Thanks, intresting, wordlength shouldn't matter. So I do get a solid green light, but no red, and clockrate at the console ouput.
What could be the problem?
Btw, I just measured DC off-set at the XLR output, 2Vdc..., that is a bit much and would explain some of the popping.
Last edited:
ESS9018...
So Delta-sigma ESS9018 is winning the race again. I know one might think about implementation but I increasingly see r2r beaten by Delta-sigma in their respective best implementations. If one take out MSB/TotalDAC then it is Delta-sigma that is currently ruling the high-end; even where money is no object. Even dCS is kind of Delta-sigma.
I think there is something wrong with my love of NOS TDA1541A,
So Delta-sigma ESS9018 is winning the race again. I know one might think about implementation but I increasingly see r2r beaten by Delta-sigma in their respective best implementations. If one take out MSB/TotalDAC then it is Delta-sigma that is currently ruling the high-end; even where money is no object. Even dCS is kind of Delta-sigma.
I think there is something wrong with my love of NOS TDA1541A,
got a new amanero
popping seems worse with it than my last one
seems weird
probably wouldn't do any harm but it's uncomfortable
hard to understand the dams led is blinking and locks there's no sound
have you another i2s source just to check
takes a bit of work to get any dac to sound good (sigma delta ess 9018 or otherwise)
tweakability value for money not a bad place to start
popping seems worse with it than my last one
seems weird
probably wouldn't do any harm but it's uncomfortable
hard to understand the dams led is blinking and locks there's no sound
have you another i2s source just to check
takes a bit of work to get any dac to sound good (sigma delta ess 9018 or otherwise)
tweakability value for money not a bad place to start
Thanks Nige, I have other I2S sources but they are in my other dac which I don't want to cannibalise just yet. Others have gotten the RPi to work so it is possible, I just need to figure out how.
Strange the Amanero is behaving differently, it's firmware upgradeble. Maybe your running different images.
I would order the DIYINHK USB board if only HK Post didn't take three weeks.
Strange the Amanero is behaving differently, it's firmware upgradeble. Maybe your running different images.
I would order the DIYINHK USB board if only HK Post didn't take three weeks.
I get exactly the same popping-behaviour with the amanero, the optical input or the coax input. The amount of popping depends (with me) only on the signal played in the first few seconds after sample rate change (minor pop with silence, more pop with music).
So Delta-sigma ESS9018 is winning the race again. I know one might think about implementation but I increasingly see r2r beaten by Delta-sigma in their respective best implementations. If one take out MSB/TotalDAC then it is Delta-sigma that is currently ruling the high-end; even where money is no object. Even dCS is kind of Delta-sigma.
I think there is something wrong with my love of NOS TDA1541A,
Have you ever compared your loved TDA1541A (well implemented) with the ESS9018? Or a well implemented AD1865?
If not, you should do that.
And surprise you that a dac from 80's sounds better than the iper technological last generation Sabre.
And try to think because Philips and AD stopped the production of such jewels.
Or try to think because a pair of PCM1704 cost so much.
Cost, cost, cost again. Delta-Sigma are much much cheaper to manufacture.
R2R dac are complex and their manufacture process is very expensive.
Delta-Sigma dac shift the issue of the resolution in time domain, so while get resistor better then 0.01% is really difficult, a clock of 0.0000005% is relatively easy.
Translate voltage to time, and magically you reach 24 bit resolution.
Last but not least, keep in mind that using 0.01% resistors tolerance you can reach not more than 13-14 bit precision, regardless of the notation used to represent data:
1/8182 = 0.000122, or let's say 0.01%, or let's say again 13 bit.
Neither the PCM1704 (nor the DAM 1021) are that what you find e.g. in Wikipedia as R2R DAC, with that 100000.... to 0111111.... switch example which, for R2R DACs, links the resistor precision to the resolution.
Both are sign magnitude DACs, consisting of two R2R networks (each of one bit less) taking care of the positive respectively negativ part of the signal. One reason for this more complex design is to overcome the above limitation.
Electrical engineers are not that stupid to build a "24-bit" DAC with only 13 bit precision
Last edited:
Neither the PCM1704 (nor the DAM 1021) are that what you find e.g. in Wikipedia as R2R DAC, with that 100000.... to 0111111.... switch example which, for R2R DACs, links the resistor precision to the resolution.
Both are sign magnitude DACs, consisting of two R2R networks (each of one bit less) taking care of the positive respectively negativ part of the signal. One reason for this more complex design is to overcome the above limitation.
Electrical engineers are not that stupid to build a "24-bit" DAC with only 13 bit precision
As Søren has pointed out the DAM is not a straight R-2R DAC, but rather a Segmented DAC.
It's worth having a read of this Analog Devices tutorial. At least one example is pretty close to the DAM as far as I can tell.
http://www.analog.com/media/en/training-seminars/tutorials/MT-016.pdf
Last edited:
The "segmented" is only an different implementation for the most significant bits. It "solves" the problem that the MSB-part has to handle most of the power. This can be applied for an R2R-like DAC (1 ladder) or a Sign-Magnitude (R2R)-DAC (2-ladders).
The important thing is the Sign-Magnitude implementation, as it frees us from the problems with the resistor tolerances with the least significant bits and thus allows to build DACs with more (meaningfull) bits.
Last edited:
not what I meant
do you think the raw output got better with omamp removal
No, I couldn't recognize any improvement to my old&poor ears
I think it's OK as I wanted to reduce the battery life.
---
Kohjin
Neither the PCM1704 (nor the DAM 1021) are that what you find e.g. in Wikipedia as R2R DAC, with that 100000.... to 0111111.... switch example which, for R2R DACs, links the resistor precision to the resolution.
Both are sign magnitude DACs, consisting of two R2R networks (each of one bit less) taking care of the positive respectively negativ part of the signal. One reason for this more complex design is to overcome the above limitation.
Electrical engineers are not that stupid to build a "24-bit" DAC with only 13 bit precision
I think there is a little confusion between resolution and precision (or monotonicity, if you prefer).
And the Sign Magnitude is simply a different notation to represent data, that avoid to switch the MSBs if not needed. There is nothing related to the precision.
You can build a R-2R ladder with 64 resistors, and there is no doubt you reach 64 bit resolution.
But using 0.01% resistors tolerance, you reach the same 13-14 bit precision, regardless of the notation used. That's the reason why Philips used DEM in his TDA1541A, and Burr Brown used 0.001% (or better) laser trimmed resistor on chip in his PCM63/PCM1704. The precision of the PCM1704 is 17 bit, while its resolution remain 24 bit.
In a discrete R-2R ladder dac there are also other issues: temp drift of the resistors, aging of the resistors, resistance of the switches (13 ohm!!), and so on.
I explained this several times in this thread, with mathematical example:
do you agree that with 8192 (2 exp 13) step you can represent 13 bit?
if yes, you can calculate the ratio: 1/8192 = 0.000122
since resistor tolerance is given in percent, you can multiply 100 times:
0.000122 * 100 = 0.0122%
that's the resistors tolerance needed to reach 13 bit precision, or precisely a little more than 13 bit, but below 14 bit.
And again there is nothing correlated with the notation, since when the 14th bit will switch you loose half 1 bit of precision, on the 15th bit you loose 1 more bit and so on.
So you have a perfect 13 bit dac until the dynamic of the music is constricted within 13 bit.
Using 2 separate ladders for each channel (that's not the best practice, Burr Brown used a single ladder in their PCM63 and PCM1704), you can add 1 bit of precision, to reach 14 bit.
But if you own a different engineering explanation, I will be glad to learn.
Last edited:
I thought about the shootout conducted by TNT and his gang.
I don't want to discuss that it is kind of useless to me (apples and oranges and a potentially rather weak implementation of the DAM).
However. Obviously the Sabre protoype performed ways better than any
other DAC. That doesn't really surprise me.
The Sabre 9018 is known, if properly implementend, with clean I2S signal, with current output, good outputstage, good PS and several great regulators, the right choice of clock, paralleled outputs, asf.asf. to deliver more fine details (higher precicison ?) than pretty much any other DAC out there.
Some like it, others prefer the more "natural" (whatever that means) sound that comes with other DACs.
If've been running a DDDAC1543 for a couple of years (I also ran a TP Buffalo afterwards btw.). That DDDAC also had a passive voltage output.
During the years running the DDDAC I tried all kind of output resistors. They all sounded different.
I ended up with a resistor from Rhopoint, which showed far more "details" in the sound then any other resistor I tried.
And that resistor didn't even have a 0.01% tolerance btw. To me the conclusion at that time was: One of the key elements of that DAC implementation was the right choice
of resistor for the passive voltage-output.
Today I read that the TotalDAC uses Vishay 0.01% VAR Bulk Metal foil resistors, which - as far as I recall discussions over here at DIYA - also perform extremely well as passive voltage-out resistors.
I'm wondering if the choice of resistors - despite its tolerance - in the ladder of the DAM could have a serious impact to the experienced "details" in sound.
The wrong choice of resistors might even be a limiting factor.
I don't know how Soeren selected the type of resistors he's using. I'd assume he has done his homework.
But. It would be nice to know how he has selected the type of resistors he is using and how they'd compare to e.g. the Vishays as used in the TotalDac.
Abother subject:
@andrea_mori: could you please refer to an article/site which describes how the "tolerance" of a resistor impacts the "precision" of a ladder dac. THX.
I don't want to discuss that it is kind of useless to me (apples and oranges and a potentially rather weak implementation of the DAM).
However. Obviously the Sabre protoype performed ways better than any
other DAC. That doesn't really surprise me.
The Sabre 9018 is known, if properly implementend, with clean I2S signal, with current output, good outputstage, good PS and several great regulators, the right choice of clock, paralleled outputs, asf.asf. to deliver more fine details (higher precicison ?) than pretty much any other DAC out there.
Some like it, others prefer the more "natural" (whatever that means) sound that comes with other DACs.
If've been running a DDDAC1543 for a couple of years (I also ran a TP Buffalo afterwards btw.). That DDDAC also had a passive voltage output.
During the years running the DDDAC I tried all kind of output resistors. They all sounded different.
I ended up with a resistor from Rhopoint, which showed far more "details" in the sound then any other resistor I tried.
And that resistor didn't even have a 0.01% tolerance btw. To me the conclusion at that time was: One of the key elements of that DAC implementation was the right choice
of resistor for the passive voltage-output.
Today I read that the TotalDAC uses Vishay 0.01% VAR Bulk Metal foil resistors, which - as far as I recall discussions over here at DIYA - also perform extremely well as passive voltage-out resistors.
I'm wondering if the choice of resistors - despite its tolerance - in the ladder of the DAM could have a serious impact to the experienced "details" in sound.
The wrong choice of resistors might even be a limiting factor.
I don't know how Soeren selected the type of resistors he's using. I'd assume he has done his homework.
But. It would be nice to know how he has selected the type of resistors he is using and how they'd compare to e.g. the Vishays as used in the TotalDac.
Abother subject:
@andrea_mori: could you please refer to an article/site which describes how the "tolerance" of a resistor impacts the "precision" of a ladder dac. THX.
Last edited:
Just do it, please take a look at post #320
http://www.diyaudio.com/forums/vend...te-r-2r-sign-magnitude-24-bit-384-khz-32.html
"The required accuracy doubles with each additional bit—for 8 bits, the accuracy required will be better than 1/256 (0.4%). Within integrated circuits, high accuracy R-2R networks may be printed directly onto a single substrate using thin-film technology, ensuring the resistors share similar electrical characteristics. Even so, they must often be laser trimmed to achieve the required precision. Such on-chip resistor ladders for digital-to-analog converters achieving 14 bits accuracy have been demonstrated. On a printed circuit board, using discrete components, resistors of 1% accuracy would suffice for a 5 bit circuit, however with bit counts beyond this the cost of ever increasing precision resistors becomes prohibitive. For a 10 bit converter, even using 0.1% precision resistors would not guarantee monotonicity of output"
Have you any idea about the cost of 0.01% Vishay metal foil resistor?
If yes, then you can understand why TotalDac is so expensive, while other R-2R dac are so cheap.
And keep in mind that the accuracy is the same: 0.01% ---> 13/14 bit.
I do not understand what kind of precision is meant (Because I probably do not understand the math behind it)
But I did a simple test with the dam... I can attenuate a full scale 1k sine tone at least 110 dB and I still can see the tone on the analyzer. Looks like a clean 1k tone. That is more than 18 bit down from full scale... how can that happen if max precision is 14 bit. Or is, what I measured, resolution and precision is something else?
The attached application note clearly explains the difference between resolution and accuracy (or precision).