I've just fired up my PCM2DSD module and listening to some nice music 😊 Thanks Pjotr and Olo.
I'm just doing a basic test using a USB OTG connection from my smartphone (running USB Audio Pro) as the source and my simple RC filter as the decoder, playing through my Noir headphone amp. Anyway, it obviously works and sounds pretty good. Firmware is not the newest version so I may have to speak nicely to @Cestrian and get him to reflash the board with the latest version.
I'm using one of these as my 'Amanero'.
I'm just doing a basic test using a USB OTG connection from my smartphone (running USB Audio Pro) as the source and my simple RC filter as the decoder, playing through my Noir headphone amp. Anyway, it obviously works and sounds pretty good. Firmware is not the newest version so I may have to speak nicely to @Cestrian and get him to reflash the board with the latest version.
I'm using one of these as my 'Amanero'.
These seem to be limited by DSC 2.5.2. Do you have measurements with something that measures better (AKM/ESS)?
In general, yes. Don't use DSC, but have an Andrea Mori discrete resistor DSD dac.
IIUC that was at least in part about trading off allocation of limited resources in the FPGA.
Merlin, the whole system plays, from what I remember you don't have a DAC, only "Pure DSD" = RC filter? Maybe that's the problem...
You have poor filtering...
To be more specific, I meant how PCM2DSD fares with those. Because Miska of HQPlayer claims that AKM is better with 7th order and ESS with 5th order.
Looks like ESS does something to convert DSD to maybe something like PCM or PCM-narrow so that the digital volume control can work. Don't know what it does with the signals from there, whether it remodulates them differently from or something as compared to whatever it does with PCM.
AKM can do more or less the same as ESS, or the digital volume control can be bypassed and DSD sent directly to the internal output stage.
Doesn't seem especially remarkable that there could be differences in how the various downstream processing affects the sound.
That said, SQ as function of filter order isn't necessarily that simple. There are some graphs of DSD filters of various orders at: https://pcmdsd.com/Software/PCM-DSD_Converter.html (it may help to use google chrome browser with translation enabled.) I have heard several of those DSD converters. They all sound different. The 7th order converter you can download from <the English language version of> that site is not bad except for the that center of the soundstage is a little weak/low-level, like maybe there a slight phase problem between the two channels. Something like that. Don't think it especially has anything to do with 5th order or 7th order. Maybe something specific to the particular implementation.
AKM can do more or less the same as ESS, or the digital volume control can be bypassed and DSD sent directly to the internal output stage.
Doesn't seem especially remarkable that there could be differences in how the various downstream processing affects the sound.
That said, SQ as function of filter order isn't necessarily that simple. There are some graphs of DSD filters of various orders at: https://pcmdsd.com/Software/PCM-DSD_Converter.html (it may help to use google chrome browser with translation enabled.) I have heard several of those DSD converters. They all sound different. The 7th order converter you can download from <the English language version of> that site is not bad except for the that center of the soundstage is a little weak/low-level, like maybe there a slight phase problem between the two channels. Something like that. Don't think it especially has anything to do with 5th order or 7th order. Maybe something specific to the particular implementation.
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AK4191 can also do digital volume control on DSD input by converting to multibit.
From the HQPlayer manual: "Fifth order modulators are more suitable for DACs that have simple analog reconstruction filters. Seventh order modulators provide better technical performance, but also put more demands on the DAC's analog reconstruction filter. Typically this means that fifth order modulators suit DACs that have one switching element while seventh order modulators have potential for better performance on DACs that have multi-element switching arrays. [...] For ESS Sabre based DACs, fifth order modulators are recommended. For most other DACs, seventh order modulators are optimal."
Hence my question, when you say you have auditioned several versions, if you also auditioned on different hardware.
Currently in the works of gathering materials for my own PCM2DSD build for my AK4499EQ DAC. So I can A/B 5th versus 7th order on this DAC myself later this year. Today interested in hearing A/B listening impressions of you guys, if you can share. Using HQPlayer I honestly cannot tell the difference between 5th and 7th order.
From the HQPlayer manual: "Fifth order modulators are more suitable for DACs that have simple analog reconstruction filters. Seventh order modulators provide better technical performance, but also put more demands on the DAC's analog reconstruction filter. Typically this means that fifth order modulators suit DACs that have one switching element while seventh order modulators have potential for better performance on DACs that have multi-element switching arrays. [...] For ESS Sabre based DACs, fifth order modulators are recommended. For most other DACs, seventh order modulators are optimal."
Hence my question, when you say you have auditioned several versions, if you also auditioned on different hardware.
Currently in the works of gathering materials for my own PCM2DSD build for my AK4499EQ DAC. So I can A/B 5th versus 7th order on this DAC myself later this year. Today interested in hearing A/B listening impressions of you guys, if you can share. Using HQPlayer I honestly cannot tell the difference between 5th and 7th order.
I have a custom AK4499EQ dac. Tried various DSD modulators with it, although didn't try it with the one of this thread. Did try it with AK4499EXEQ though. Both dacs were always operated in volume bypass mode. What I found was that the Vref supply had more effect on the sound than the modulator order. Even with Vref as good as I ever got it, haven't heard an IC dac with overall better SQ than a good discrete resistor dac. That said, IME IC dac chips may be able to sound smoother at HF when playing DSD (maybe because of their internal output stage DEM/DES).
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Not right, I have a 4th order LPF with enough corner frequency followed with an amorphous step-up transformer. The difference in SQ without or with your PCB is day & night. Also telling the same SQ as HQPlayer isn't true.
What does that mean? If you are using the FPGA DSD converter in DSD bypass mode then you still don't like it? If so, what do you think its doing in that case that's different from not having it the circuit?
Also, one of the things I'm wondering about is if you send a dac DSD then likely your OS would not mess with it. However if you send your dac PCM then your OS just might be doing something to the data. Have you done tests to show that PCM is transmitted to the FPGA dsd converter in bit-perfect form? If not, how do you know the OS is not a problem?
Not saying you're doing something wrong, just asking what you have checked and how you checked it to make sure some of the things OS have been known to do with PCM has been carefully ruled out.
Thanks for the clarifification, Felipe, I was under the impression you were still using the simple No-DAC approach - apologies.
It's a fantastic project
@Pjotr25
Do you consider adding HDMI output to the board for easy connection with various DACs? There are plenty of inexpensive HDMI connectors available. Since xc6slx09 has several LVDS outputs, connecting it with just a connector is possible. I am currently connecting my D90 (ak4499eq) through HDMI to verify the analog output. As DACs with HDMI inputs are becoming more common, I believe it would be a worthwhile investment.
@Pjotr25Do you consider adding HDMI output to the board for easy connection with various DACs? There are plenty of inexpensive HDMI connectors available. Since xc6slx09 has several LVDS outputs, connecting it with just a connector is possible. I am currently connecting my D90 (ak4499eq) through HDMI to verify the analog output. As DACs with HDMI inputs are becoming more common, I believe it would be a worthwhile investment.
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I'm sorry I don't want to be rude Pjtor25 & Olo, big thanks for your work & share to the DiyAudio community. Please be so kind to tell me what's the best implementation, thanks?