Yep, that's my take on the first variant as well. The accompanying graphic on the PDF clinches it for me.
Generally, soldering pins / wires directly to the board results in better contact / signal transfer than using a terminal of some sort. Use terminals only if you want it to be easy to disconnect.
Edit : it would depend on what PSU you're going to use too I think. If the PSU uses 4-wire connections (the various Salas shunt regulators come to mind), it won't matter much if you use terminals or not. Otherwise, I'd prefer soldering in.
About the difference in sound quality ... I can only make theories at this point. Hopefully someone who has experimented would chime in. Anyway, what I think is, it would be better to have the 7.5V powering the DAC board and the XMOS powered from USB. Rationale : this option would give you galvanic isolation, your unit won't be affected (much) by the "dirty" electrical environment from your PC.
My own unit just arrived earlier today, and I'm listening to it stock (and having a grand good time of it too
). I notice though that whenever there's a lot of activity in my laptop, I get static through my speakers. Having galvanic isolation would prevent that, I think.
Generally, soldering pins / wires directly to the board results in better contact / signal transfer than using a terminal of some sort. Use terminals only if you want it to be easy to disconnect.
Edit : it would depend on what PSU you're going to use too I think. If the PSU uses 4-wire connections (the various Salas shunt regulators come to mind), it won't matter much if you use terminals or not. Otherwise, I'd prefer soldering in.
About the difference in sound quality ... I can only make theories at this point. Hopefully someone who has experimented would chime in. Anyway, what I think is, it would be better to have the 7.5V powering the DAC board and the XMOS powered from USB. Rationale : this option would give you galvanic isolation, your unit won't be affected (much) by the "dirty" electrical environment from your PC.
My own unit just arrived earlier today, and I'm listening to it stock (and having a grand good time of it too
). I notice though that whenever there's a lot of activity in my laptop, I get static through my speakers. Having galvanic isolation would prevent that, I think.
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Thank you for your very quick answer!
So you think galvanic isolation would be useful even if i shouldn't use PC's USB 5V power (as in the "first variant" configuration)? Where could this "dirty" electrical current affect DAC board from? You think simple USB data signal (i would use a no-power USB cable) could contain this "dirty" electrical current?
Thank you in advance for your support!
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From ground wire
Try to connect Amp=> DAC (without galvanic isolation) => Computer => HDMI cable => TV => cable receiver, I've got a ground loop with a custom build USB cable without +5V wire. With the same configuration but with a galvanic isolated USB DAC the ground loop disappeared. So there is a way for interferences to propagate thru the chain.
From ground wire
Try to connect Amp=> DAC (without galvanic isolation) => Computer => HDMI cable => TV => cable receiver, I've got a ground loop with a custom build USB cable without +5V wire. With the same configuration but with a galvanic isolated USB DAC the ground loop disappeared. So there is a way for interferences to propagate thru the chain.
Really interesting! I didn't suspect such a thing...
So which one would lead to better result among these 3 configurations, considering i have to use a single 12V linear PSU shared among this DAC and a TA2024 amplifier:
1) PCM5102 powered by linear 8V PSU using a LM317 DC down volting regulator (PSU also outputs 12V for a TA2024 amplifier) + XMOS powered by 5V PC USB (galvanic isolation on);
2) PCM5102 and XMOS powered by a single 5V linear PSU (galvanic isolation off) via linking pins 1 & 2, again using down volting regulator;
3) PCM5102 and XMOS powered by 2 leads coming in parallel from a single linear PSU but using 2 LM317 DC down volting regulators set to 5V and 8V.
The difference between configurations 2 & 3 would be that in point 1) 5V power is input via a single lead to pins 1 & 2, in point 2) i would use 2 wires in parallel set to 5V and 8V via regulators to linking pins 1 & 2 and to PCM5102 pin 12.
Sorry for the little confusion i can generate
and thank you in advance!1) PCM5102 powered by linear 8V PSU using a LM317 DC down volting regulator (PSU also outputs 12V for a TA2024 amplifier) + XMOS powered by 5V PC USB (galvanic isolation on);
2) PCM5102 and XMOS powered by a single 5V linear PSU (galvanic isolation off) via linking pins 1 & 2, again using down volting regulator;
3) PCM5102 and XMOS powered by 2 leads coming in parallel from a single linear PSU but using 2 LM317 DC down volting regulators set to 5V and 8V.
The difference between configurations 2 & 3 would be that in point 1) 5V power is input via a single lead to pins 1 & 2, in point 2) i would use 2 wires in parallel set to 5V and 8V via regulators to linking pins 1 & 2 and to PCM5102 pin 12.
Sorry for the little confusion i can generate
In one of my setups I'm using variant 1, but this configuration is highly dependent of the quality of the power/noise from USB port. I'm quite happy with this setup with a wire headphone amp.
variant 3 sound good too if not better that 1.
Personally I will not go for 2, due to lost of the galvanic isolation.
You can experiment and listen
.Hi,
According to my opinion it's better to use external 7.5 to 9.0V PSU for PCM board (page 2 second option on PCM5102 pdf) like taisho_daniel said.
This is quite good option. On option 3 there is no galvanic isolation.
You can experiment with external PSU for USB part (separate transformer or batteries) and find what suits you.
Regards,
Joro
According to my opinion it's better to use external 7.5 to 9.0V PSU for PCM board (page 2 second option on PCM5102 pdf) like taisho_daniel said.
This is quite good option. On option 3 there is no galvanic isolation.
...
You can experiment and listen
You can experiment with external PSU for USB part (separate transformer or batteries) and find what suits you.
Regards,
Joro
Thanks to you Joro for your kind suggestion.
Unfrtunately in the DAC i'm building i cannot use a separate external PSU to supply power to USB part, the best i can do is to get a parallel output wire from the PSU that also powers PCM5102 board and a Ta2024 amplifier - using 2 DC-DC step down converters (1 for PCM5102 set to 8V and 1 for USB part set to 5V), of course.
So the only choice i can do is, given PCM5102 powered by that PSU, between USB part powered by PC USB bus and USB part powered by that same PSU.
Surely i can experiment those 2 configurations, but it would have been much more "comfortable" to avoid experimentation having a sure answer ready...
Last night received the kit and i was amazed by careful packaging and built quality.
Quick test with external dac supply is very positive to say the least.
AK4396 sounds very very detailed and way better than my EMU0202.
Overall very good product and correctly priced too!
Congratulation neighbor!
Quick test with external dac supply is very positive to say the least.
AK4396 sounds very very detailed and way better than my EMU0202.
Overall very good product and correctly priced too!
Congratulation neighbor!
Greetings panos29,
Glad to hear that you are satisfied with the board. Mine is on its way here to California. After reading your impressions, I look forward to putting it in my Buffalo IIIse and listening to some great sounding tunes...
Thanks for the update...
Regards,
vintess
Joro,
Just wanted you to know that I received your package just yesterday, here in California. As others have noted, the package was carefully packaged and the XMOS USB board carefully sandwiched in many layers of miniture bubble wrap which insured no damage on its journey to its new owner. The board looked beautiful. I can't wait to solder it in my Buffalo IIIse and listen!
So that others can see your quality workmanship on the board AND careful packaging, I am posting two photos I took.
Many thanks!
Regards,
vintess
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