Hi guys,
I`m working on a little project. Currently, I own an Epiphany O2/ODAC headphone amp, which I`m very happy with. I use a Raspberry Pi as a FLAC streamer. Both currently need an adapter for power.
What Ì would like to do is add a Box Enclosure B3-160 enclosure to house
As I have no experience in building this, I have some questions that I was hoping you could help me out with.
Thanks in advance for your help!
Best regards,
Sarion
I`m working on a little project. Currently, I own an Epiphany O2/ODAC headphone amp, which I`m very happy with. I use a Raspberry Pi as a FLAC streamer. Both currently need an adapter for power.
What Ì would like to do is add a Box Enclosure B3-160 enclosure to house
- the Raspberry Pi, to work as FLAC player
- an 230VAC connection to hook it up to a power socket
- a 230VAC to 5V 2.1A PSU to power the Pi
- a 230VAC to 15VAC 333mA transformer (Myrra 44232), to power the O2/ODAC
- a power jack to deliver 15VAC out
As I have no experience in building this, I have some questions that I was hoping you could help me out with.
- I currently use a 230VAC-12VAC 250mA adapter. If I want to replace this with the Myrra 44232, is that the only component I need? (The O2/ODAC needs 12-20VAC to work properly, rated at >200mA, so I think the Myrra should work)
- Does anyone know of a PSU I can hook up to 230AC, and have a USB port out? I only found this regulated switching PSU on DealExtreme, which provides the power, but no USB port.
- What sort of grounding is needed? Both adapter I now use have no grounding, so perhaps I should not make a grounded 230VAC connection?
- Does putting these elements in one enclosure create any interference issues?
Thanks in advance for your help!
Best regards,
Sarion
O2 doesn't requires AC traffo having "Earthing" point.2 pin AC-AC stepdown Wallwarts are OK. 12V AC is bare minimum. No need to go for 15V AC if you face no problem or don't drive low impedance low sensitivity h/p(I don't). The entire casing (if metallic) is grounded thru audio i/p common Gnd of O2.
As for 230V AC to 5V DC for pi- have you tried smartphone chargers (Most of them are 1.4A or above)? They are also 2 pin type with floating ground. You might get tingling sensation on O2's metal body when used with pi.
The -ve of pi, ODAC & common Gnd of O2 incl bodywill all be "tied together" once you connect all of them electrically.
Post all your O2 related queries on http://www.diyaudio.com/forums/head...ective2-o2-headphone-amp-diy-project-461.html
As for 230V AC to 5V DC for pi- have you tried smartphone chargers (Most of them are 1.4A or above)? They are also 2 pin type with floating ground. You might get tingling sensation on O2's metal body when used with pi.
The -ve of pi, ODAC & common Gnd of O2 incl bodywill all be "tied together" once you connect all of them electrically.
Post all your O2 related queries on http://www.diyaudio.com/forums/head...ective2-o2-headphone-amp-diy-project-461.html
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Hi guys, thanks for your replies.
Indeed, I do have the wall warts at the moment, but I like to move around my stuff sometimes, and it`s a lot of clutter now. I`ll be moving the power input from the front to the rear of the O2, so I just have an AC lead to the new box, and an AC lead + USB cable from the rear of the new box to the rear of the O2.
Is it a good idea to use the insides of the wall warts, and put them in the new (metal) enclosure, together with the Pi? I could try mounting them on a project board...
Indeed, I do have the wall warts at the moment, but I like to move around my stuff sometimes, and it`s a lot of clutter now. I`ll be moving the power input from the front to the rear of the O2, so I just have an AC lead to the new box, and an AC lead + USB cable from the rear of the new box to the rear of the O2.
Is it a good idea to use the insides of the wall warts, and put them in the new (metal) enclosure, together with the Pi? I could try mounting them on a project board...
Alternatively, I might use a 220-12VAC wall wart, and connect that to the box. Then I just put a 12VAC-5VDC 2A converter in the box to power the pi. Ideally it would have a USB out, so I can easily power the pi. Perhaps that's a safer option, with no 220VAC in the box. Any suggestions for this type of converter?
This looks pretty good to me. I see is enclosed in plastic, would it not get too hot? Not sure what the loss would be, but it could supply 2A x 5V = 10W
AC DC Buck Converter Step Down Module Power Supply AC 7V 36V DC 8 52v to DC 5V | eBay
Also, I could just split the 12vac plug from the wall wart with this, to power both boxes, right?
http://www.ecolocityled.com/product/male_2_female_barrel_connector
I suppose I would need a more powerful wall wart though. 2A on 5V + 50% loss = 15W additional, so 15W/12V = 1,25 A additional to power the pi?
Sorry for the noob questions & thanks for your patience and help
I'll show a 3d model of what I am building, and pictures once I'm done or at least started
AC DC Buck Converter Step Down Module Power Supply AC 7V 36V DC 8 52v to DC 5V | eBay
Also, I could just split the 12vac plug from the wall wart with this, to power both boxes, right?
http://www.ecolocityled.com/product/male_2_female_barrel_connector
I suppose I would need a more powerful wall wart though. 2A on 5V + 50% loss = 15W additional, so 15W/12V = 1,25 A additional to power the pi?
Sorry for the noob questions & thanks for your patience and help
I'll show a 3d model of what I am building, and pictures once I'm done or at least started
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I don't mean to hijack the thread, but I am trying to do the same (or similar) thing with my Pi. I want to have a single enclosure that houses both a headphone amp and a Pi.
I am building a Millet tube headphone amp that uses a 24VAC wallwart. The Pi calls for 5V using a micro USB plug. I own a wallwart for each, however I would like to have only one plug going to the enclosure. There are two "easy" ways to do it, neither of which I like. Run 120VAC to the enclosure, and have an outlet within the enclosure and plug both wallwarts into it, securing them somehow. The second option is simliar, only break the wallwarts open and take out their internals, and run the 120VAC to a set of terminals, and connect the internals of the wallwarts to that.
The option I would prefer is to use the 24VAC wallwart that I have for the Millet and convert that to 5VDC. Any suggestions on how to do that? I am not an electrical engineer, but I do have basic electrical knowledge, I am just looking for someone to help point me in the right direction. Bonus points if it is a "clean" power source, as I have heard you can clean up the "brightness" of the Pi with a well regulated PSU.
Thanks in advance for your help!
Mike
I am building a Millet tube headphone amp that uses a 24VAC wallwart. The Pi calls for 5V using a micro USB plug. I own a wallwart for each, however I would like to have only one plug going to the enclosure. There are two "easy" ways to do it, neither of which I like. Run 120VAC to the enclosure, and have an outlet within the enclosure and plug both wallwarts into it, securing them somehow. The second option is simliar, only break the wallwarts open and take out their internals, and run the 120VAC to a set of terminals, and connect the internals of the wallwarts to that.
The option I would prefer is to use the 24VAC wallwart that I have for the Millet and convert that to 5VDC. Any suggestions on how to do that? I am not an electrical engineer, but I do have basic electrical knowledge, I am just looking for someone to help point me in the right direction. Bonus points if it is a "clean" power source, as I have heard you can clean up the "brightness" of the Pi with a well regulated PSU.
Thanks in advance for your help!
Mike
Here is a link to the wall wart.
It is 120VAC to 24VAC 1A 32W.
I feel that this is some pretty egregious thread jacking, so if the OP would prefer, I would be happy to create my own thread, but I feel we have the same goal in mind so I was trying not to clutter the forum. I'm new here, so please stop me if I am out of line. OP if you would prefer I start my own thread, let me know!
Thanks,
Mike
It is 120VAC to 24VAC 1A 32W.
I feel that this is some pretty egregious thread jacking, so if the OP would prefer, I would be happy to create my own thread, but I feel we have the same goal in mind so I was trying not to clutter the forum. I'm new here, so please stop me if I am out of line. OP if you would prefer I start my own thread, let me know!
Thanks,
Mike
Thanks Sarion, I think you hit the nail on the head with that AC/DC converter. I am going to order one tonight. When you get yours, let me know how it goes.
I don't know how well the wallwart will handle sharing it's amperage. I don't know how much draw it has when the amp is running, but there are some known, reference voltages that I can measure before hooking up the pi and after and see if the power of the amp suffers. I will let you know my results.
I don't know how well the wallwart will handle sharing it's amperage. I don't know how much draw it has when the amp is running, but there are some known, reference voltages that I can measure before hooking up the pi and after and see if the power of the amp suffers. I will let you know my results.
This looks pretty sketchy to me. You can't trust the quality of that ebay stuff.
I would run the (very good) headphone amp from its own power supply to isolate digital noise from the quality audio circuitry.
I get a little impatient so I ordered one of these.
http://www.amazon.com/gp/product/B00R5I3VTW
I also ordered two of the ebay converters, but those will take a couple weeks to arrive. If anything, I'll at least have a couple options in case one doesn't work. Or for multiple projects in case I like how this turns out.
http://www.amazon.com/gp/product/B00R5I3VTW
I also ordered two of the ebay converters, but those will take a couple weeks to arrive. If anything, I'll at least have a couple options in case one doesn't work. Or for multiple projects in case I like how this turns out.
Hi Paulb,
You have a good point. Would there be a way to tell if there would be noise interfering with the amp? I could purchase the Amazon converter Marzie found, and give it a try.
If it would work well, that would allow me to put the Pi in an identical enclosure to the one the O2 is in, a Box Enclosures B2-080. That would be perfect! Worst case, I have to power both boxes with separate wall warts.
You have a good point. Would there be a way to tell if there would be noise interfering with the amp? I could purchase the Amazon converter Marzie found, and give it a try.
If it would work well, that would allow me to put the Pi in an identical enclosure to the one the O2 is in, a Box Enclosures B2-080. That would be perfect!
Worst case, I have to power both boxes with separate wall warts.Cool, I`m very curious to hear how it works out. With >96% efficiency, I guess there is very little to fear in terms of heat.
Now to find someone selling a similar unit to the Netherlands...
I think the one I got from Amazon is the same as yours from ebay, just with a different label. They probably came from the same factory.
The verdict is that it works. I had the Pi powered up as well as my headphone amp. The pi output to the TV thru HDMI without issues, but when I switched over to using the headphone jack into the amp, there was a lot of noise. There was a very loud hum, but I believe that is a grounding issue, as my amp is not in a case yet, and the hum changed when I touched different components. There was a background static hiss as well, but that may be due to the crappy headphone out on the pi. When it is all cased up and wired to the RCA outs of the DAC board, I will have a better answer and that is a few weeks away.
Just FYI, if you want them to have their own on/off switches, you will want a DPST switch. I had SPST thinking I could just break one leg of the AC on each
But if the other device was powered on, because they had one leg of the AC tied together, they would both be on. This is probably pretty bad for the devices, as they were only getting 1/2 the AC wave, so I only did it for a few seconds before I figured out what was going on. I might not be correct in describing what is happening electrically but that's how I understand it.
Also I think I should add a "soft off" board for the pi, as dropping power to it is bad.
Here is a link to my build on head-fi.
http://www.head-fi.org/t/794873/tube-amp-raspberry-pi-dac-build
The verdict is that it works. I had the Pi powered up as well as my headphone amp. The pi output to the TV thru HDMI without issues, but when I switched over to using the headphone jack into the amp, there was a lot of noise. There was a very loud hum, but I believe that is a grounding issue, as my amp is not in a case yet, and the hum changed when I touched different components. There was a background static hiss as well, but that may be due to the crappy headphone out on the pi. When it is all cased up and wired to the RCA outs of the DAC board, I will have a better answer and that is a few weeks away.
Just FYI, if you want them to have their own on/off switches, you will want a DPST switch. I had SPST thinking I could just break one leg of the AC on each
But if the other device was powered on, because they had one leg of the AC tied together, they would both be on. This is probably pretty bad for the devices, as they were only getting 1/2 the AC wave, so I only did it for a few seconds before I figured out what was going on. I might not be correct in describing what is happening electrically but that's how I understand it.
Also I think I should add a "soft off" board for the pi, as dropping power to it is bad.
Here is a link to my build on head-fi.
http://www.head-fi.org/t/794873/tube-amp-raspberry-pi-dac-build
In terms of powering down the Pi, you may risk corrupting the sd card if you just pull the plug. I found this very nice piece of kit:
https://lowpowerlab.com/shop/ATXRaspi-R2
I hope you are able to solve the noise issues!
https://lowpowerlab.com/shop/ATXRaspi-R2
I hope you are able to solve the noise issues!
I ordered that ATXRaspi, but I had to change my button selection, as it needs to be a Off/NO-Momentary switch (from what I can tell.) I spent a lot of time trying to find the switches I had originally picked out, and they matched, so finding new ones in the same style was a pain in the butt. Also, it would be nice if I could have dropped power to the AC/DC-DC converter, but that will always have power to it now. Also, I had to order all the gear for interfacing with the GPIO pins, jumper wires, header pins, etc. A lot of people that work with the Pi already have that, but I don't do a lot of breadboarding with it, so I had to buy it.
I plan to put a longer update about the build on my head-fi thread. But I will keep this thread specifically about the power.
I plan to put a longer update about the build on my head-fi thread. But I will keep this thread specifically about the power.
FYI, I updated my build thread at head-fi.org.
Short version: I got the ATXRaspi installed and working, kind of. The script on his website is not meant for the version of linux that RuneAudio (and probably Volumio) run on the backend. I had to make a few changes that I found here in order for RuneAudio to work. Make sure you use the "Type=simple" that it says farther down the thread.
But even after that, the reboot function does not work. RuneAudio comes up with a spinning wheel, and an error at the bottom, and won't play music. I can reboot manually from a terminal session and it comes back fine, but not from the ATXRaspi. I looked at his script and it seems dead simple, so I don't know what it is doing differently on reboot. But shutting down via ATXRaspi and starting back up, it comes back up just fine.
Short version: I got the ATXRaspi installed and working, kind of. The script on his website is not meant for the version of linux that RuneAudio (and probably Volumio) run on the backend. I had to make a few changes that I found here in order for RuneAudio to work. Make sure you use the "Type=simple" that it says farther down the thread.
But even after that, the reboot function does not work. RuneAudio comes up with a spinning wheel, and an error at the bottom, and won't play music. I can reboot manually from a terminal session and it comes back fine, but not from the ATXRaspi. I looked at his script and it seems dead simple, so I don't know what it is doing differently on reboot. But shutting down via ATXRaspi and starting back up, it comes back up just fine.
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