section is the 6DJ8 anode follower tapped directly from the DAC chip which is just directly below it


6DJ8 anode follower tapped directly from the DAC chip which is just directly below it


DAC chip is the ES3207 - analog output is from pin 47 & 48. In stock form, they output voltage at 0.6Vac pk when I played 0dB 1khz sine wave test track. Not too strong nor weak.


6DJ8 anode follower close up - input cap uses 4.7uF Black Gate N, 1Kohm gate stopper, Output cap uses 2.2uF 400V Russian PIO K75, Vsupply is 138VDC, anode resistor is 10Kohm, Cathode LED bias to 1.8V. With this, the gain is much stronger than a stock CD player. I'm getting about 8V output. But that's just nice for my SET with low gain.


Anode voltage is derived from a simple step down 240V - 120V isolation transformer.


Overall block diagram of the tube stage power supply.




All in all this one single mod of the anode follower has totally transformed this player into a very very capable one. I'm not kidding. You would think that reclocking is more important - but no... it's the analog stage that's the most important.

The sound has really transformed to a deep and wide soundstaging capable player. It's sweet yet dynamic. I'm totally amazed.

cheers

If there's something worth in the Weige, its likely the common Sony KSS-213C loader and optics. Thats frequently used transport in some established brands, not bad at all since my Rotel does have the same thing but not play VCD's obviously.

I was thinking on this lines since I have stashed somewhere another Taiwan make, obscure brand DVD that have a loader and transport that use an IDE interface, very much like the PC. In fact can even swap out the whole DVDROM drive and fit in something else. This is a rare feature among other commonly found budget priced DVD players. When I've the time and parts, I would do something to it since I've also a full box of assorted pre-amp tubes that I don't have use at this point of time. Till then!

Something that I wanted to do but have been holding back.. ie to 'lampize' my VCD player..

cmboy wrote:If there's something worth in the Weige, its likely the common Sony KSS-213C loader and optics. Thats frequently used transport in some established brands, not bad at all since my Rotel does have the same thing but not play VCD's obviously.

Yeah it uses this laser module... the only thing is the damn tray mechanism... really screwed up and flimsy.

That's why I gave up modding this player moons ago. Until this valve stage came along

My motivation was that, just 2 days ago, I helped a friend to repair his Sony-227ESD with a Satch tube output that was faulty. Even though the TDA1541 chip was still in oversampling mode, the sound was still awesome and beguiling after repairs.

Guess what, this VCD player has exceeded the sound quality of the tubed Sony !!

The improvement is probably due to the higher voltage supply that I used and also pumped in much higher current into the tube.

cheers

CT-Boy wrote:Something that I wanted to do but have been holding back.. ie to 'lampize' my VCD player..

Yeah man, add that "lampha" into that VCD player of yours.

cheers

Optimum and highest possible DC B+ is essential to get the best out of the tube's rated potential. I don't like those tube circuits that operate at safe values, i.e. half or less its actual amount that can be applied. Although the tubes may last hellava long time with those safe voltage or biasing, the SQ is another story altogether.

Gud job on your lampi story.

Wikin,
You don't happened to have some spare tubes lying around, no?

cmboy wrote:Optimum and highest possible DC B+ is essential to get the best out of the tube's rated potential. I don't like those tube circuits that operate at safe values, i.e. half or less its actual amount that can be applied. Although the tubes may last hellava long time with those safe voltage or biasing, the SQ is another story altogether.

Gud job on your lampi story.

Yes agree with you... all my tubes are run quite hard to get the best possible micro dynamics. They tend to sound sweeter and clearer too.

cheers.

CT-Boy wrote:Wikin,
You don't happened to have some spare tubes lying around, no?

Got.... have some EH 6922, RCA NOS.

cheers

Wikin wrote:

cmboy wrote:Optimum and highest possible DC B+ is essential to get the best out of the tube's rated potential. I don't like those tube circuits that operate at safe values, i.e. half or less its actual amount that can be applied. Although the tubes may last hellava long time with those safe voltage or biasing, the SQ is another story altogether.

Gud job on your lampi story.

Yes agree with you... all my tubes are run quite hard to get the best possible micro dynamics. They tend to sound sweeter and clearer too.

cheers.

Also cannot be too much plate voltage la, too much and the sound becomes really hard and dynamic!

Gotta hit the sweet spot...

dixchen wrote:

Wikin wrote:

cmboy wrote:Optimum and highest possible DC B+ is essential to get the best out of the tube's rated potential. I don't like those tube circuits that operate at safe values, i.e. half or less its actual amount that can be applied. Although the tubes may last hellava long time with those safe voltage or biasing, the SQ is another story altogether.

Gud job on your lampi story.

Yes agree with you... all my tubes are run quite hard to get the best possible micro dynamics. They tend to sound sweeter and clearer too.

cheers.

Also cannot be too much plate voltage la, too much and the sound becomes really hard and dynamic!

Gotta hit the sweet spot...

Of course man, that's called tube kamikaze

cheers

Great.. Wikin,
lemme check out the lampize circuit and see what are required.. I have a spare tranny balance from my tube pre-amp project..