Nos Cdp

wmincy · 3rd January 2009, 03:47 PM

hi,

recently I read an updated article on CDP-227ES converted into NOS mode posted by Lukas, the guy who mods a long list of CDP with his lampucera circuitry.
http://www.lampizator.eu/LAMPIZATOR/...digital_filter

In his article he showed how to convert the digital-filtered TDA1541 into a purely NOS DAC taking i2s signals out from CXD1125 (which output is a 2's complement) while adopting a kind of shift register that delayed the LRCLK signal the sony chip in order to transform 2's complement format into i2s format.
This method seems to work fine, I did tried but on a TDA1543 instead.

Well, if I want to use this "converter" on a CDP with PCM56, can I use it in the same way or it needs some modification? Do you guys have any suggestion? thanks.

wmincy · 6th January 2009, 02:24 PM

I made it!

It was easier than I thought: the CXD1125 output format is a 2's complement which will fit the PCM56 input, in fact the PCM56 doesn't work with i2s input format.
The connection is very simple:
CXD1125 PCM56
pin76 BCK pin5 CLK
pin80 LRCK pin6 LE
(should invert the LCRK for the other
channel)
pin78 DATA pin7 DATA

If anyone of you want to try, why not!!

wmincy · 23rd January 2009, 12:28 PM

here is my NOS CD player:
DENON DCD-1700

attached some pictures of the circuit board.

wmincy · 23rd January 2009, 12:35 PM

here is the wiring schematic

wmincy · 23rd January 2009, 12:38 PM

DIGITAL FILTER BOARD:

CXD1125 + SM5804

wmincy · 23rd January 2009, 12:43 PM

The core of this CD player:

PCM56 "K" type!!

I then bypassed the whole audio section by using a passive I/V converter: 500 ohm resistor.

acid_k2 · 23rd January 2009, 01:31 PM

hi wmincy

good good!

Do you have installed another PCM56 board for the other channel?

I'm thinking to use a similar method to exctract audio from a PC cd-rom, using data inside the cdrom and an external dac.
Dac is based on PCM56, but I dont know the data format of the cd-rom (sony or I2s philips), so I don't know if I need a shift register or not. There is a solution for that? What's happens if I connect the dac in a wrong way? Damage, or only noise from the dac?

Ciao

wmincy · 23rd January 2009, 03:28 PM

hi acid_k2,

since there are two identical PCM56Ks on the circuit board i just took picture of one.

Well, regarding the CD-ROM internal circuitry, I didn't have any experience with that unless I get the schematic to find out pins that correspond to the digital interface connection, such as I2S.
Me too, I'm working on a CD-ROM based player of course binding a external DAC, for now a TDA1543 NOS.

Don't worry about the wrong digital input connection, my previous experiences recalled me that there won't be any physical damage just noise at the output. However it's quite hard to make a wrong connection, remember to check twice!!

Hope to see your work on the forum soon!!

saluti

acid_k2 · 23rd January 2009, 03:51 PM

thanks wmincy

I''ll try to play with it during the week-end...
I have a sample-hold DAC based on single PCM56P- L version

to use for test... I'll sacrifice that...

guytou · 23rd January 2009, 09:16 PM

hi wmincy , does your 1700 as a provision for MSB adjust from datasheet ?(on PCM56) . It seems not , that would be a way for upgrading the sound

3rd January 2009, 03:47 PM	#1
wmincy diyAudio Member Join Date: Sep 2003 Location: Italy	Nos Cdp hi, recently I read an updated article on CDP-227ES converted into NOS mode posted by Lukas, the guy who mods a long list of CDP with his lampucera circuitry. http://www.lampizator.eu/LAMPIZATOR/...digital_filter In his article he showed how to convert the digital-filtered TDA1541 into a purely NOS DAC taking i2s signals out from CXD1125 (which output is a 2's complement) while adopting a kind of shift register that delayed the LRCLK signal the sony chip in order to transform 2's complement format into i2s format. This method seems to work fine, I did tried but on a TDA1543 instead. Well, if I want to use this "converter" on a CDP with PCM56, can I use it in the same way or it needs some modification? Do you guys have any suggestion? thanks. __________________ the fever of DIY HI-FI will NEVER be cured !!!!

6th January 2009, 02:24 PM	#2
wmincy diyAudio Member Join Date: Sep 2003 Location: Italy	I made it! It was easier than I thought: the CXD1125 output format is a 2's complement which will fit the PCM56 input, in fact the PCM56 doesn't work with i2s input format. The connection is very simple: CXD1125 PCM56 pin76 BCK pin5 CLK pin80 LRCK pin6 LE (should invert the LCRK for the other channel) pin78 DATA pin7 DATA If anyone of you want to try, why not!! __________________ the fever of DIY HI-FI will NEVER be cured !!!!

23rd January 2009, 03:28 PM	#8
wmincy diyAudio Member Join Date: Sep 2003 Location: Italy	hi acid_k2, since there are two identical PCM56Ks on the circuit board i just took picture of one. Well, regarding the CD-ROM internal circuitry, I didn't have any experience with that unless I get the schematic to find out pins that correspond to the digital interface connection, such as I2S. Me too, I'm working on a CD-ROM based player of course binding a external DAC, for now a TDA1543 NOS. Don't worry about the wrong digital input connection, my previous experiences recalled me that there won't be any physical damage just noise at the output. However it's quite hard to make a wrong connection, remember to check twice!! Hope to see your work on the forum soon!! saluti __________________ the fever of DIY HI-FI will NEVER be cured !!!!

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23rd January 2009, 01:31 PM	#7
acid_k2 diyAudio Member Join Date: Oct 2006	hi wmincy good good! Do you have installed another PCM56 board for the other channel? I'm thinking to use a similar method to exctract audio from a PC cd-rom, using data inside the cdrom and an external dac. Dac is based on PCM56, but I dont know the data format of the cd-rom (sony or I2s philips), so I don't know if I need a shift register or not. There is a solution for that? What's happens if I connect the dac in a wrong way? Damage, or only noise from the dac? Ciao

23rd January 2009, 03:51 PM	#9
acid_k2 diyAudio Member Join Date: Oct 2006	thanks wmincy I''ll try to play with it during the week-end... I have a sample-hold DAC based on single PCM56P- L version to use for test... I'll sacrifice that...

23rd January 2009, 09:16 PM	#10
guytou diyAudio Member Join Date: Mar 2005 Location: marseille	hi wmincy , does your 1700 as a provision for MSB adjust from datasheet ?(on PCM56) . It seems not , that would be a way for upgrading the sound

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