BB PCM63 DAC only for CD transport

[merlin el mago]

Hi guys,

I'm trying to make a DAC for my CD transport, I have two BB PCM63K and one CS8414, what's the best digital filter chip?

TIA
Felipe

 

[Joschl]

PMD100 would be a classic choice

 

[abraxalito]

No filter chip - but build an analog filter and run NOS.

 

[merlin el mago]

PMD100 would be a classic choice

No filter chip - but build an analog filter and run NOS.

Thanks, I have the Ian NOS pcb, do you have other ideas?

 

[abraxalito]

My other ideas : if I was building a DAC with my PCM63Ks, I'd use an ARM CPU for implementing the digital filter because then I could experiment with different flavours (like linear phase, minimum phase) of filter and oversampling ratios. I'd use a discrete CFB I/V stage and then follow that with a passive filter followed by a buffer. Last in the chain would be an output trafo.

 

[merlin el mago]

Sounds interesting but for me is a little complicated because I don't know how to make filters and implement in an ARM CPU.

 

[abraxalito]

I'd be happy to share some code I wrote for filtering a few years back - have you done any assembly code programming before?

 

[merlin el mago]

Sorry, no.

 

[abraxalito]

Then I'd agree its probably rather a steep learning curve for you. But you could still make your DAC a NOS one without any kind of digital filtering.

 

[merlin el mago]

Thanks, yes I know: used for PCM1704 the Ian NOS pcb.

 

[merlin el mago]

abraxalito what digital filter do you recommend or do you believe is better going NOS. Not pleased with pcm1704 NOS sound.

 

[mbrennwa]

Hi guys,

I'm trying to make a DAC for my CD transport, I have two BB PCM63K and one CS8414, what's the best digital filter chip?

TIA
Felipe

NPC5843A, like in the good old Stokes DAC.

 

[merlin el mago]

NPC5843A, like in the good old Stokes DAC.

Thanks, do you compared the sounds quality vs PMD100 or DF1704 or others?

 

[abraxalito]

abraxalito what digital filter do you recommend or do you believe is better going NOS. Not pleased with pcm1704 NOS sound.

When I experimented with an ARM-implemented 2X OS filter (minimum phase) I found I preferred NOS. I haven't yet found a digital filter I would recommend as they all tend to be 8X OS (SAA7220 excepted) and I'd suggest using no more than a 2X oversampling filter as this gives plenty of frequency domain room to implement an analog anti-imaging filter.

What were you using for I/V when you didn't like the PCM1704 sound? I've heard that PCM63 sounds a bit better than PCM1704.

 

[merlin el mago]

Is not NOS sound related.

PCM1704 sounds with a lot of information but thin.

PCM63 sounds with less resolution but the sound is OK for my taste: not to much or less of bass/mids/treble so well balanced and mids to die for.

 

[merlin el mago]

As I/V I used Erno Borbely stuff:

EB-201/214/DAC13 ALL FET I/V CONVERTER & FILTER FOR DACS
(Teflon PCB, Black Gates, Caddock, Welwyn RC55)

EB202/254 ALL FET DUAL LOW-NOISE REGULATOR 5uV NOISE
(Teflon PCB, Panasonic FM & FC, Dale RN60)

EB-1198/309 PSU
(4 Nichicon KG Gold Tune 10.000uF 35V, delay)

EB-802/259 TOROIDAL POWER TRANSFORMER
Prim I 50VA 115V
Prim II 115V
Sec I 0,50A 22V-0-22V
Sec II 0,50A 22V-0-22V
Sec III 0,50A 0-12V

 

[mbrennwa]

Thanks, do you compared the sounds quality vs PMD100 or DF1704 or others?

No.

 

[merlin el mago]

No.

Thanks for let me know.

 

[abraxalito]

EB-201/214/DAC13 ALL FET I/V CONVERTER & FILTER FOR DACS
(Teflon PCB, Black Gates, Caddock, Welwyn RC55)

Tried to search for the schematics of this but failed - borbelyaudio.com seems not to be responding. If its using passive I/V then the DAC power supply becomes extremely critical. These days I don't recommend passive I/V for this reason.

Save​

 

[mlloyd1]

borbely's site was closed down some years ago when he retired.
most of the material is available via "the wayback machine".

mlloyd1