Does this mean that PCM playback suffers or is lacking compared to DSD playback? 😕 In an earlier post you also showed THD - but only with a DSD signal. For many though, it will still mostly be PCM material playing through the dac I think - also in the years to come. 🙂 BTW will it be possible to attenuate the PCM signal in the digital domain when playing 16 or 24 bit (out of 32 bit)?
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In reality, yes PCM lacks in performance compared to the DSD.
PCM Data path goes through Digital attenuator, Interpolator, Delta sigma modulator and Switched capacitor filter.
DSD normal path goes through Digital attenuator, Delta sigma modulator and Switched capacitor filter.
DSD volume bypass path goes only through Switched capacitor filter.
I am working on a firmware where the mixer is enabled. This way when you change a setting in windows software (example: Jriver), MAC OS/X (Volume up and down you can set with the keyboard) and also Volumio it will set the value in the digital attenuator.
Besides of that i will shortly release a Shield where the USB interface controls an MAS6116 in balanced configuration. This shield will have single ended output as well as balanced output. I am working on it today.
PCM Data path goes through Digital attenuator, Interpolator, Delta sigma modulator and Switched capacitor filter.
DSD normal path goes through Digital attenuator, Delta sigma modulator and Switched capacitor filter.
DSD volume bypass path goes only through Switched capacitor filter.
I am working on a firmware where the mixer is enabled. This way when you change a setting in windows software (example: Jriver), MAC OS/X (Volume up and down you can set with the keyboard) and also Volumio it will set the value in the digital attenuator.
Besides of that i will shortly release a Shield where the USB interface controls an MAS6116 in balanced configuration. This shield will have single ended output as well as balanced output. I am working on it today.
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But that is generally speaking, right? What I wondered was if your choices / implementations made your DAC worse at playing PCM than similar / comparable DACs in the market?
It does not perform worse at all. Gain is set to 0dB meaning the digital attenuator is transparant. I have put a lot of Work into use of good isolation of the voltageregulators that ultra low noise and ultra high psrr
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Thanks a lot for taking the time to explain this. I just got the impression - wrongly I can see - that your DAC was aimed more at DSD than PCM playback. Sorry for all my questions - but I really struggle with the inner workings of dacs and (digital) audio 🙂
I like the idea of balanced configuration. As I know DIYINHK is still setting AK4490 kit as un-balanced configuration.
The new shield will replace the SE one? Actually, I don't care you raise the price if cost is an issue. But, I wish your DAC board is fully matched with your preamp project.
I have no problem with you or other saying that they want the Balanced configuration instead. No matter what, if you choose to add an preamp later, the board will be fully matched.
In single ended configuration the preamp's balanced input will take the inverted signal from the GND terminal on the output stage to compensate for differences in the GND path, but signal to noise ratio will be higher with an balanced output stage of course.
Let me now how many of you want an:
1) Variable balanced output (+ singled ended) instead with MAS6116 in the path controlled by the mixer settings from the USB host.
2) Fixed balanced output (+ single ended)
3) single ended only.
I will quickly calculate the difference. The early bird will receive the Single ended output stage as well, as balanced will be a bit delayed (8 working days)
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You cannot compare my design with DIYINHK. My PCB has high performance voltage regulators in every stage separating the different voltages on the AK4490.
I use Nichicon Polymer capacitor (8mOhm ESR and sub 20mOhm to a few MHz).
PCB i 4 Layer for optimum PCB layout.
I use Nichicon Polymer capacitor (8mOhm ESR and sub 20mOhm to a few MHz).
PCB i 4 Layer for optimum PCB layout.
Rogerchau i am going to use discrete opamp for the balanced ones. They will be a bit more advanced than the one used in the TSSA V4/V8 frontend as you have seen in the TSSA V1.7 thread.
For the Fixed balanced out it will be around 90 - 100€ extra for the output shield with discrete opamps.
It consists of 6 discrete opamps so it is really packed....
For the Fixed balanced out it will be around 90 - 100€ extra for the output shield with discrete opamps.
It consists of 6 discrete opamps so it is really packed....
I love the idea of fixed balanced + SE output which is your option #2 but option #1 is also interesting for as long as it will work in Volumio or RuneAudio for me. The specs of the MAS6116 seems to be nice as well.
Ciao!
Do
Ciao!
Do
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I am in for option 2) as well.
I find variable volume only operated by software slightly dangerous: it is easy to damage your ears by accident. Adding a physical volume control somewhere in the chain (in the form of volume knob/buttons,...) is probably safer.
I find variable volume only operated by software slightly dangerous: it is easy to damage your ears by accident. Adding a physical volume control somewhere in the chain (in the form of volume knob/buttons,...) is probably safer.
Balanced signaling has its place in many ways but it also have some inconveniences. One of them is that it is very hard to make an analog volume control that maintaines the balanced signal.
DAC pre-order is as following:
stajo = 1
pinnocchio = 1
Press57 = 1
Myint67 = 1
rogerchou = 1
vitalica = 1
pdb = 1 (SE)
Early bird 216€ + shipping
After the 1. June 2015 236€ + shipping
Kit contains USB DAC mainboard, output shield, single ended, power cable assembly and USB Stick with Windows driver and documents
stajo = 1
pinnocchio = 1
Press57 = 1
Myint67 = 1
rogerchou = 1
vitalica = 1
pdb = 1 (SE)
Early bird 216€ + shipping
After the 1. June 2015 236€ + shipping
Kit contains USB DAC mainboard, output shield, single ended, power cable assembly and USB Stick with Windows driver and documents
Agree. Once (actually twice!) I listened on headphones when suddenly there was a glitch in the playback software / driver that put white noise at full volume into my ears... it was a - how do I put it - interesting experience...! You could use both a software solution and a pot as a safety precautions if you don't have a motorized pot or an electronic / LDR volume control. I don't know how the MAS6116 solution works. Maybe it is safer?
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I am taking a long vacation right now. I respect and follow the final choice here.
Sonny, do you have any good idea at analog volume control for balanced configuration? Besides, i am a little bit confused about your preamp idea. The balanced discrete opamp output stage you mentioned above is for ak4490 dac, and then you will develop another discrete buffer with volume control IC for your preamp? So, my final solution might be ak4490 DAC with balanced discrete output stage + discrete balanced buffer with volume contro IC +V4 amp?
Sonny, do you have any good idea at analog volume control for balanced configuration? Besides, i am a little bit confused about your preamp idea. The balanced discrete opamp output stage you mentioned above is for ak4490 dac, and then you will develop another discrete buffer with volume control IC for your preamp? So, my final solution might be ak4490 DAC with balanced discrete output stage + discrete balanced buffer with volume contro IC +V4 amp?
I can see it from your point of view.
If you are choosing the preamp i will make for this one, you will only need a fixed output from the DAC.
The discrete balanced buffer with volume control will be made of the MAS6116 attenuator chip. It is a thin film resistor network with CMOS switches. It was originally made by wolfson micro. It is designed to use an external opamp in this case it will be a discrete opamp.