[jefemeister]

Bringing this topic back up, I am now in a position to assist anyone who might need help with the Philips control software.

 

[strohmie]

I've hit a wall with this just because I have so many other things to do. The display/control board power supplies that I built still have yet to be tested, and I haven't gotten around to finding parts for my power supplies.

Stupid grad degree.

I decided it would be easier to simply buy the pre-built control board rather than creating a new one myself. Certainly saves time. I have a DAC board that I'm going to build eventually (TDA1541A-based) and eventually will get around to trying out an oversampling DAC as well. Too much to do.

 

[was ist los?]

jefemeister, perhaps you may be able to help BrianGT at diyaudio.com. He has a CD-Pro2M board open source project.

 

[strohmie]

I'm not sure what ever happened with that -- I volunteered to be one of those to get the control board but haven't heard back about it. It's possible that I just missed a thread update or something, time to go check.

 

[jefemeister]

Quote:

Originally Posted by was ist los? jefemeister, perhaps you may be able to help BrianGT at diyaudio.com. He has a CD-Pro2M board open source project.

I did a quickish search over there and didn't find anything about this project. Any links?

 

[strohmie]

Quote:

Originally Posted by jefemeister I did a quickish search over there and didn't find anything about this project. Any links?

http://www.diyaudio.com/forums/showt...threadid=37959

 

[strohmie]

gsferrari pointed out to me that I needed to give this thread a much-needed bump.

First, a view of the DAC I'm building...

This design is a non-oversampling one built by a good guy over at diyaudio named Pedja Rogic. Unfortunately it was part of a limited run and probably no boards are going to be available from here on out. I might recommend anyone wanting a good non-oversampling design try out the one being sold by a member named tube-lover over there, which gives multiple output buffer topologies.

Either way, this one is based on a single TDA1541A chip, which will receive I2S input directly from the CD transport itself. Without the CS8412 SPDIF receiver, I am able to remove two of the power supplies from the board. I'm still left needing two 7-9V supplies, two 17-18V supplies, and one 21-22V supply for the rest of the board. The output buffer is based on the AD844 op-amp -- for more information on the topology, please visit Pedja's website.

This will take the place of the onboard DAC of the CD transport. Basically once it's built all I need to do is buy a couple transformers, and it will be ready to run. Here's a close-up of the nearly finished output buffer, which is about as maxed out as I can make it:

The +9V and especially the +5V supplies for the CD transport are extremely important in terms of its sound quality. For this reason, I'm putting special care into building these supplies. I have two Jung super-regulators that I'm building based on a board designed by ALW Audio.

The above is the +9V supply, full of black gate FKs. Given the current requirements of the +9V, I'll probably need to heatsink the LM317. I'm waiting for the final components for the +5V supplies, which will hopefully be here by today or Saturday.

Next thing I have to do is figure out how I'm powering all these devices. For the display board and +9V supply of the CD player, I plan to buy a pair of Amveco toroidal transformers and probably mount these on a separate printed board to supply the accessory boards. The +5V supply will probably get its own dedicated transformer. The five different required voltages for the DAC is going to take some work -- I'm debating whether to get a custom-wound toroid or simply use three additional Amvecos. Either way I'm looking at four to seven transformers in one box.

If anyone has some clever ideas as to what I should do regarding the transformers, I'm all ears.

More updates as I continue on.

 

[Dreamslacker]

Actually, you can do this on a breadboard. It would take up less space and you can also add a reclocking circuit to the TDA1541A.

Take a look at this circuit to see how it can be done:

http://peufeu.free.fr/audio/extremis...plement_3.html

Simply subsitute the TDA1541A into the TDA1545 slot and instead of Con1, you'd tap the signals from the I2S output of the CDPro 2 module.

 

[strohmie]

Quote:

Originally Posted by Dreamslacker Actually, you can do this on a breadboard. It would take up less space and you can also add a reclocking circuit to the TDA1541A.

Yea, I figured I could do it this way. But I wanted mainly to see how Pedja's output buffer performed, since it's gotten some good press around diyaudio. 90% done now, just missing the decoupling caps (probably getting some ERO MKTs) and then I'll be good to start testing the power supply capabilities. I'll probably ask for a custom made transformer for a Christmas present.

I'm actually thinking about only using the microprocessor of the CD-Pro control unit and not bother with powering the display board. In other words, the CD player would look more like a turntable, without a specific track or time readout which I don't personally *ever* use anyways. Perhaps it's the minimalist in me.

So at this point I have the following voltages I need to account for...

TDA1541A board:
Two +7-9Vrms transformers and one +21-22V for the TDA1541A
Two +17-18Vrms transformers for the 1541A output buffer

Transport:
One +7-9Vrms transformer for the microprocessor
One +12-14Vrms transformer for the CD-Pro2M's +9V supply (jung reg)
One +7-9Vrms transformer for the CD-Pro2M's +5V supply (jung reg)

Optional:
Two +9-16Vrms for a reclocker (Kwak clock)


I'll probably have a custom toroidal transformer made for all the 1541A functions, since the regulators for that area already available on the 1541A board itself. I'll probably use a simple Amveco encapsulated toroid for the +9V Pro2M supply and the microprocessor supply, and then a good separate one for the +5. Next chance I have I'll be testing the jung regulators I built for the CD-Pro2M.

 

[jefemeister]

Make sure to keep the necessary wattage of the supplies in mind. The transport motor can take up to ~1.5A when it spins up.

 

[DHT 2A3]

I'm planning on building a transport, and was thinking of using a gutted NEC 602 in the case below donated from my old AA transport. Don't know of a newer IDE-based CD-ROM drive that I could gut and use - anyone know? The NEC has that nice solid metal chassis. It is that or a Philips CD-PRO2, but they're so so expensive. Problem with the NEC is the display board (too small for my application and not enough information for me, like track number, etc). Take a look at the pics and I'd love some advice! The box is perfect for a top-loader, and has internal metal shielding around some of the boards. The controller board and display board were in one box, and the mechanism in another.

[sorry for the poor quality photos - scanned images before I had a digicam]

 

[GoRedwings19]

Quote:

Originally Posted by strohmie I'm planning on making a CD player that includes an internal DAC with a separate power supply from the transport power supply. This would all go in one chassis, with the possible option of placing a PPA board inside if desired. This is up in the air momentarily, but at the very least the transport and DAc will be in the same unit. I remember seeing that CD-Rom transport before. The idea here is to use the CD-Pro2 (pro == professional grade) module, which is very high quality and would certainly be leaps and bounds above the NEC. Many high end players use this tranport, while others use a CDM12.# (industrial grade with a number of incarnations, and also very good but still hard to come by). The jury is out as to which of the Pro2 or CDM12 are better overall, but both have much potential.

I am not a diy'er but there are a few tips I might be able to give you. As you know I own a ML combo. They have split it up into three parts. Transport>dac>power supply.

The reason for this is the power supply chassis contains three power supplys. These are all regulated. Power supply no 1=supplies power to the left channel of the output stage of the dac.

Power supply no 2=supplies power to the dac decoding stage.

Power supply no 3=supplies power to the right channel of the putput stage.

The power is supplied via 3 independant power leads. I suppose the manufacturers believe that this will supply the power without spikes and without interfering with the rest of the electronics.

Most high end manufacturer's build two box systems as they feel it is the way to go. Even naim have there two systems with transport+dac in one box and the power supply in a completely different box.