Well, for that bord there is only one power inlet - 3,3V. But the manual speak of separate LDO for 1V so perhaps its OK. It sound s good 🙂 and apparently can feed OSCs separate 3,3V (this I need to try).
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No, sorry, a bit OT as it was not about SU-1, but still XMOS powering (see link above)... won't happen again...
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Crocodile clip on the ground... If it is coused by some radiation, then I should get a similar pictures at another regulators, but no
I take it here because i just have it unused and it is very easy to set voltage with it, also because of specs in datasheet that says typical active VDD current - 300 mA.
I'm also thinking now about how to get I2S from PC without USB
External DACs are putting the cart in front of the horse.
Many years ago I built better DACs (then not that difficult as the standard was not high) for building in Akai CD-73/93 and Teac VRDS CD players and this approach pretty much automatically resulting in lower jitter seems more optimal in streaming audio players too. More efficient as these often are multifunctional and a kind of digital hub.
The suspicion is that we won’t see a source with optimal DACs as then a business model of many will shatter to pieces. The Wiim Ultra and maybe better the Eversolo DMP players seem suitable.
Many years ago I built better DACs (then not that difficult as the standard was not high) for building in Akai CD-73/93 and Teac VRDS CD players and this approach pretty much automatically resulting in lower jitter seems more optimal in streaming audio players too. More efficient as these often are multifunctional and a kind of digital hub.
The suspicion is that we won’t see a source with optimal DACs as then a business model of many will shatter to pieces. The Wiim Ultra and maybe better the Eversolo DMP players seem suitable.
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Small indeed. The thinking before acting method versus acting before thinking method conflict pictured in real life 🙂 I could have easily used 2 x 0.9V and 1 x 3.3V regulators instead of just 1 x 0.9V for the PLL as they hardly take board space.
Anyone in F, B, D or NL can have a PCB for shipping costs. Just send a PM.
Anyone in F, B, D or NL can have a PCB for shipping costs. Just send a PM.
Attachments
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So you see noise on the ground wire. Use a spring at least.
You can do a simple test - connect your crocodile (alligator clip) to the probe tip and touch it to the ground of the circuit board. Just ground.
AMS1117 in SOT223 also can provide 300mA? even more.
You can take it exactly to 3.3V fixed, of Adj version and set the voltage by 2 resistors.
SPDIF (Coax or Optical), if your PC have corresponding output and SPDIF-receiver in your DAC.
If you do not take care of jitter and do not have any jitter reducing hardware.
Alex.
AMS1117 is nice. It is often chosen for its relatively low dropout voltage and 800 mA or 1A capability. It is however not ultra low noise.
TPS7A20xxPDBVR are ultra low noise, have way lower dropout voltage and higher PSRR. They cost 34 Eurocent ex taxes. Maximum 300 mA and 0.3 ms softstart though.
TPS7A20xxPDBVR are ultra low noise, have way lower dropout voltage and higher PSRR. They cost 34 Eurocent ex taxes. Maximum 300 mA and 0.3 ms softstart though.
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I wouldn't know but I read contradicting things in this very thread. Initially it was said linear regulators do not result in better sound as compared to switchers. Then it is said they do result in better sound. If so I can imagine a cheaper, lower noise linear part with lower dropout voltage and higher PSRR to be superior (or at least a possible alternative). The ultra low cost SU-1 is quite OK as it is (despite the horror stories), making it better probably needs a complete redesign of the PCB and power supplies which is somewhat against its reason for existence.
Since I have become external DAC-fobic I also avoid absorbing too much information on XMOS 🙂 It is all a bit a waste of time.
Since I have become external DAC-fobic I also avoid absorbing too much information on XMOS 🙂 It is all a bit a waste of time.
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You don't need a low-noise LDO for the XMOS I/O interface. At all!
As I said before - you only need a low-noise LDO here if you also use it to power the audio oscillators.
But that's not the right way! It is not good to feed audio oscillators and CPU from one LDO!
Better to use a separate low-noise LDO just for the oscillators.
For example, LP5907-3.3 or TPS7A2033PDBVR from the 5V rail.
Alex.
It may not be needed but if I can choose an equally cheap but better specced part that would not hurt would it? I could have replaced all the switchers in SU-1 for linear ones.
Ha I see, just 1 PSU is not the way to go but it was also not OK to have a coil and cap for the PLL PSU pin isn't it? Things are as they are and I will only build the tiny PCB for PLL PSU and be done with it.
A complete redesign of the SU-1 mainboard and power supply lines is not my scope of interest really. A complete redesign of the internal DAC part and/or replacing the SMPS for a linear PSU of my audio player maybe is. 2025 will likely be an external DAC-less year.
Ha I see, just 1 PSU is not the way to go but it was also not OK to have a coil and cap for the PLL PSU pin isn't it? Things are as they are and I will only build the tiny PCB for PLL PSU and be done with it.
A complete redesign of the SU-1 mainboard and power supply lines is not my scope of interest really. A complete redesign of the internal DAC part and/or replacing the SMPS for a linear PSU of my audio player maybe is. 2025 will likely be an external DAC-less year.
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Of course it can, but how to get 0.95-1V from it for core VDD supply?
No, of course it won't hurt.
It's just that 1117 in SOT223 or TO263 dissipate heat better and are easier to solder to an existing board with surface mount (wires) than SOT23-5.
Keep in mind that if all regulators are linear, they will dissipate amount of power and will require good heatsinks. Especially 1v rail.
By the way, why I use 2 linear regulators in series on the 1V line - one 1.8V and the second 1V:
1) Historically, this came from the XMOS XS1 processor with an external USB PHY, which requires the 1.8V line.
2) Even with the XMOS XCORE200 family (208, 216, etc.) I still use the same thing - to spread the heat between the 2 regulators (but in some designs, this 1.8V is switcher).
Alex.
Yes familiar stuff to those that grew up with linear/analog stuff.
Meanwhile to me the best XMOS seems to be no XMOS.
If the industry would see money in it we would have an M2 like slot for updating clickable DAC modules in devices and standardized PSU voltages to predefined pins and onboard uLDO regulators on the M2 module. Output stages are datasheet solutions in most cases anyway. Not much new to invent either except extra features no one uses, fancy marketing terms and such gibberish.
Meanwhile to me the best XMOS seems to be no XMOS.
If the industry would see money in it we would have an M2 like slot for updating clickable DAC modules in devices and standardized PSU voltages to predefined pins and onboard uLDO regulators on the M2 module. Output stages are datasheet solutions in most cases anyway. Not much new to invent either except extra features no one uses, fancy marketing terms and such gibberish.
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Who said that 1V should be obtained from 1117 to 3.3V?!
Of course, it is possible, but there is no point - too much heat will be generated on it.
I have already said how I did it - from 5V there is a regulator for 1.8V, linear (1117-1.8) or switcher (LM3671MF-1.8), and after there is a linear one for 1V (TPS72010 or AP7365-10YG-13).
3.3V - separate 1117-3.3 for XMOS I/O and I2S isolators (Si8661).
Alex.
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XMOS (XCore) is not the only one, there are interfaces based on other processors - Atmel, Microchip, STM, SaviTech, Tenor, CMedia, ComTrue...
You can use Amanero, Xing(?), etc.
I had certain reasons to choose XMOS at one time.
Alex.
That is I'm asking about, 300mA from TPS are enough for any audio stream for core ? Seems AP7365 is better choice.
btw I have such one board on Savitech SA9227, sounds very good for it's price
return to LP/tapes?