Some commercial DAC’s are designed to upsample everything to for example 24/192 before it is fed to the DAC chip so it would be easier to design a filter after it.
As the ES9023 has an integrated buffer that can drive line out direct I am not sure how to get the best result from the DAC.
Does the DAC perform better if I offer native resolution like 44.1 or should I upsample first to 176.4 / 192 ?
There is not much information on the available datasheet.
And is there any benefit putting some extra circuity after line Line-Out like additional buffer or filter ?
My pre-amp is 500k input and use 50cm low capacitance interlinks so my first impression would be to drive it direct.
FYI: I use this Sellarz DAC board:
As the ES9023 has an integrated buffer that can drive line out direct I am not sure how to get the best result from the DAC.
Does the DAC perform better if I offer native resolution like 44.1 or should I upsample first to 176.4 / 192 ?
There is not much information on the available datasheet.
And is there any benefit putting some extra circuity after line Line-Out like additional buffer or filter ?
My pre-amp is 500k input and use 50cm low capacitance interlinks so my first impression would be to drive it direct.
FYI: I use this Sellarz DAC board:
Thanks.
About the upsampling I meant many DAC chips need a low pass filter in the analogue stage.
To avoid a brick wall filter with the related phase problems some commercial DAC's are designed to upsample everything first to 24/192 to move the garbage up in the frequency band so the low pass filter can be less steep avoiding phase shift in the audio band.
But reading more about the ES9023 I guess this type of (add on) filter is not needed or not an issue with the line out from the chip direct ?
In that case my question was not relevant to this DAC design.
About the upsampling I meant many DAC chips need a low pass filter in the analogue stage.
To avoid a brick wall filter with the related phase problems some commercial DAC's are designed to upsample everything first to 24/192 to move the garbage up in the frequency band so the low pass filter can be less steep avoiding phase shift in the audio band.
But reading more about the ES9023 I guess this type of (add on) filter is not needed or not an issue with the line out from the chip direct ?
In that case my question was not relevant to this DAC design.
Yes, you don't need to worry. The 2 x 4.7 nF filter film caps at the outputs are enough. With low impedance loads the situation changes. My experiments with output stages did not bring much. I never tried out the Joachim Gerhard output stage though. It is supposed to enhance sound quality.
What I wanted to try is a tube buffer and parts are in stock and PCB design is ready but till now I haven't had the boards made.
What I wanted to try is a tube buffer and parts are in stock and PCB design is ready but till now I haven't had the boards made.
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As I use the DAC with a BeagleBone Black (I2S direct) all 44.1 and mltiples are downsampled by default to 48k family because of the BBB onboard clock of 24.576.
http streams, MP3 and 44.1 are all downsampled to 32k.
I set mpd.conf to resample everything to 96k and this already sounds better.
Therefore also my interest in the possible gains upsampling everything by default ... also later as soon as I have connected my external Tentlabs 16.934 clock for 44.1/88.2 music together with the Botic driver.
http streams, MP3 and 44.1 are all downsampled to 32k.
I set mpd.conf to resample everything to 96k and this already sounds better.
Therefore also my interest in the possible gains upsampling everything by default ... also later as soon as I have connected my external Tentlabs 16.934 clock for 44.1/88.2 music together with the Botic driver.
It would not surprise me at all if it is more or less the same technology as used in the more expensive ESS chips but with only 2 channels. Making a complete new chip costs more than omitting features of an existing proven piece of hardware/die design. The ES9023 does not sound too shabby for a reason. It sounds way better than its price would indicate anyway. With many current products it is a habit to make a "bells and whistles" version and all lower priced versions are the same with features disabled by software etc. Way cheaper to produce.
My experiences with upsampling till now were not too positive but I read it sounds better in your config...I never bothered to resample/upsample any of my files.
BTW with all that RF emitting devices mounted on a wooden plank it would probably be wise to use shielded wires for the analog outputs. Using a lot of digital toys may let one forget some basic rules
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Yes I said it was a guess. But the filter in the more expensive chips is also probably not going to be as advanced as doing the upsampling on a PC given the huge difference in compute power. All integrated filters I've seen are half-band for example, in order to save on multiplies - no such constraint needs be applied to a software filter.
A small sidestep but still related.
If I would upsample everything I guess I better use 176.4 for 44.1 / 88.2 and 192 for 96 / 48 files ?
This way I have the impression I am keeping in sync with the actual sample rate of the file.
I realise I better use a 22.579 clock for higher fs factor on 44.1 family as my current Tentlabs use a relatively slow 16.934 XO.
I am not sure how to achive 2 different upsample values in mpd.conf but that is another matter ;-)
If I would upsample everything I guess I better use 176.4 for 44.1 / 88.2 and 192 for 96 / 48 files ?
This way I have the impression I am keeping in sync with the actual sample rate of the file.
I realise I better use a 22.579 clock for higher fs factor on 44.1 family as my current Tentlabs use a relatively slow 16.934 XO.
I am not sure how to achive 2 different upsample values in mpd.conf but that is another matter ;-)
BTW with all that RF emitting devices mounted on a wooden plank it would probably be wise to use shielded wires for the analog outputs. Using a lot of digital toys may let one forget some basic rules
Of course, this is only my intermediate breadboard before I start putting it in a real enclosure.
Stil need to connect the Tentlabs clock and now everything is easy accesible to make sure it works as expected.
In the metal enclusure I plan to make compartments sheelding analogue from digital.
This is my "build topic" about this project: http://www.diyaudio.com/forums/pc-based/286943-beaglebone-black-externbal-i2s-clock.html
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BTW with all that RF emitting devices mounted on a wooden plank it would probably be wise to use shielded wires for the analog outputs. Using a lot of digital toys may let one forget some basic rules
Some time has past already but finally yesterday I put the DAC board in an aluminium enclosure which is put in a bigger enclosure.
Like having a vault in a building ;-)
This way the DAC board is isolated from most HF radiation, I even put a ferrite core around the I2S signal cables.
The P/S modules are only for the time being, for the BBB I will build a better regulator and the DAC board will be fed by a 2 sets of 18650 Li-on batteries (one charge; the other discharging and vice-versa to have the DAC completely isolated from the power supply.
Short story: from wood to aluminium ... enjoy the pictures
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