Just ordered one of these.
Are there any guides on powering the analogue circuits separately?
Date
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82 comments
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HiFiBerry team Hi Terry,
we don't have the guide ready yet. Basically you need to remove a resistor and connect 5V to the pins marked on the board.
Best regards
Daniel -
Nico Oosterwijk Daniel,
Which resistor would that be?
kind regards,
.Nico -
HiFiBerry team It is R14 located in the corner near the 40 pin header
Best regards
Daniel -
Scott Kramer Looks like that is a 0 ohm resistor... so basically a jumper?
Once that is removed, and power the dac with it's own 5V power...
Can I also add a header to the pi's 5V in and power that separate, will the shared ground cause a problem? -
HiFiBerry team Yes, this is a 0 Ohm resistor. When you remove it, you need to power the analog part of the DAC via the 5V pins on the DAC+.
Shared ground between Raspberry Pi ground and a seperate power supply for the analog part is necessary, otherwise it won't work. Both grounds are connected on the board.
Best regards
Daniel -
info Hello, i ordered the ne DAC + Pro yesterday. I would like to use a separate power supply (superregulator) for the DAC, how much current does it need?Just +5V and ground needed?
Any instructions available for connecting to anaother DAC with i2S yet?
Thank you
Best Regards
Daniel
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HiFiBerry team Hi Daniel,
check out this article on external I2S connectivity:
http://support.hifiberry.com/hc/en-us/articles/205711451-DAC-Pro-connect-external-I2S-DACs
For the external power supply, you need to remove R14 (near the 5V header). Current consumption is quite low, we haven't specifically measured it, but it should not bore more than 20-30mA. If you are already using an extra power supply, I would recommend at least 100mA.
Just note that soldering on the board voids warranty. Shouldn't be an issue, but I just want to note this. I'm interested to see your final device when it is ready.
Best regards
Daniel -
info I got the DAC+ Pro today, just looked at it and i have two questions right now:
On the left side near the 5V +/- is a bare round space - seems a not installed Elko?
Or what is the use for that?
The L GND R right near the RCA Inputs - are for input/output connecting in case iwant to use other connectors than the onboard RCA?
Thank you
P.s. I will post photos when iam finished ;)
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HiFiBerry team While we think and our measurements show that an additional electrolytic capacitor won't improve the performance, you can install an electrolytic capacitor there.
L/GND/R is an output that just connected in parallel to the RCA jacks.
Best regards
Daniel -
info Hello Daniel,
thanks for your fast answer :)
What kind electrolytic capacitor? Normal kind, or bipolar? How many Farad?
Okay just as i thought :)
All the best
Daniel
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HiFiBerry team Hi Daniel,
the circuit has been designed without this capacitor. Therefore we can't recommend a specific value. I recommend keeping the circuit as it is.
Best regards
Daniel -
Adrian Adrian Hi,
Could you help me with a few questions regarding the DAC+ Pro?
1. I mainly power my RPi 2 with a 16.000 mAh Xiaomi powerbank: http://www.mi.com/en/pb16000/ . Before adding the DAC+ Pro to the RPi, after shutting down Kodi (Openelec), the power bank would continue to supply power to the Pi for about ten seconds and then turn off completely (the red led on the Pi would turn off also). I think that's because the Pi no longer draws any current after being shut down and the power bank goes idle. To turn the Pi on, I just had to press the power button on the battery.
With the D+P added, the power bank no longer turns off and the Pi's red led remains lit continuously (although the green led on the D+P turns off after powering off Kodi). Could it be that the D+P is drawing some power while the system is off? Would there be a fix to turn the system off completely as before?
2. I applied the external power mod to the D+P as per your instructions here: https://support.hifiberry.com/hc/en-us/articles/205732441-DAC-Pro-external-power-supply . I de-soldered resistor R14 and wired a micro USB female connector to the P3 header and then powered the D+P from the power bank. Nothing happened - neither the Pi or D+P would turn on. If I unplugged the micro USB cable from the D+P and plugged it into the Pi, this turned on but not the D+P. I also tried this with my 1.8A phone charger to the same effect. After soldering back the R14 resistor everything worked perfectly - I can now power the system (D+P and Pi) from the power bank through the P3 header of the D+P alone. Or the "normal" way, through the micro USB on the Pi. After several sound comparisons (using latest Moode player) I agree that the system sounds better when powered through the P3 header on the D+P.
But is it OK that it works only with that R14 resistor in place (as opposed to your instructions)? Although I have the patience to solder a few bits, even smd, I'm not much of an electronics guy and I need your advice here, please.
As for the sound quality - unbelievable; much better than my (much appreciated) Audioquest Dragonfly v1.2.
3. I noticed the red led on the Pi blinking inconsistently while listening to the system powered from power bank through the P3 header on the D+P (the music plays flawlessly though). More on Kodi - with TV on, less on Moode - TV off. All USB ports free, music fed from wired LAN. The power bank specs state that "Each of the two ports supports 5.1V/2.1A output" and I only use one port. Although the battery was displaying only half charge at that time, maybe I should check the output on these ports as I understand that a blinking red led on the Pi means not enough power (undervoltage?). I'm not sure what that R14 resistor does and I avoided powering both the Pi and D+P at the same time.
Hoping you could help me a bit with these rather long questions, I want to thank you guys for your excellent product, fast shipping and support.
Adrian
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HiFiBerry team 1. The DAC+ Pro will draw some power as the analog stage is always powered. This can't be changed.
2. The external power supply shown at https://support.hifiberry.com/hc/en-us/articles/205732441-DAC-Pro-external-power-supply is only powering the analog part of the circuit, not the Raspberry Pi and the Digital part.
3. The red LED is indicating that the external power supply drops below 4.6V. Your power pack seems to provide less stable voltage than it is supposed to do.
Best regards,
Daniel -
Adrian Adrian Hi Daniel,
Thank you for going through my questions. You helped me understand the obvious about powering separately the analog circuit on the DAC+ Pro. I de-soldered again the R14, connected both ports of the power bank - one to the DAC+ Pro and the other to the Pi and, of course, it works. Yes, both ports of the (FULLY CHARGED ;-) power bank are now driving the entire system with no problem and no blinking red LEDs.
...and the sound...BEAUTIFULL!
With best regards,
Adrian
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John Chee Hi Daniel,
I am pretty happy with the DAC+ Pro. Great product! Upon serious listening via a headphone, I could hear some USB noise from the RPi. Thus, I am planning to power the DAC+ Pro with linear power supply as you mentioned above and am about to order a linear power supply unit. For sharing ground between the DAC+ Pro and RPi 3, should I use the same linear power supply unit to power the RPi and DAC+ Pro via 1) using a USB hub or 2) need a linear power supply with dual USB ports)?
Thanks in advance,
John
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HiFiBerry team Hi John,
why do you want to use an USB hub? You should power the DAC+ Pro directly (or the DAC+ Pro and the Raspberry Pi).
Best regards
Daniel -
John Chee Hi Daniel,
I was just trying to find a way to have a power supply unit that can power the DAC+ Pro and the RPi 3 with a sharing ground. Seems like a single unit of 5V linear power supply with dual USB ports is the way to go (similar to what Adrian [above] did with a power pack but from a linear PSU instead in my case). Does it make sense?
Thanks,
John
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HiFiBerry team Hi John,
ground is always connected when you plug to board onto the Raspberry Pi. Just connect the power supply to the Raspberry Pi or the DAC+ Pro and you're fine. No need for 2 separate connections.
Best regards,
Daniel -
John Chee Hi Daniel,
Thanks for the clarification. I was just trying to separate the power supply for the DAC+ Pro from the RPi 3 as mentioned here --> https://support.hifiberry.com/hc/en-us/articles/205732441-DAC-Pro-external-power-supply. It seems to be working fine now, just waiting for the arrival of the linear PSU to replace my regular adapter.
Regards,
John
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GJS Daniel,
Would it make a difference if you connect a linear power supply to the micro USB port on the RPI, or to the HiFiBerry DAC + Pro?
Thanks.
Jacob.
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John Chee Hi Jacob,
I use a linear power supply for the DAC+ Pro only and it has a very quite noise floor, a huge improvement. Separating the power supply for the RPi and DAC+ Pro would give better result than not separating them. But, giving the DAC+ Pro linear power supply makes more sense to me as that's where the sound is converted.
Hope this helps,
John
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GJS Thanks John!
Did you de-solder the resistor R14 and connect your Linear PS to the pin header P3? If you do this, do you then need 2 power supplies, i.e., one to power the RPI, and one to power the DAC + Pro?
Jacob.
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John Chee Hi Jacob,
Yes, I have two power sources now. I did exactly what the instruction said. Linear PS go to the pin header P3. For RPi, I use a regular power supply to the micro USB. The result is great. It's worth the effort.
Regards,
John
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GJS Thanks again John!
Which Linear PS do you use?
I ordered this one, but I am not sure how good it will be...
Jacob.
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John Chee Hi Jacob,
I have two for two DAC+ Pros in two rooms, both are working well so far:
1) From China: http://www.ebay.com/itm/161922445306
2) From Hong Kong: http://www.ebay.com/itm/281391134125
From the outside and holding at hand, the second one from Hong Kong is more robust than the first one from China. I wouldn't know which has better components inside. When I ordered the first one, I just went for whatever I could find in a low price to test things out. In some HiFi forums, someone praised the company in Hong Kong on eBay. It seems like the one from Hong Kong is gearing towards audiophiles. If the price difference is not significant to you, I would suggest the one from Hong Kong. Note that these two units use different DC power plugs.
John
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GJS thanks John.
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pierre hello,
i too just bought a linear power supply to power my dac+ pro
i hooked it up to the dac+ pro and Rpi is powered via the regular usb power supply
i wonder if it would be better ton power the pi with the linear PS ? Theoritically it shoud be better as the pi would then power the dac with "clean power"
The linear PS is rated at 2A so using it just for the dac is a waste of power...
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John Chee Hi Pierre,
Yes, having linear power source benefit all electronics. 2A for both tthe RPi and DAC+ Pro is plenty.
For my linear PSU from China, there are two outlets with a combined 2.5A max output. I've just tried to use the second outlet for my RPi 3 concurrently, and don't detect any sonic differences. My regular power supply for the apartment has been pretty stable, anyway. Therefore, my setup may not be a good representation for this experimentation. For those who has regular power supply that is not as stable, I can see the benefit. Anyhow, I believe that there is a voltage regulator onboard of RPi 3 already.
A separation of power supply for the DAC+ Pro is to avoid any impact on voltage for the HAT (DAC) due to fluctuations of the power draw from RPi. If your linear PSU also has two outlets, you might want to check with the manufacturer and see if there is any interdependency between the two outlets, or each stands on its own.
Enjoy the music!
John
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Danny Dear all Raspberry and DAC users :-)
Thx for all your helpfull comments !
I have a Hifi-Berry (Raspberry Pi B and DAC +Pro).
Last weekend i made the instructions: de-solder the resistor R14 and connect mij external Linear 5V Power supply,
I followed the discription in this link:https://support.hifiberry.com/hc/en-us/articles/205732441-DAC-Pro-external-power-supply
I have this Linear power supply: http://www.ebay.com.au/itm/111981585915
I read somewhere that the Linear Power supply can also feed the Raspberry.
But i have to put in also the standard USB Power supply in de Raspberry to make it work.It sounds much better with the Linear power supply directly to the Dac +Pro.
But doesn't the extra USB standard Power supply effected the sound quality aswel ?Bye Danny
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GJS Does anyone have experience with the iFi iPower power supply unit? iFi claims that it is even quieter than linear power supply. And it cheap ($50), compared to linear power supplies.
http://ifi-audio.com/portfolio-view/accessory-ipower/
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