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

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#203
If your Onkyo doesn't provide balanced output from DAC, the best is to built integrated DAC in the player and connecting it with I2S interface. The output stage would have to be balanced.

As to the improvement over Toshiba, I think the sky is the limit. But to get the best sound out of this transport requires either hard work with tweaking and comparing, building different enclosures, bases, suspensions etc. or a bit of luck with proper decisions and choices. 😉
 
#204
cd pro player

Hi Peter,

I looked at the power supplies on the website, but although I know most of the components suggested, I don't think I'd be able to build my own psu's from the schematics. So I have two options if I want the cd-pro, the first is to buy kit psu's and just configure them for the required voltage (will be more expensive obviously). Or I've found this kit cd player based on the cd-pro http://www.akustik-perfekt.de/concert_Huk.htm
(which is also expensive), but If I'm able to pruchase the case and psu's for this and then perhaps add a different dac. By the way does the cd-pro come with a digital output that can be wired to a rca plug type connecter (as you would find with most digital outputs), or is the digital out requiring a different type of connection?


Thanks
Raj
 
#205
its strange that nobody have designed a complete supply pcb for the cdpro2 unit - and made it commercially available....... it isn't too hard......!

well i actually have such a pcb, fr-4 double layer - 2 x jung regs (5 and 9 volts) 317/337 regs for the rest, complete with rectifiers and everything.......also delay thing.

😎
 
#206
Re: cd pro player

Raj1 said:
..... By the way does the cd-pro come with a digital output that can be wired to a rca plug type connecter (as you would find with most digital outputs), or is the digital out requiring a different type of connection?
Click to expand...

The best connector for coax DigOut is a 75 ohms BNC (be careful: most BNCs are 50 ohms and only few 75 ohms).
As rca plugs are standard among audio (and cheaper) almost every manufacturer use them.
But if you are building a CD transport and a DAC, I dare suggest to use 75 ohms BNCs (and RG178U mil specs cable for interconnect).
 
#208
cd pro player

Hi,

anyone with any ideas on this player?

http://www.akustik-perfekt.de/concert_Huk.htm

The reason I ask is cause the power supplies for the diy transport that peter made would cause me problems to build on my own, so I was thinking about this player instead (is more expensive though. The only problem is that I was thinking of an upsampling dac, which would of course render the dac in this player useless. Peter have you tried the various dac's yet (non oversampling, upsampling etc), if so which did you prefer?

Thanks
Raj
 
#211
Peter Daniel said:


Did you try other regulators. Some people commented that jung regulators not always sound the best with certain digital circuits.
Click to expand...


well no, i didn't try other regs.
as far as i'm concerned, the jung reg. are "worldclass" and they will do a much better job compared to all other chipregs.....!
but perhaps a fully discrete reg will be even better, i don't know.

perhaps i shouldn't have mentioned that i had such supply pcb.
because of the cost and that it is fairly sophisticated, i have decided not to offer it for sale.
those who know those jung regs also know that they can be a bit tricky to work with, and there is also lots of very expensive components on the pcb.
in the end the complete supply for the cdpro2 will cost more than the drive itself.......i don't think that any one is prepared to pay that much....but i could be wrong...?

BUT .... i could design a specific supplyboard for the cdpro2, using only standard components like lm317/337 regs and panasonic fc ....etc.
i was thinkin' of contactin' mr. thevissen and suggest that this supply could be available from his website.....?

troels
 
#213
my cdpro2 supply pcb consist of two jung regs. (ad797 and lm 329 + many other components - look at the photo from alw) + 3 x 317/337 regs. there are 4 full bridge rectifiers (IR 31dq10)
2 expensive common mode chokes + 4 encapsulated talema trafoes.........and do you know how much it cost to manufacture a fr4 double layer, 7oMu copper, 1,5 mm - fully proffesional pcb ?
and it took me a lot of time too.......!

.........the trafoes alone costs more than 150 euro, please ask alw about his price for the regs he is designing...and let us know.

i'll see if i can get a digital camera, then you'll see + i have other nice things too!!!!!!!!!😎
 
#217
12s or spdif

Hi,

my project for the cd-pro 2 is underway (power supplies), I'm having a bit of a problem deciding on the 12s connection though. There doesn't seem to be many dac kits that support this directly. I contacted jocko homo about his dac which does support 12s, however jocko said he wouldn't make any more boards unless there was enough demand. What are the problems that could be encountered when using this type of connection, and are there any dac kits around that are configured to counteract these issues? I'd really like to use the best connection possible and 12s does seem theoretically superior to spdif. If I use a spdif connection I'm being compelled towards the broadhurst dac, with this I'd assume that it would be best mounted within the enclosure for the
transport and as close to it as possible in order to keep the digital cable length short and reduce jitter.

Also the standard audio outputs on the transport pcb, what is the voltage output? Could these be connected directly to rca jack's and connected to a preamp?

Thanks
Raj
 
#218
Hi

Can anyone comment on this piece of advise from the daisy-laser web site ( http://www.daisy-laser.nl/homeoptics/page34.html ) on the CDPRO2 I2S output?

"The I2S output is there to allow direct input for DAC's or processors making use of the signals as offered at the I2S output. There is no system clock provided for external DAC's.
The wire length should be below 20 cm for the best results."

"The I2S bus was designed for Inter IC Signal exchange and not for signal exchange between 2 boxes. For external DAC's or DAC's in a second box best is to use the EBU/Spdiff output with twisted wires"

Does this mean the I2S output cannot be used with an external DAC i.e. Perpetual Technologies gear?

Thanks

Tim
 
#219
I2s

Hi Tim,
Currently I have a length of about 40 cm for the three I2S signals going from the transport to my DAC (TDA1543 NON-OS).
Kal Rubinson wrote a nice article in Audioelectronics 1, 1997 : "Get on the Bus". Backissues available from www.audioxpress.com
Maybe it is better to "sharpen up" the signals at the DAC end and/or using some form of outputbuffer.
Anyone has a idea how Audio Alchemy did it or ...........P-1A. Sorry forgot the full name:bawling:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=15479
 
#220
Hi Tim,

I am currently using the I2S CDPRO2 output as follows:

From the connector of the CDPRO2 to the output connector (6 pins DIN) on the DIY CDPRO2 enclosure I have used approx 15 cm CAT5 UPT cable.
From the 6 pins DIN connector to the DAC (2 x TDA1543) I use 50 cm CAT5 UPT.

Per signal I have used 1 twisted pair. One for the actual signal and one for the ground. The grounds are connected together on the DAC ground and the I2S CDPRO2 ground.

I am not sure if this is the way to do this, however it works since the first time I tested this.
------------------

I would be interested in some comments on this! Do I hurt my signal?

Best regards,

Peter
 
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