Is the SAA7220P/B really that bad ?

[gaetan8888]

Hello

The CD650 CD-player, who use a SAA7220 and a TDA1541, did use a 3k9 pull-up resistor BCK to +5V

Seem interesting, anybody try a pull-up resistor like this one ?

Thank

Bye

Gaetan

 

[Malefoda]

Hope you get an answer, looking for the right way to feed from a flipflop w or w/o the R in the line, so a can it be fed by a 5V clock directly or may I keep the RC wich is between the SAA7220 fed...
I still have that in mind:

... the 7220 swings 5v pk-pk on its outputs, and the 1541 only needs a tiny current centred c1.4v to switch - it's a current-routing logic; the excess voltage swing just pushes HF currents into the dac.

 

[2ndMarantzfan]

Hope you get an answer, looking for the right way to feed from a flipflop w or w/o the R in the line, so a can it be fed by a 5V clock directly or may I keep the RC wich is between the SAA7220 fed...
I still have that in mind:

Is anyone able to post or send me Guidos PMD100 TDA1541A schematic, the link in this thread no longer works.

 

[2ndMarantzfan]

Try again,
Is anyone able to post or send me Guidos PMD100 TDA1541A schematic, the link in this thread no longer works.

 

[rfbrw]

Pretty sure that schematic included a GAL. You would also need the code for the GAL if that was indeed the case.

 

[CyberPit]

f my memory serves me correctly, SAA7220 has 300H of DC offsets in its output data.
I would like to know is correct or not (Not sure, because it's three decades ago)

 

[abraxalito]

From memory its not that high, I seem to recall from my study 0x20. But it depends on the suffix letter of the SAA7220, I think I tested the B suffix.

 

[jpk73]

I am also looking for the PMD100 -> TDA1541A schematic but can't find it any more, and diyhifi.org seems to be dead. What I found is that Nakamichi diagram:

 

[jpk73]

Or would it be possible to use these circuits...?

 

[CyberPit]

From memory its not that high, I seem to recall from my study 0x20. But it depends on the suffix letter of the SAA7220, I think I tested the B suffix.

Oh, That's awesome. Thanks for your memory.
I thought it must be one of the unknown reasons for its sound characteristics. Because It decreases the chance of Zero-Cross distortion.

 

[jpk73]

Found some diagrams on the Chinese forum:

SAA7372 at 16.9MHz: but I thought, pin25 WCKO of PMD100 can be connected directly to LE of the TDA1541A...?

This is for the I2S output of the SAA7310: but shouldn't pin14 be tied HIGH...?

Glue logic for SM5813: again WCKO could directly be connected to LE, but the forum member wanted to match the timing requirements of the TDA...

Links to original forum posts: here and here and here.

 

[lcsaszar]

SAA7372 at 16.9MHz: but I thought, pin25 WCKO of PMD100 can be connected directly to LE of the TDA1541A...?

View attachment 1021070

The 74HC74 serves here as reclocking of the LE signal in simultaneous mode.

 

[jpk73]

What about this:

Would that work...? Or is the re-clocked version better?

 

[jpk73]

I made a simulation of the above version, it seems to work...

 

[jpk73]

And here is the simulation of the Nakamichi version...

 

[jpk73]

...and finally the simulation of the third version, plus screen shots!

 

[jpk73]

Sorry for hijacking this thread - I will continue here!

 

[vintageaxeman]

PMD-100: recommended!

Possible; yes.

Gluelogic: quite a bit

So can a PMD100 be directly substituted for an SAA7200P/B without any other circuit mods?

 

[rfbrw]

No. The SAA7220 is I2S in and I2S out i.e. serial L/R data in and serial L/R data out. The PMD100 is also serial data in but not I2S and parallel left and right data out.

 

[vintageaxeman]

No. The SAA7220 is I2S in and I2S out i.e. serial L/R data in and serial L/R data out. The PMD100 is also serial data in but not I2S and parallel left and right data out.

Thank you.