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146.90.135.90
In Reply to: RE: You do understand posted by E-Stat on August 22, 2018 at 05:51:46
With that number in use . . .
Sorry, my mistake. My DDDAC has a mere 18 TDA1543s. I must have been carried away by pix on the designer's web site of 48- and 64-way versions (chip porn?).
That said, a reclocking board design published by Ian-from-Canada on DIY-Audio reportedly allows the TDA1541A to run happily at 384/24 despite its datasheets saying it's limited to 96/16.
D
Follow Ups:
The TDA1541a can operate at 8x oversampling so Ian took advantage of that with his board by running the TDA1541a in simultaneous mode to allow 384kHz. His board accepts 24 bit depth but the TDA1541a is only capable of 16 bits so the last 8 bits are discarded by the TDA1541a.
His board accepts 24 bit depth but the TDA1541a is only capable of 16 bits so the last 8 bits are discarded by the TDA1541a.
Thanks for that - makes sense.
D
if you wish to decode 'Brownian noise' at 144.49 dB
.
That said, a reclocking board design published by Ian-from-Canada on DIY-Audio reportedly allows the TDA1541A to run happily at 384/24 despite its datasheets saying it's limited to 96/16.When used in multiples, one can extend word size of a given chip or improve S/N ratio. My Audio Research DAC8 uses four 24 bit mono DACs for the latter reason.
You could overclock the bejesus out of it, but I suspect you won't find commercial products that attempt such.
edit: Restructured post so there is no question!
Edits: 08/22/18
I owned a Cary CD 306/200 CDP many years ago. It was an awesome sounding CDP that used eight Burr Brown 1704 DAC chips (four for each channel).
- Two chips in parallel for the + side, and two chips in parallel for the - side of one balanced output channel.Replicate the above for the other channel for a total of 8 DAC chips.
Cary says they paralleled the DAC chips to further improve S/N ratio.
Edits: 08/22/18 08/22/18
with ARC using Texas Instruments PCM1792As .
Stereophile!
"Theta's general manager Jim White agreed, describing the new DAC as "absolutely, without question, the best." In a telephone interview July 24, White mentioned that Theta will soon ship a new digital processor, the DS Pro Generation VI, which will include four PCM 1704 DACs "for fully balanced operation." The Gen.VI will retail "in the $6000 range," White said;"
Link below:
Same as my Audio-GD Master 7.
Balanced from the output of the USB> I2S AMANERO board to the audio out balanced jacks.
Decent sound but REALLY large and heavy.
I didn't think the PCM1704 was a ladder DAC?? That Audio-GD Master 7 of yours is a beast! Is it's claim to fame outstanding sound from the older DAC chip?
Edits: 08/22/18
yes
especially now that the 1704 chip is hard to find
Alan
"The R-2R ladder utilizes dual balanced current segments to
ensure ideal tracking under all conditions. By interleaving
the individual bits of each DAC and employing precision
laser-trimming of resistors, a highly accurate match between
the two DACs is achieved."
Laser trimmed, no less.
Last Mauser price I saw a year or two ago was $75 each.
There is no longer stock so Audio-GD has gone back to DACs using real resistors.
I don't know why, but I often see erroneous posts about the PCM1704 no longer being available. It is just not true.
TI still sets up the line every few years and runs 200,000 or so. It is a pain for them as the fab equipment used is getting really long in the tooth. While they only label them as -U or -UJ, they pretty much all test at the level of the original -K.
And oh yeah, they charge a lot more for them than in decades past.
Richardson generally keeps the most stock--and I find them convenient--but there are other sources around the world.
https://www.rocelec.com/part/TEXTISPCM1704U-J
...a R2R ladder DAC after all per the link you provided. Thanks.
PCM1704 THEORY OF OPERATION
SIGN-MAGNITUDE ARCHITECTURE
Digital audio systems have traditionally used laser-trimmed,
current-source DACs in order to achieve sufficient accuracy.
However, even the best of these suffer from potential low-
level nonlinearity due to errors in the major carry bipolar
zero transition. Current systems have turned to oversampling
data converters, such as the popular delta-sigma architec-
tures, to correct the linearity problems. This is done, how-
ever, at the expense of signal-to-noise performance, and the
noise shaping techniques utilized by these converters creates
a considerable amount of out-of-band noise. If the outputs
are not properly filtered, dynamic performance of the overall
system will be adversely effected.
The PCM1704 employs an innovative architecture which
combines the advantages of traditional DACs (e.g., excellent
full-scale performance, high signal-to-noise ratio, and ease
of use) with superior low-level performance. This architec-
ture is referred to as sign-magnitude. Two DACs are com-
bined in a complementary arrangement to produce an ex-
tremely linear output. The two DACs share a common
reference, and a common R-2R ladder for bit current sources.
The R-2R ladder utilizes dual balanced current segments to
ensure ideal tracking under all conditions. By interleaving
the individual bits of each DAC and employing precision
laser-trimming of resistors, a highly accurate match between
the two DACs is achieve
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