CD PRO 2 - The making of a high end CD Transport

Since I finished my Aleph 5 and it's pretty good I thought I might start the construction of a CD transport based on Philips CD Pro 2 mechanism, before I devote my efforts to finishing the GAX (whoever red Aleph-X thread will know what I'm talking about). For more info check the thread
I want to built my unit with rigid suspention and separate power supply. For proper perspective check 47 Laboratory site
Eventually I will add no oversampling DAC through I2S based on 6 AD1865 chips. Since I didn't get much feedback in my other thread concerning regulators for digital circuits I will try LT1085 chips and maybe upgrade later. This is all I need for my transport. Check this site often because in response to some e-mails I will be posting more pics as the project developes. I estimate two weeks to complete.;)


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Only 6 ad1865!! :D Are thoose N-K or N-J?

Currently I'm building a dac using only one (N-K). I wanted to make it balanced but there is too much work in it and I've don't have a working cd-player, so mabye later.

I'm using LM317/LM337 as regulators in my dac. So far the count is 10 positive regulators and 6 negative.

Good luck with the project, I'm looking forward to reading about it and looking atall the nice pictures :p

I have just finished building the power supply and testing the cdpro2. The mechanism seems to work terrifically though I can't comment on the sound yet since it is still not mounted on a chassis.
I noticed you are trying to mount the drive mechanism on rigid platform like the "flatfish" you refered to. Do you have any thoughts (advantages/disadvantages) regarding mounting it rigidly versus the spring suspension recommended by philips. I am now contemplating this rigid way of mounting the mechanism myself as it appears quite interesting.

I´m just at the moment finishing my CD PRO 2 CD Player.

I made a very heavy and solid wood case 320*420*90mm with a lexan piece on the top, to see the display, and let in the IR signal from the remote. The transport looks out the lexan piece 5mm to put the CD on it.

I made it as simple as possible.

Costs are about 400Euro + material for chassis and powersupply.

Be shure to build a power supply which gives +5V at turn on before the other voltages, and takes away the other voltages before the +5V at switch off.

Otherway the +9V without +5V may cause damage at the transport, or the -22V without the +5V may cause damage at the driver IC for the display tube.

At the moment its playing Orff, carmina burana.


2001-02-06 6:18 am
regarding the I2S lines


Thank you for the tip.

Can these lines drive cables to an external dac directly without
buffers at the connectors, ie are buffers already installed
at the existing pcb to drive the cables connected to the
I2S pins?

On a related question, can an external clock (Kwak Klok for eg) be used just to clock the dac if the I2S is used?

thanks in advance
oaktsh said:

I noticed you are trying to mount the drive mechanism on rigid platform like the "flatfish" you refered to. Do you have any thoughts (advantages/disadvantages) regarding mounting it rigidly versus the spring suspension recommended by philips. I am now contemplating this rigid way of mounting the mechanism myself as it appears quite interesting.


I modified the mechanism frame to accomplish rigid mounting. The original top base was removed, and new, much bigger base was made out of 3/16" aluminum. I thought of thicker material, but then, picking out the CD would be more difficult. That base will be mounted on a platform made of a composite material with a cutout for the mechanism. There won't be any cover on top or a CD compartment.
One might think that CD compartment with door will somehow isolate CD from external vibrations. After reading review of YBA player in FEB 97 issue of Stereophile I came to different conclusion. They made comparison and used the same player without top cover and both Yves-Bernard (the man behind YBA gear) and Jonathan Scull (whose opinion I value a lot) agreed it sounded better without cover. I can only suspect that vibrations created inside the CD compartment are worse that the ones coming from the outside.


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You have great ideas! I am quite anxious to see the final CDplayer. Details of the project would be greatly appreciated. I am presently trying to find some heavy aluminum for the platform of my cdpro and will problably mount the mechanism similar to the way you are doing. I am interested in the article you are referencing. Do you know how I could get a hold of it?

I am currently using LT1086 +5V in the power supply. Based on measurements done by my friend, this chip appears to perform better than others like motorola etc... As you already know, the 5v digital/analog supply is the most important section. If you find a better regulator to use here, I would be interested to know. My power supply is completely separate also each. I am still contemplating the connector to use to connect the power supply to the drive mechanism.

I didn´t play until yet with the digital outs.

But there is a web site:

Of mr Gavalotti how has experience with this, you should mail him your questions.

Also its possible to ask Mr Nico Thevissen at daisy laser, NL who runs this site

and he will give information you need for CD Pro 2. Also there are links to the docs of the CD Pro:

I conected only whats absolute necessary for using the CDP, i´ll study schemata and plans for external DACs before building one.
That's the type of connector I'm using for separate PS. As ususlly I get it from my neighbourhood Chinese Store. They call it video connector and it has 10 pins, Swiss made. You can see it in action on my BOZ preamp:
As to article you might try, although it's probably not part of archivum. It's YBA CD 1 Blue Laser CD player in February '97 issue. I also plan to install blue LED because apparently it improves the sound as well.;)


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The standby button will shut down the power to the drive mechanism and display but the power supply side will still be active. If you have the eprom loaded with version1.3 on the display board, you will need to use this button to reset the table of content every time a new disc is loaded as the blue DISC "TOC" button on the remote does not work. I believe Nico is working on a fix for this.

The 10pin connector, is there a brand name on it or is there indication if it is swiss made? Oracle uses a 15pin DIN computer connector, but I find the current draw for the digital/analog section would be insufficient.
If I press the standby button the CD drive stops rotation, the head goes in its normal position like at stop, the display shuts all segments down, only the tube heating is still on, i can see that at night without any lamp on around. If press standby again the CDP wakes up, normal startprocedure like at power on. I use standby instead of power off.
The work continues

I carved out the base for the transport (or should I say core?). It's made of some kind of composite material I bought surplus and is quite heavy. I compared that material, as a platform for turntable, with MDF, granite and aluminum and it always sounded better. So I figured out it might be good material for my purpose. The other choice I was considering was glued 3/4" maple plank. But the weight would be less, maybe a drawback in that case.
Top plate, or platform supporting transport would be installed to it, as well as front panel containing display, rear panel with all jacks and side panels made of another composite. The additional circuitry would be attached at the bottom without bottom cover.


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Progress report

Do I love to work with aluminum. ;)
Chassis slowly coming to a shape. I decided to do everything with separate modules to avoid complicated resonance modes. Front control panel, back panel for connections, both sides: power supplies. In the center a space for transport platform suspended by 3 spikes. The platform is not connected with anything else. 1/4" bottom plate will be resing on 1.5" composite platform.


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