Elegant way to feed parallel data-input DAC chips ?

[Bernhard]

Hi,

anybody knows if there are DENON chips for seriell to parallel conversion between os filter and PCM54 in DCD1500 ?
DCD1520 has it but is 18 bit, maybe I can use it ?

Or any other player that uses 2 x PCM 53 or 2 x PCM 54 and NPC os filter and dedicated chip for data conversion ?

I do not want to built with a lot of 74 HC164/574

[rfbrw]

Try the Teac Esoteric D1 thread. There is partial schematic showing serial to parallel conversion using custom devices. Perhaps you can buy the chips as spare parts.

[gmarsh]

There's no reason you can't use an 18-bit parallel output; just don't hook up the two LSBs.

If your oversampled output is I2S and you're scared of the board area associated with a TTL-based solution, you could use a XC9572 or similar CPLD to do the conversion.

[Bernhard]

Originally posted by rfbrw
Try the Teac Esoteric D1 thread. There is partial schematic showing serial to parallel conversion using custom devices. Perhaps you can buy the chips as spare parts.

Those are the 18bit chips and I have them in the DCD1520.

[Bernhard]

Originally posted by gmarsh
There's no reason you can't use an 18-bit parallel output; just don't hook up the two LSBs.

So if a SM5813 outputs 18 bit, the first 16 bits are the same as if it would output 16 bit ?

[gmarsh]

Originally posted by Bernhard


So if a SM5813 outputs 18 bit, the first 16 bits are the same as if it would output 16 bit ?

Should be.

[rfbrw]

Originally posted by gmarsh

Should be.

It is. The '5813, like many of the NPC devices, uses a burst clock. In 18 bit mode it puts out a burst of 18BCK cycles. In 16bit mode it puts out two less, ignoring the last two bits of data.
gmarsh, I don't think you quite appreciate the pin paranoia that afflicts some in this place. Two 18 bit dacs alone would need 36 pins calling for two PLCC44 devices or a single PLCC84 device, a situation that would have more than few reaching for the smelling salts.

[Bernhard]

Originally posted by rfbrw
Try the Teac Esoteric D1 thread. There is partial schematic showing serial to parallel conversion using custom devices. Perhaps you can buy the chips as spare parts.

The SM5813 in this DENON schematic outputs 20 bit and DENON built another discrete 2 bit with 4053 switches to get 18 + 2 = 20 .

[rfbrw]

The SM5813 is a 16/18/20 bit device and the PCM64 is also an 18bit device. I very much doubt that there is a need to 'make' additional bits.

[Bernhard]

Originally posted by rfbrw
The SM5813 is a 16/18/20 bit device and the PCM64 is also an 18bit device. I very much doubt that there is a need to 'make' additional bits.

No doubt, they did it.
The schematic schows traces bit1-bit18 from SM5804 to PCM64 and traces bit19-bit20 to 4053.