Use a DAC of a CD-player ?

[arold19]

Hello, I have a very good quality cd-player but the transport is broken. I know that the analog circuit of this cd-player is excellent. I want to know if it is possible to convert my CD-player to a DAC with a digital input ???

thank you

 

[dangus]

Possibly.

One of the many projects I haven't got around to yet is the "almost-free-DAC" based on a broken CD player I got for 25 cents. Not a high-end CD player by any means, but it does have a digital filter that I have a data sheet for and a pair of Analog Devices DACs, so it shouldn't be difficult to cut away this corner of the pc board, add regulators and better opamps in the analog section, and kluge an S/PDIF input (probably using an AD1892 receiver/sample-rate-converter chip, although that may be overkill).

So, identify the digital filter chip, and figure out how to feed it.

 

[arold19]

I'a not very experimented in DAC circuit... But i saw in some chematic, that the RCA 75 ohm input cable go to a (DIGITAL INPUT RECEIVER) chip before the (DIGITAL RECEIVER) chip !

So, the digital input have to go where exactly ?
excuse me, I don't know very much in digital system.

For the modification, I will do nothing, the power of this cd player is the analog parts. This cd player was created by Steve Mc-Cormack in 1987. At this time, it was a very very good sounding cd player.

thank you for your help !

 

[Jocko Homo]

You have to know what digital filter it is to know what format to feed to it, either I2S, or left-justified.

If "Mud Squid" made it, it is probably Philips based, and it takes I2S. My guess is the chassis is a "Maggot Box" CDB-650, right????

Jocko

 

[arold19]

Yeah, it is a Mod Squad cd player. A plilips CDB-473 modified...
Inside, I can saw the TDA1541, but I cannot find the digital filter ?? Anybody can help me ??

TDA5708 28 pin
XC86604P 40 pin
SAA7220 P/A 24 pin
SAA7210P 40 pin
MAB 8441P T113 28pin
X2816BP 24 pin
TDA 5709 20 pn
8703E8206 18 pin

????

 

[Jocko Homo]

OK......I was off by one model number.......

SAA7220. It is located right in front of the DAC!

Jocko

 

[arold19]

Thank you very much.
I found the datasheet here

http://www.alldatasheet.co.kr/datasheet-pdf/view/PHILIPS/SAA7220.html

But I don't understand very well that. Maybe I have to put the digital output of my cd player in pin #2 and 3 ??
#2 = CLAB Clock
#3 = DAAB Data

But I very don'T know.
Do you know where is the input of that chip and how to use it ?

thank

 

[arold19]

Ok, I just saw the DEVELOPMENT DATA in page 19 of the datasheet.
the SAA7220 work with the SAA7210, maybe the input is in the SAA7210 chip ?

 

[Jocko Homo]

There isn't one input......

There are 4:

Master clock

Bit clock

Word clock (aka L/R clock)

Data

There is a thread about hooking up a CS8414 to NPC and Philips filters. Read it. Get the data sheet of all of those parts........read them........then ask questions.

Jocko

 

[arold19]

Yeah, I understand they are 4 connexion between the SAA7210 and the SAA7220. But, I need to know where is the digital input of all of this ?
I read the datasheet, but it is not very clear for me !
thank

 

[rfbrw]

Yeah, I understand they are 4 connexion between the SAA7210 and the SAA7220. But, I need to know where is the digital input of all of this ?
I read the datasheet, but it is not very clear for me !
thank

Digital input for what?

 

[arold19]

For plug an other cd player in this one !!!!!
I want to use this cd playes has a DAC only, without laser disc....

 

[till]

You need a reciver chip like CS8412, CS8414, AD1892 to recive spdif from the other CDP. The reciver chip will feed your DAC / SAAs, as you could see in the thread Jocko told you.

 

[rfbrw]

http://www.diyaudio.com/forums/showthread.php?s=&threadid=42788

http://audiochips.net/data/cs8412.pdf

 

[arold19]

In a normal CD player, there a received chip or no ???

here the list of chip I have in mine cd player..

TDA5708 28 pin
XC86604P 40 pin
SAA7220 P/A 24 pin
SAA7210P 40 pin
MAB 8441P T113 28pin
X2816BP 24 pin
TDA 5709 20 pn
8703E8206 18 pin

one of this one is a receiving chip ?
if no, I have to buy the CS8414 to feed my philips filter ?

 

[till]

In a normal CD player, there a received chip or no ???

no

II have to buy the CS8414 to feed my philips filter ?

yes, or 8412

 

[rfbrw]

None of them look like receivers but others may know better. Does the M/S player have a digital input on the back? If not, you will need something like the CS8412 or the CS8414.

 

[arold19]

No digital input but digital output... no good for me...
thank you very much for your help.
I will buy a digital receiver.

 

[arold19]

Do I have to cut the pin between the SAA7210 and the SAA7220 before solding my CS8414 ???

 

[Jocko Homo]

YES!!!!!

Do you guys have trouble reading/understanding the datasheets? Or is it a case of wanting someone else to tell you what to do. There have been a series of questions the last week or two that make me wonder..........

(Several guys have done this......not singling out one guy...........)

If you really are in over your head, perhaps you might want to buy a cheap DIY kit that you can get accustomed to this stuff with. It might be easier in the long run to learn by applying a similar solution before trying to come up with one on your own.

Jocko