A DIY Cd Player Using Philips VAU 1252-10 Cd Engine. First take a look inside your CD player to see if the CD engine you're listening to.. looks like this...
It doesn't???? Well, you have a chance to build you own CD player using this motor, one among the best CD engine worldwide and you can do it in one weekend-time. Interested? Then read the following...
Well, let's start from the beginning. We (me & Andrea) were looking for a good Cd player to give new life to our huge stock of CDs. We were also a bit disappointed of the "nasty sound" of some medium level Cd players compared to a medium Vinyl recording so... what can we do?...
After a number of visit to hi-fi shops and good deal of weekend's discussion in front of a glass of good beer, the possibilities were clear:
- Turnkey solution: Spend a lot of money (3000+USD), buy one of those high-end Cd player, perhaps with tube output. Compel the whole family to stay at home for next 2 summers.
- Do it "a little" by yourself : Buy a commercial CD with a good trasport unit. eventually improve power supply, forgetting all the rest . Build yourself a DAC,
- Do everything by yourself ... ;)
Of course for nasty solder workers like us the last was the "Top Option", But how to do that?. We started a extensive search in the web, to find a supplier for a CD transport unit. After all the search was easy: there are a few, but those found or sold complete kits at high prices or had medium level mechanisms . At last we came across to what we need: Daisy Laser.
Daisy Laser is the Official distributor of philips Optical storage Components. Unfortunately it doesn't sells to privates. But we fuond there a very kind fellow, Nico Thevissen who actually provided us much more than we expected: all the "critical part" we needed to build a complete Cd plyer with remote control. Thank you Nico!
Besides Nico runs a site with all the technical documentation and building tips. Ask him for the password to browse it: http://www.daisy-laser.nl/homeoptics/
There you can buy the CD-PRO unit (thise displayed at the top of this page) that is a "plug & play" unit consisting of:
- the professional VAM 1252-10 Cd mechanism
- the premium 7000 assembly, that's a SMD PCB underneath the mechanism with:
- a microcontroller to drive the motors with a simple 3-wire protocol
- a servo processor to decode digital signal, and do error correction
- a high performace audio DAC
The VAU 1252-10 mechanism ranks among the best philips products. It's intended for countinuos operation and is caracterized by:
- a hard alluminium frame to improve stability
- a set of suspension springs and grommets to improve mechanichal decoupling from the chassis
- 3 beam LDGU with olographic pick-up
- Low mass actuator for fast and accurate focusing
The DAC (TDA1305T) is of "bitstream" type ... ok ok, I know lot of us prefer multibits dacs, with current output and x-former coupling .... but please listen before... This dac has fairly good performaces and a very nice sound . Summarizying the key feautures of this IC:
- with wide dynamic range (18bit)
- Low Noise (108 db S/N)
- Low distortion (0.003% typ.)
- Good output swing (1,5 V RMS)
Besides CD pro unit has two digital output if you want to build your external DAC:
- a IEC958 output (compatible with SPDIF)
- and a more complex I2S/ CDG data output for AV applications
At the end of the story to build a complete Cd player using a CD pro unit you need only to build a power supply and a controller for the Premium 7000 unit.
Nico for a few money can supply a nice and simple controller based around 80C32 with an external IR remote control. Actually you can buy only the most important components such : PCB, micoprocessor, EPROM, RC handset etc.. So at the *very* end of the story what you have to do to get all work is buildind the power supply!. A weekend is enough!
The power supply
Using the schematics provided in Nico's site we've built a slighlty different power supply. The main differences are the following:
- We use Five different Power sources,made from two C-core x-formers with multiple secondary windings, and electrostatic screen
- LM309K instead of 7805 is used (we've a box and seems to do things better);
- A trimmer for brightness control has been added
Here comes the schematic. Please excuse us for the look : after all this is a "OLD ECONOMY " design, no computer but only paper, rubber & pencil.... ;).
click to enlarge
As you can see we've also changed the value of some components mainly in the 21V section for the display unit to reduce Zener power dissipation. We've also a very simple layout for the PCB. This design is intended for double sided PCB, the lower layer is used for electrostatic shield, components are soldered direcly on the upper layer. All the regulators IC are mounted on a alluminium dissipation frame.
click to enlarge
Easy isnt' it???
The first prototype, photo gallery and construction tips
From our experience costruction is easy, still at hand of a medium skilled DIYer. The main problems we found was in preparing an electrostatic discharge-free environment to build the controller unit. Infact he display section of the controller unit uses a IC that's very sensitve to ESD discharge. Beside this IC has to be soldered directly on the PCB and its pin are very close one another, so it's better to have a nap before soldering. To build this PCB we've prepared this DIY Anti static Plane:
If you use graphite powder remember to put a little, rub hard witha a paper towel, and take away all the powder in excess using a clean paper towel. Besides remember to:
- dress cotton clothes (not wool or sinthetics)
- dont' use rubber shoes
- dont' move from the chair until you've finished. Standing up from a "office chair" charge your body. Have all the components at hand (or have someone to pass you ;))
If you delay the whole costruction, stock the PCB in a anti-ESD envelope. Use a soldering station with very thin end. Soldering Stations using low voltage (12-24V) are preferreable. Now the Photos:
Look before you leap!
Building the Driver PCB. Note the copper ring around andrea's wrist. Andrea is wearing rubber gloves coated with graphite. Andrea's finger. Is pointing to the bended array resistor on the display driver IC.
Mounting the Display Frame
DONE!!! - The worst is passed
The power supply ready to be connected to the driver PCB and CDpro Mechanism
There are two great points with this CD:
Playability: CDPRO can play all those (bad) CD that "jump" or had some "click" problems. I had two copied CD that couldn't be played in my previuos player (No toc readed). With CDpro no problems! . Sound: What I appreciated most is its very clear detailed sond, expecially in low passeages. Compared to ours previuos Cds there is also a big difference in the extension. Andrea agrees in that adding that also the soundstage recostruction is something to tell.
It's difficult for us to find some downsides. For me comparing this CD to *very* High-end multibit DACs It lacks a bit in dynamics. For Andrea the low register can be a bit "far", but this is also a problem of some choices made in our power amplifiers. And he's corrected it retuning the cathode capacitors in the first stage of "Monotriodino".
As you can se our overall judgment is *very* positive. We delayed the costruction of an external DAC because the sound is very pleasant and ranks face to face to high-end Cd, for a tenth of the expense. All this costed us about 700 euros! (600 euros for two complete CD pro kits) then 100 euros for the others componets) so each of us spended about 350 euros: boy this's the price only for a low-end multibit Dac!. Using silver teflon cables to connect directly the DAC output to the integrated amplifier "Francesca" ( 3 stages from CD to speakers) We had a new experience in sound. Thank you another time Nico!
That's all folks, Listen and ENJOY!