Hi All,
In the near future DVD-A will probably be more popular than the 'older' audio CD. With DVD machine prices crashing it seems inevitable. DVD-A disc prices however may be the deciding factor.
For the DIY'ers , is there any chip that decodes 24 /96 as well as our old TDA1541A for 16/44.1 ? Basically that means is there any 24/96 chip equivalent to the TDA1541A in performance.
There aren't too many manufacturers and so the list of chips must be limited. Can anyone comment on a 'known good chip'.
Thanks.
Cheers.
In the near future DVD-A will probably be more popular than the 'older' audio CD. With DVD machine prices crashing it seems inevitable. DVD-A disc prices however may be the deciding factor.
For the DIY'ers , is there any chip that decodes 24 /96 as well as our old TDA1541A for 16/44.1 ? Basically that means is there any 24/96 chip equivalent to the TDA1541A in performance.
There aren't too many manufacturers and so the list of chips must be limited. Can anyone comment on a 'known good chip'.
Thanks.
Cheers.
This is of interest to me too
I am also looking for a really musical, but realistically simple DAC to accept SPDIF and I2S inputs to fit into a CDP/DAC/Preamp project.
I have looked at the data sheets for the PCM1704 from TI, and I think that that could be manageable, providing someone with more talent with me can design and manufacture PCBs based on the data sheet.
This is the DAC used in the latest NAIM players and by all accounts is a great piece of kit.
I am also looking for a really musical, but realistically simple DAC to accept SPDIF and I2S inputs to fit into a CDP/DAC/Preamp project.
I have looked at the data sheets for the PCM1704 from TI, and I think that that could be manageable, providing someone with more talent with me can design and manufacture PCBs based on the data sheet.
This is the DAC used in the latest NAIM players and by all accounts is a great piece of kit.
how could we forget.....
Ashok,
I understand your question... as you can probably guess, I am in no position to give you an answer!!!
This exercise is so challenging, partly because swapping DACs in the same circuit may not give optimised results. I've been looking at replacing the DAC in my Marantz CD42 for years now, and am still no closer to coming up with a definitive answer e.g. does one go for transformer coupled outputs, tube buffers, 5th order bessel filters, GIC filters??? And that's just the output stage...
Sorry this has been such a useless answer, and good luck!
Arnie
I understand your question... as you can probably guess, I am in no position to give you an answer!!!
This exercise is so challenging, partly because swapping DACs in the same circuit may not give optimised results. I've been looking at replacing the DAC in my Marantz CD42 for years now, and am still no closer to coming up with a definitive answer e.g. does one go for transformer coupled outputs, tube buffers, 5th order bessel filters, GIC filters??? And that's just the output stage...
Sorry this has been such a useless answer, and good luck!
Arnie
By the way, I'de be interested in that thread too. I have built a DAV with TDA1545 which sounds fantastic, and a friend has very good results with AD1875 (which shows even more potential, maybe...)
So is there a chip that sounds as good as the good old Multibits, while taking 24-96 ?
There is PCM1704, never heard it though...
So is there a chip that sounds as good as the good old Multibits, while taking 24-96 ?
There is PCM1704, never heard it though...
Re: Whaddya mean......
Jocko,
Many people feel the PCM63 was the best of all those BB
DAC's. We used the '63 and disabled bipolar offset internal
compenasation current (2mA) and found significant improvement.
This is a worry WRT the 1704 as you can't disable it. However
the 1704 does measure slightly better. Have you done direct
comparison with 63 and 1704???
What DF did you use, we used PMD100 (HDCD) and now are
looking at running 63 in 0 x OS
The PMD100 has great detail and resolution but I think it
may be a bit unmusical. I remember trying DF1704 and there
was mixed opinion compared to PMD100..... it's a can of worms!
Terry
Jocko Homo said:
Jocko,
Many people feel the PCM63 was the best of all those BB
DAC's. We used the '63 and disabled bipolar offset internal
compenasation current (2mA) and found significant improvement.
This is a worry WRT the 1704 as you can't disable it. However
the 1704 does measure slightly better. Have you done direct
comparison with 63 and 1704???
What DF did you use, we used PMD100 (HDCD) and now are
looking at running 63 in 0 x OS
The PMD100 has great detail and resolution but I think it
may be a bit unmusical. I remember trying DF1704 and there
was mixed opinion compared to PMD100..... it's a can of worms!
Terry
Folded cascode
Thanks to all for your replies.
Hi Peufeu,
Can you post your folded cascode design ? I can build it and compare it with my resistor loaded TDA1541 output. I have been looking for alternative solutions but never could decide on one. I also agree that the ideal situation would be to have a virtual zero ohm load at the current output .My load is 50 ohms but might make an audible difference if that was a virtual zero. Reducing the load to 10 ohms would be throwing away precious signal.
Will be waiting to see your folded cascode solution.
Cheers.
Thanks to all for your replies.
Hi Peufeu,
Can you post your folded cascode design ? I can build it and compare it with my resistor loaded TDA1541 output. I have been looking for alternative solutions but never could decide on one. I also agree that the ideal situation would be to have a virtual zero ohm load at the current output .My load is 50 ohms but might make an audible difference if that was a virtual zero. Reducing the load to 10 ohms would be throwing away precious signal.
Will be waiting to see your folded cascode solution.
Cheers.
Re: Re: Re: Whaddya mean......
Jocko,
We went away from R I-V years ago because the '63 has more
distortion with increased OP compliance. You can directly
compare this by using a good OPA I-V with something like a
627 and add varying resistance in front of it to simulate an R
I-V. The '63 starts to change it's sound with as little as 15R.
WRT Folded Cascode topology, I agree. We have built many of
those cascode I-V's in various topologies with Jfets, BJT's MOS,
complementary, SE, folded, CFP, non CFP, etc etc.
However to answer your question, when we first checked the BPO
phenomenom it was with discrete CFB opamp I-V (closed loop).
There was no voltage swing at dac OP, and it still degraded the
sound, quite strange.
Terry
peufeu said:
Jocko,
We went away from R I-V years ago because the '63 has more
distortion with increased OP compliance. You can directly
compare this by using a good OPA I-V with something like a
627 and add varying resistance in front of it to simulate an R
I-V. The '63 starts to change it's sound with as little as 15R.
WRT Folded Cascode topology, I agree. We have built many of
those cascode I-V's in various topologies with Jfets, BJT's MOS,
complementary, SE, folded, CFP, non CFP, etc etc.
However to answer your question, when we first checked the BPO
phenomenom it was with discrete CFB opamp I-V (closed loop).
There was no voltage swing at dac OP, and it still degraded the
sound, quite strange.
Terry
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