How Can I Restore a S/PDIF Output After Removing SAA7220 Digital Filter chip

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audioxcel

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Joined 2010
I bought an NOS module that replaces the SAA7220 digital filter in my Philips CD880. Because the S/PDIF output comes from the SAA7220 chip, I no longer have capability to use my CD880 with an external DAC.

I would like the option to be able to use my player as either integrated CD player or a transport with a DAC. Can anyone help me do this? PS: I have only marginal knowledge of electronics; so please talk to me like the newbie I am.

Can I just take the output from the transport board and somehow connect it to the S/PDIF out connector?
 
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audioxcel

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Markw4

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Joined 2016
The more expensive board has its own MCLK clock and converts all I2S input to one standard output sample rate.

The cheaper one has an external MCLK input and will retain whatever sample rate (within the range it supports) that you want to use. However, you need to have an MCLK signal to drive it with.
 
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audioxcel

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Joined 2010
Markw4 said:
The more expensive board has its own MCLK clock and converts all I2S input to one standard output sample rate.

The cheaper one has an external MCLK input and will retain whatever sample rate (within the range it supports) that you want to use. However, you need to have an MCLK signal to drive it with.
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Thanks. I thought that was the difference. I think I will go with the one that has the oscillator on the board. That way I won't have to risk adding jitter to the master clock circuit of my CD layer. I can also, upgrade the oscillator if I get a hair up my **** to do so.
 
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rfbrw

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Joined 2001
audioxcel said:
I think I will go with the one that has the oscillator on the board.
Click to expand...

I wouldn't if I were you. The WM8804/5 are SPDIF I/O devices not sample rate converters. When configured as a SPDIF transmitter, the output data rate is determined by input data rate at the LRCLK pin of the AIF interface. LRCLK and MCLK must be in the same clock domain. The one without a fitted oscillator module gives you the option of taking MCLK from the CD880 and sending it to SPDIF TX or fitting an oscillator module to the TX and sending that MCLK back to the CD880. What you cannot do is have two different clock domains.
 
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audioxcel

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Joined 2010
rfbrw said:
I wouldn't if I were you. The WM8804/5 are SPDIF I/O devices not sample rate converters. When configured as a SPDIF transmitter, the output data rate is determined by input data rate at the LRCLK pin of the AIF interface. LRCLK and MCLK must be in the same clock domain. The one without a fitted oscillator module gives you the option of taking MCLK from the CD880 and sending it to SPDIF TX or fitting an oscillator module to the TX and sending that MCLK back to the CD880. What you cannot do is have two different clock domains.
Click to expand...

Thanks. I did not know that. I don't know why they would include an oscillator if it can't be used for the output. What is AIF?
 
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