| 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 |
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| 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. |
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| 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 ! |
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| 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 |
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| 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
???? |
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| Jocko Homo |
SAA7220. It is located right in front of the DAC!
Jocko |
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| arold19 |
Thank you very much.
I found the datasheet here
http://www.alldatasheet.co.kr/datas...PS/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 |
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| 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 ? |
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| Jocko Homo |
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 |
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| 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 |
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| rfbrw |
| quote: | Originally posted by 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 |
Digital input for what? |
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| arold19 |
For plug an other cd player in this one !!!!!
I want to use this cd playes has a DAC only, without laser disc.... |
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| 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. |
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| 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 ? |
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| till |
| quote: | | In a normal CD player, there a received chip or no ??? |
no
| quote: | | II have to buy the CS8414 to feed my philips filter ? |
yes, or 8412 |
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| 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. |
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| arold19 |
No digital input but digital output... no good for me...
thank you very much for your help.
I will buy a digital receiver. |
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| arold19 |
| Do I have to cut the pin between the SAA7210 and the SAA7220 before solding my CS8414 ??? |
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| Jocko Homo |
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 |
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| rfbrw |
| quote: | Originally posted by Jocko Homo
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...........)
Jocko |
You have to bear in mind your experience in this topic probably exceeds the total time some of the posters have been alive. And you must admit that if you haven't much of a background in this topic being faced with FSYNC, LE, LRCLK, WDCLK and WSAB all being the same thing or not depending on the IC in question, can be a bit daunting.
Still, sometimes I do wish people would make just that little bit more of a effort. |
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| rfbrw |
| quote: | Originally posted by arold19
Do I have to cut the pin between the SAA7210 and the SAA7220 before solding my CS8414 ??? |
The datasheet for the SAA7220 shows the SAA7220 acting as master to the SAA7210 and TDA1541. Not only will you have to isolate CLAB,DAAB,EFAB,SCAB,SDAB,WSAB and XSYS, you will also have to disconnect the crystal connected to the SAA7220 if it is present. EFAB, SCAB, SDAB and XSYS can be left floating as the first three have internal pull-up and pull-down resistors and XSYS is an output. |
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| Jocko Homo |
I know how daunting it can be. That is why I suggst that they buy a DAC kit, and learn from it. At that point, they can ask "Hey....I have such and such DAC kit with a TDA1543. Is it possible to adapt it to the inside of my CD player with a dead laser and make a DAC out of it?" They will at least have some sense of what is involved.
Yes, if all the chip companies usesd the same terminology, it would easier. Even for guys like us.
Jocko |
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| arold19 |
Today, i received my CS8414 and it is very small.
I don't understand very well the things you are talking about.
I just try to do something with this high quality cd player and I can't succes without your help.
I will do the best I can to connect my CS8414 on the SAA7220 with the reply of (RFBRW) in mind
But what you mean by :
(you will also have to disconnect the crystal connected to the SAA7220 if it is present)
thank you very much |
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| arold19 |
Excuse me again, but I saw some schematic of the CS8414 with the TDA1541 witout using the SAA7220 ...
So, can it be easier to make my DAC without the SAA7220 ??
thank |
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| Jocko Homo |
Maybe.
You will need a different post filter in the analog stage.
Translation: one that filters out all the **** above 22 kHz, as you won't have a digital filter to do that for you.
Translation: the one that you now have in your CDP will not be sufficient.
Jocko |
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| rfbrw |
| quote: | Originally posted by arold19
But what you mean by :
(you will also have to disconnect the crystal connected to the SAA7220 if it is present)
thank you very much |
See page 19 fig.13 of the SAA7220 datasheet. It shows the SAA7210, SAA7220 and TDA1541 connected together. Connected to pins 10 and 11 of the SAA7220 is a 11MHz crystal. If you are going to connect the CS8414, you will have to remove the crystal and connect the master clock from the CS8414 to the SAA7220(XIN) and the TDA1541(SCK). |
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| arold19 |
Thank you very much, I understand well now.
And what about the Pin 23 MUSB and the Pin 22 ATSB of the SAA7220. I cut the pin or I don't touch at that ? |
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| rfbrw |
| quote: | Originally posted by arold19
Thank you very much, I understand well now.
And what about the Pin 23 MUSB and the Pin 22 ATSB of the SAA7220. I cut the pin or I don't touch at that ? |
Isolate ATSB. It has an internal pull-up so you leave it unconnected. You can do the same with MUSB but you will get noise every time the CS8412 has no input signal. I would connect it to VERF (pin 28) of the CS8412 but you have to invert the output of pin 28 first. |
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| arold19 |
I need your help !
Yesterday, I finish to put my CS8414 in my cd player and when I plug it, it play very well. I was very proud but, after a couple of second, I understoud that there's something wrong.
The 2 output are the same !
The signal of the right channel is the same that the left one.
Do you know what can cause this ?
Have you ever see this ?
Can I correct this ?
thank you very much ! |
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| arold19 |
Or maybe I can bypass the digital filter ???
It sound better with the digital filter ???
I saw there some 200 ohm resistor between SAA7220 and TDA1541, this is correct ??
I'm waiting your answer ! |
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| arold19 |
ok, I found it !
pin 4 of TDA1541 is DATAL/DATA, I don't have to put the the master clock of the CS8214 here and I have my 2 channel...
The sound is good but it disturb a bit in some music, maybe the output voltage of this cd player is to much for my bride of zen...
thank you vey much for all |
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